2012 Final Review
Identify the independent and dependent variables from questions
Know the difference between quantitative and qualitative
Chapter 1- Wade and Omar
1.
Describe the ten levels of the hierarchy of biological organization.
a.
i. Atom—chemical building blocks of all matter
ii. Molecule—made of atoms
iii. Organelle—components of cells
iv. Cell—basic unit of life
v. Tissue—collection of cells with similar purpose
vi. Organ—specific arrangement of tissue
vii. Organ system—organs working together
viii. Organism—living being
ix. Population—organisms of same species
x. Community—all living things in an area
xi. Ecosystem—all living and nonliving things in area
xii. Biosphere—all ecosystems as a whole (Earth)
2.
Distinguish between prokaryotic and eukaryotic cells. Name examples of each.
a.
i. Prokaryotic—simple; DNA loop; ribosome is only organelle; no membrane-bound
organelles; found in bacteria and archaea
ii. Eukaryotic—complex; DNA in nucleus; many membrane-bound organelles; found in all
non-microorganisms (like plants and animals)
3.
Contrast emergent properties with reductionism.
a.
i. Emergent properties—characteristics that appear in a level of organization due to the
complex organization of lower levels
ii. Reductionism—taking apart something at a higher level of organization to see what gives
it its properties at lower levels
4.
Contrast negative feedback with positive feedback.
a.
i. Negative feedback—when a reaction or process reaches a certain point, the body reacts
oppositely to send it back to homeostasis; most feedback is negative
ii. Positive feedback—when a reaction or process strays from homeostasis, the body assists
it and increases it (ex. pregnancy—contractions are increased, which strays further from
equilibrium)
5.
Describe/contrast the three domains of life. Name example organisms in each.
a.
i. Bacteria—prokaryotic; most diverse and widespread; single-celled; ex. E. coli
ii. Archaea—prokaryotic; live in extreme environments; have much in common with
eukaryotes; ex. microorganisms in hot springs
iii. Eukarya—all eukaryotic; consists of four kingdoms: Protista, Plantae, Fungi, Animalia;
humans are of this domain
6.
Explain Darwin’s views on (a) “descent with modification” and (b) natural selection. Give examples.
a. (a) All organisms on Earth have descended from a common ancestor; over billions of years, they
have modified piece by piece. (b) Only the organisms that are strongest can live: “survival of the
fittest”; organisms that are overshadowed by others will cease to exist
2012 Final Review
7.
Why is a hypothesis often framed in the form of “If…then”? What is the difference between a theory and a
hypothesis?
a. Deduction: the “if” part is a general statement, whereas the “then” is a specific possibility that can
be tested; theories are comprehensive explanations of observations, whereas hypotheses are
possible answers that can be tested
8.
What is meant by a “controlled experiment”?
a. An experiment in which all variables are kept the same in each group (control and variable) being
tested except for one variable
9.
Explain the eleven themes that pervade all of biology.
a.
i. Emergent properties—life has hierarchical organization, with properties emerging
ii. Cell—basic unit of life; prokaryotic and eukaryotic
iii. Heritable info—continuity of life depends on inheritance of biological info through DNA
iv. Structure & function—form and function correlate
v. Environmental interaction—organisms are open systems that exchange materials and
energy with surroundings
vi. Energy & Life—every organism does work, which requires energy
vii. Regulation—feedback maintains homeostasis and enhances activity when necessary
viii. Unity and diversity—all organisms are related, yet over time have changed increasingly
ix. Evolution—the Darwinian theory of natural selection says that adaptations over time
have led to current life
x. Scientific inquiry—observations lead to discovery and testing explanations through
hypotheses and experiments
xi. Science, technology, and society—many technologies can apply to science; the
relationships of science and technology to society are more crucial now than ever
Chapter 2- Vivian
Chapter 2 Chemical Context of Life
1. Describe the structure of an atom.
2012 Final Review
 The atomic number of an atom is the number of protons found in the nucleus of that atom.
 The atomic mass of an atom is the sum of the protons and neutrons in that atom when it is at rest. You get
the atomic mass by adding the number of protons and neutrons together.
 The equation for finding the number of neutrons in an atom is:
N=M–n
N = number of Neutrons
M = atomic Mass
n = atomic number
 Atomic Charge is the charge of an atom. A normal atom has a neutral charge in where the number of
electrons is equal to the atomic number, but an ion is an atom that with extra or missing electrons. When
you are missing an electron you have a positive charge, when you have extra electrons you have a negative
charge.
 The outermost shell of an atom is called its Valence shell. The electrons of only this outermost shell are
involved during chemical combinations; electrons are either given out from the outermost shell, or accepted
into the outermost shell, or shared with the electrons in the outermost shell of another element.
 Elements having same number of valence electrons in their atoms possess similar chemical properties. All
alkali metals have one valence electron in their atom. Thus, their chemical properties are similar.
 The number of the valence shell in an atom determines its position in the Periodic Table i.e. the period to
which the element belongs.
Elements having 1, 2 or 3 electrons in the valence shell are metals. Exception is H and He. Elements having 4 to 7
electrons in their valence shell are non-metals.
 Radioactive tracers also known as radio active isotopes are used to identify and treat diseases. These
Isotopes can be used to detect the exact position of a blood clot or tumor in the human body once
introduced into the system. These tracers can also be used to study the movement of ions across the
membrane. They are even used in carbon dating to find the age of old living things.
Chemical Context of Life- Jared Davis
Question 2: Explain the different types of bonds between atoms. Give an example of each. Then rank them from
strongest to weakest.



Covalent (polar versus nonpolar)
A covalent bond is the sharing of a pair of valence electrons by two atoms.
A nonpolar covalent bond is a bond in which the electrons are equally shared (occurs when the atoms
in the bond are equally electronegative - the attraction of an atom for the electrons of a covalent
bond.) for example: a bond between two oxygen molecules.
A Polar Covalent bond is one in which the electrons are not shared equally. A water molecule is an
example of a molecule bonded through a Polar Covalent bond.
Ionic
A charged atom (or molecule) is called an ion.
A positively charged ion is called a cation, while a negatively charged ion is called an anion.
An Ionic Bond is a chemical bond resulting from the attraction between oppositely charged ions.
Salts are compounds formed by ionic bonds and are called Ionic Compounds.
Hydrogen
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-

A Hydrogen Bond a type of weak chemical bond formed when the slightly positive hydrogen atom of
a polar covalent bond in one molecule is attracted to the slightly negative atom of a polar covalent
bond in another molecule.
Water molecules bond together through Hydrogen bonding.
Van der Waals interactions
Van der Waals Interactions – weak attractions between molecules or ports of molecules that are
brought about by localized charge fluctuations.
Vad der waals Interactions also play a role in the bonding between water molecules.
Strength Ranking
1.
2.
3.
4.
Covalent bonds
Ionic bonds
Hydrogen Bond
Van der Waals Interactions
Chapter 3- William Tarte
Water and the Fitness of the Environment
1. Water is H2O the two hydrogens bond with the oxygen on top if the molecules kind of like ears. This molar
structure gives the molecule polarity which attracts other atoms to it. One side has a positive charge and the other is
negative and it attracts its opposites. This is what makes water so unique.
• it's polar structure: it is polar because the two hydrogens are on top and the oxygen is on bottom which makes it so
the top of the water molecule has a positive charge and the bottom is negatively charged making it polar.
• Ability to Ron H-bonds: hydrogen bonds happen when hydrogen atoms are attracted to a negatively charged atom.
Normally it bonds with oxygen and nitrogen.
•Cohesive properties: cohesion is hen water is attracted to water. In liquid form the hydrogen bond is weak so it
keeps forming and breaking bonds, but these bonds are what hold the water together
•Adhesive bonds: adhesion is the clinging of one substance to another. When water evaporates from leaves it pulls
up the other water molecules this kind of counteracts the pull of gravity.
2.
3. a. Be very specific in defining what the pH scale is in terms of hydrogen and hydroxide ions.
In a solution there is a certain concentration of hydrogen ions and hydroxide ions produced from the
splitting of water. When this concentration of hydrogen ions and hydroxide ions are the same then the pH of the
solution are 7 and neutral. As the concentration of hydrogen ions increases the pH goes up and becomes for acidic.
As the hydroxide ions concentration increase the pH goes down and becomes more basic.
b. How do buffers minimize changes in pH? Give an example:
A buffer acts as a donor or acceptor of hydrogen ions. For example if an acidic solution is added to a buffer
solution then the buffer will accept hydrogen ions and make the solution more basic. The same is for a basic solution
only hydrogen ions are donated to make the solution acidic. An example of a buffer is ethanoic acid and sodium
ethanoate.
2012 Final Review
4. Describe the causes and effects of acid precipitation,
Acid precipitation is caused by the burning of fossil fuels and the gasses they release mixing with water
vapor such as sulfur dioxide. This turns into sulfuric and nitric acid which falls as acid rain causing the environment
to be weaken, sickness to spread and corrosion of buildings
Chapter 4 – Jason & Charlie
Carbon and the Molecular Diversity of Life
1. Carbon is a highly diverse atom. It can bond to all of the other major elements of life such as C, H, O, N,
and S. Due to its unique bonding structure it can bring these biologically essential elements together in a
variety of ways which allow organisms to be so wonderfully diverse.
Carbon has 6 total electrons. There are 2 in the first electron shell and 4 in the second electron
shell. That means carbon has 4 valence electrons which leaves 4 empty spots since the second shell may
contain 8 electrons. Since there are 4 valence electrons, Carbon has little tendency to gain or lose electrons
because most atoms will not take or give 4 electrons at a time. Instead of bonding with one atom carbon can
bond with four other atoms and acts as the intersection between them. This ability to bond 4 ways is called
tetravalence, which is a special characteristic of carbon that makes it so diverse when constructing
macromolecules.
Carbons are vital in forming hydrocarbons. Hydrocarbons are organic molecules that consist of
only carbon and hydrogen. In these hydrocarbons, hydrogen atoms are attached to a carbon skeleton.
Hydrocarbons cause the hydrophobic behavior of fats.
The following functional groups increase the solubility of organic compounds in water.
1. hydroxyl- In this group a hydrogen atom is bonded to an oxygen atom which is bonded to the carbon skeleton.
This group is present in alcohols.
2. carbonyl- In this group a carbon atom is joined to an oxygen atom by a double bond. If the carbonyl group is at
the end of a carbon skeleton the organic compound is called an aldehyde. If not, the organic compound with
carbonyl in it is called a ketone.
3. carboxyl- In this group an oxygen atom is bonded to a carbon atom that is bonded to a hydroxyl group. This
whole assembly of atoms is called a carboxyl group. Carboxyl groups are present in carboxylic acids (organic acids).
4. amino- In this group a nitrogen atom is bonded to two hydrogen atoms and to the carbon skeleton. Organic
compounds in this group are called amines. This group is present in glycine.
5. sulfhydryl- In this group a sulfur atom is bonded to a hydrogen atom. This group has a similar shape to that of the
hydroxyl group. Organic compounds containing sulfhydryls are called thiols.
6. phosphate- In this group a phosphate ion is covalently attached by an oxygen atom to the carbon skeleton. This
can be found in ATP.
Chapter 5- Luis
The structure and Function of Macromolecules
1. Contrast condensation (dehydration) with Hydrolysis reactions. Give an Example of each.
A similarity: both reactions occur in the human body and both reactions have to do with water.
Differences: In Dehydration reactions (Condensation), water is removed to join two molecules together.
Ex: the condensation of ethanol to form ether: 2CH3CH2OH  (CH3CH2)2O + H2O
Hydrolysis is the opposite. A water molecule is added to break apart two molecules.
Ex: Alkyl halide to alcohol : R-Cl + H2O ROH + H+ + Cl2.
Name the monomers that compose each of the following: carbohydrates, lipids, proteins and nucleic
acids.
Carbohydrates – Monosaccharides
What are isomers and can you
Lipids – glycerol and 3 fatty acid molecules
recognize from the
Proteins – Amino Acids
Nucleic Acids – Nucleotides
biomolecules which ones they
3.
Distinguish between and give examples of :
a) Monosaccharides, disaccharides and polysaccharides
are?
2012 Final Review
Monosaccharide - A monosaccharide is the simplest sugar, a sugar building block. This is
something like glucose, fructose, or galactose.
Disaccharide - If you put two monosaccharides together and let them bond, they form a
disaccharide, like maltose or sucrose or lactose.
Polysaccharide - A polysaccharide is basically a chain of monosaccharides bonded together. This
is something like cellulose.
b) Glucose and Sucrose
Glucose - Its chemical formula is C6H12O6. If this is re-written as C6(H2O)6 – it is seen that it is a
hydrate of carbon. It is a simple monosaccharide.
Sucrose - Sucrose is a disaccharide formed from glucose and fructose. It is also a carbohydrate its
formula is C12H22O11 or C12(H2O)11. The molecules are joined by loss of water to give the
disaccharide sucrose.
2012 Final Review
c) Starch, glycogen, cellulose and chitin
Starch: it is a polymer of glucose monomers. Synthesizing starch enables the plant to stockpile surplus glucose. It is
known as “stored energy” in plants.
Glycogen: a polymer of glucose, also known as “stored energy” in animals.
Cellulose: like starch, cellulose is a polymer of glucose but the glycosidic linkages in these two polymers differ.
Cell walls of plants are an example of cellulose.
Chitin: carbohydrate used by insects to build exoskeletons. Similar to cellulose except that the glucose monomer of
chitin has a nitrogen containing appendage.
d) Fatty acid and glycerol
Fatty acid : fatty acids are long chains of carbons (C16-C20) with a Carboxyl acid group at the end
which can be made up to for a larger macromolecule called triglycerides.
Glycerol: it is only a 3 carbon molecule with 3 OH groups. Its function in biology is to be the
backbone to triglycerides.
e) Saturated and Unsaturated fatty acids
2012 Final Review
Saturated fatty acids: saturated fatty acids are solid at room temperature. They are linked by
single bonds. They’re commonly known as the “bad” fatty acids.
Unsaturated fatty acids: they are liquid at room temperature and have some double bonds. The
double bond is a prominent characteristic of unsaturated fatty acid chains, as there is a “bend” in
the chain.
f) Fat and Phospholipid
Fat: made of triglycerides, where all three hydroxyl groups are attached to fatty acid chains.
Phospholipid: Like fats (triglycerides), but the third hydroxyl group of gycerol is linked to a
phosphate group instead of another fatty acid. In phospholipids, a small polar or charged nitrogencontaining molecule is attached to this phosphate. The gycerol "backbone", phosphate group, and
charged molecule constitute a polar hydrophilic region at one end of the phospholipid,
2012 Final Review
g) Polysaccharide and Polypeptide What are polysaccharides function?
Polysaccharide: a long string of sugar building blocks, forming a large, complex sugar molecule.
Polypeptide: a long chain of amino acids, forming a protein.
h) DNA and RNA
DNA: DNA (deoxyribonucleic acid) is double stranded (double helix).The two strands are
complementary to each other (G with C and A with T). DNA codes for everything, sometimes
directly, but often indirectly. It even codes for RNA.
2012 Final Review
RNA: RNA (ribonucleic acid) is single stranded. RNA is made up of base pairs (so is DNA). 3
base pairs comprise a codon, which codes for different amino acids, which make up proteins. So
with the help of ribosomes, RNA makes proteins. Also there are three types of RNA, rRNA
(ribosomal RNA) mRNA (messenger RNA) and tRNA (transfer RNA) which are complementary
to each other when making a protein, this time however the A is not complementary with T, but
instead it is complementary with U.
2012 Final Review
i) Purine and Pyrimidine
Purine: A nitrogenous base, Purines have a two ring structure and it is the bigger of the two. The
Purines in DNA are Adenine and Guanine. In RNA, the purines are the same as DNA.
Pyrimidine: A nitrogenous base, Pyrimidine is a one ring structure, smaller than purine. In DNA,
the Pyrimidines are thymine and cytosine, while in RNA they are Uracil and Cytosine. Uracil is
the RNA substitute for Thymine.
2012 Final Review
j) Nucleoside, Nucleotide and Nucleic Acid
Nucleoside: Any of various compounds consisting of a sugar, usually ribose or deoxyribose, and a
purine or pyrimidine base, especially a compound obtained by hydrolysis of a nucleic acid, such as
adenosine or guanine.
Nucleotide: Any of various compounds consisting of a nucleoside combined with a phosphate
group and forming the basic constituent of DNA and RNA.
Nucleic Acid: Any of a group of complex compounds found in all living cells and viruses,
composed of purines, pyrimidines, carbohydrates, and phosphoric acid. Nucleic acids in the form
of DNA and RNA control cellular function and heredity.
2012 Final Review
Know these vocab words:
a.
b.
c.
d.
e.
Hydrogen bond
Peptide bond
Glycosidic bond
Ester bond
Amino Group
Chapter 5, 4-7 - Miguel
4. Describe the structure, characteristics and functions of carbs
Carbohydrates are organic compounds made up only of Carbon, Hydrogen, and Oxygen. Carbohydrates are
also known as saccharides, and are divided into 4 groups: monsaccharides (simple sugars like glucose and fructose),
disaccharides (sucrose, lactose), oligosaccharides (like a polysaccharide, but fewer sugars), and polysaccharides
(long chains of monomer sugar units). Polysaccharides are used to store energy in organisms. The monosaccharide
ribose is an important part of RNA, and coenzymes like ATP.
5. Describe the structure, characteristics and functions of lipids
Lipids are a group of molecules that includes fats, waxes, sterols, fat-soluble vitamins, monoglycerides,
diglycerides, triglycerides, phospholipids, and others. Their main purposes are to store energy, and to act as
structural components of the cellular membrane and signaling molecules. Lipids consist of a hydrophilic head and a
hydrophobic tail (hydrocarbon chain).
6. Describe the structure of an amino acid. What is a protein? In a diagram, label the carboxyl and amino groups.
then, show a condensation reaction between two amino acids and circle the peptidew bond that forms in between
them
Know the monomer and polymer
unit of all biomolecules.
a)
< Carboxyl Group
^Amino Side Chain
2012 Final Review
b) describe the four structural levels in the conformation of a protein
Primary sturcture is the order of amino acids in a protein
Secondary structure is how the order folds in order to form Alpha-Helices, or Beta-Pleated sheets
Tertiary Structure is how many Beta-pleated sheets, and Alpha-Helices fold to form a complete protein, and
within it are identified regions called Domains and Motifs
Quaternary Structure is how whole proteins interact with eachother
c) what does denaturation mean? What causes it? What is the result of it?
Denaturation is when lipids or amino acids lose their tertiary and secondary stuructures as a result of some
external influence, like a strong acid or base, an organic solute like alcohol, or energy. This disrupts cell
activity and could lead to cell death.
d) . Describe at least four different types of proteins, explain their functions and name examples.
Enzymes - proteins that catalyze chemical and biochemical reactions within living cell
e.g. DNA polymerase
Hormones - proteins that are responsible for the regulation of many processes in organisms. E.g. insulin,
prolactin
Transport proteins - These proteins are transporting or store some other chemical compounds and ions. E.g.
haemoglobin and myoglobin
Structural proteins - These proteins are maintain structures of other biological components, like cells and
tissues. E.g. Collagen, elastin, α-keratin, sklerotin, fibroin
7. Describe the structure, characteristics and functions of nucleic acids
Nucleic acids are large biological molecules, consisting of DNA (deoxyribonucleic acid) and RNA
(ribonucleic acid). Nucleic acids are used to transfer genetic material from one generation of cells to the next. They
consist of a nitrogenous base, a five-carbon sugar, and a phosphate group. DNA more or less contains the
programmatic instructions for all cellular activities.
Chapter 6- A Tour of the Cell
1. The cell is the unit of structure and function of all organisms. Name the four structures found in ALL
cells.
 DNA- the genetic material contained in one or more chromosomes and located in a nonmembrane
bound nucleoid region in prokaryotes and a membrane-bound nucleus in eukaryotes.
 Plasma Membrane- A phospholipid bilayer with proteins that separates the cell from the
surrounding environment and functions as a selective barrier for the import and export materials
 Cytoplasm- The rest of the material of the cell within the plasma membrane, excluding the
nucleoid region or nucleus, that consists of a fluid portion called the cytosol and the organelles and
other particulates suspend in it.
 Ribosomes- The organelles on which protein synthesis takes place
2012 Final Review
2.
3.
4.
A) Describe the differences that separate prokaryotic from eukaryotic cells
 Eukaryotic cells have a nucleus bound by a double membrane; prokaryotic cells do not have a
nucleus.
 Eukaryotic cells contain many chromosomes; Prokaryotic cells have one circular DNA molecule
and many smaller circlets of DNA called plasmids.
 The cytoplasm of eukaryotic cells is filled with many complex organelles, many of them enclosed
by their own membranes; Prokaryotic cells contain no membrane-bound organelles which are
independent of the plasma membrane
 There is much more space within Eukaryotic cells than in prokaryotic cells due to the vast number
of organelles
 Eukaryotic cells are found in multi-cellular organisms; Prokaryotic cells are in uni-cellular
organisms.
B) Give examples of prokaryotic and eukaryotic cells
 Prokaryotic- Bacteria, Archaebacteria
 Eukaryotic- Animal cells, plant cells, protozoa, fungi
Explain the importance of cells being microscopic in size
 Cells need to be able to exchange and dispose of materials; if the cell was large, cellular functions
would not be able to occur as quickly
Distinguish between the following pairs of structures in BOTH their structure AND function.
A) Cell membrane and cell wall
 The cell membrane is found in most all cells while cell walls are present in plant cells, fungi,
bacteria, and algae, not animal cells or protozoa
 The cell membrane is semi permeable and separates the components inside the cell from the
outside. The cell membrane provides support to the cytoskeleton of the cell and helps in cellular
communication.
 The cell wall provides strength and rigidity to the cell and protects the cell against mechanical
forces. Also helps in retaining water in the cell.
B) Nucleus and Nucleolus
 The nucleus is a membrane-bound organelle surrounded by a double membrane.
Communicates with surrounding cytosol via numerous nuclear pores; Within the nucleus is
DNA which provides the cell with its unique characteristics.
 The nucleolus is the prominent structure found in the nucleus; produces ribosomes which
move out of the nucleus to position on the rough endoplasmic reticulum where they are vital
in protein synthesis.
C) Rough endoplasmic reticulum and smooth endoplasmic reticulum
 The rough endoplasmic reticulum appears rough because of the ribosomes that bound to the
cytosolic side of it; the presence of the ribosomes indicates that the rough e.r. is involved in
protein synthesis.
 The smooth e.r. has no bound ribosomes and is not involved in protein synthesis; involved in
cholesterol metabolism, membrane synthesis, and detoxification.
D) Lysosomes and peroxisomes
 Lysosomes fuse with food vacuoles and membranous vesicles; contain hydrolytic enzymes for
digestion; digests macromolecules; breaks down damaged organelles; and is built with
proteins from the rough ER; Lysosomes function within the context of the endomembrane
system.
 Peroxisomes break down substances via oxidation; detoxify; break down fatty acids; built
with proteins from ribosomes in the cytosol; do not bud off the endomembrane system.
E) Food vacuole, contractile vacuole, and central vacuole
 Food vacuole is a membrane-bound vacuole where ingested food is stored and digested; food
contained within the vacuole is taken up by phagocytosis
 Sub-cellular organelle involved in osmoregulation; expels excess water out of the cell by
contracting
 The central vacuole is bound by a single membrane and contains water, food, and metabolic
waste; maintains turgor pressure against the cell wall
F) Chloroplast and mitochondria
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
Mitochondria- The powerhouse of the cell; convert energy to forms that are useful in the cell;
located in the cytoplasm and are the sites of cellular respiration, cell division and growth, and
cell death. Bound by a double-membrane and each membrane is a phospholipid bilayer
embedded with proteins. Breaks down nutrients and sugars the cell receives for energy
 Chloroplasts- food producers of the cell; found in plant cells; create sugars and oxygen; the
stroma is inside the chloroplast where the reactions occur and the sugars are created; one
thylakoid stack is called a granum and thylakoids have chlorophyll molecules on their surface.
G) Mitochondrial Matrix and cristae
 Mitochondrial Matrix-contains soluble enzymes that catalyze the oxidation of pyruvate and
other small organic molecules; contains mitochondria’s DNA and ribosomes; Citric Acid
(Krebs) cycle takes place within Mitochondrial Matrix
 Cristae-internal compartments formed by the inner membrane of a mitochondrion; studded
with proteins; increases the surface area for chemical reactions to occur (ex: cellular
respiration)
H) Chloroplast Thylakoids (grana) and Stroma
 Grana- stacks of thylakoids; act to trap the energy from sunlight; thylakoid membrane
contains chlorophyll
 Stroma- the fluid between the grana; carbohydrate-formation reactions occur in the
chloroplast of plant cells photosynthesizing
I) Cilia and Flagella
 Cilia- microscopic, hair-like structures (organelles) extending from the surface of almost all
mammalian cells; motile cilia are found in lungs, respiratory tract, and middle ear; they keep
airways clear of mucus and dirt; primary cilia act as signal antenna for the cell, receiving
signals from other cells or fluids nearby; found in eukaryotic cells
 Flagella- longer than cilia; found in prokaryotic and eukaryotic cells; tail-like propeller on
some cells that allow the cell to move; located on the outer wall of the cell and main function
is movement
J) Basal body and Centriole
 Basal Body- modified centrioles that give rise to cilia and flagella; complex structure that can
form through at least two distinct pathways; contains a large number of proteins
 Centriole- every animal-like cell contains two; help the cell when it divides; small set of
microtubules (9 groups); found near the nucleus; when the cell is about to divide, they move to
opposite ends of the nucleus; one pair of centrioles moves in each direction; usually found in pairs
of 2
Chapter 6, questions 5-8 Mariana
5. Ribosomes- main function is protein synthesis, they are located in the cytoplasm or physically attached to the
endoplasmic reticulum.
Endoplasmic Reticulum- functions as a packaging system, and creates networks of membranes found throughout the
cell. There are two types of ER’s, smooth and rough. The smooth ER acts a storage organelle and stores steroids and
ions that the cell may need later on. The rough ER works with ribosomes. The ribosomes are attached to the
membrane of the ER and they build amino acid chains and when the protein is complete, the ER pinches off a
vesicle that can either go to the cell membrane or the Golgi apparatus.
Golgi Apparatus- is another type of packaging system. It takes simple molecules and combines them into more
complex molecules that are packaged into vesicles that either store them for later use or are sent out of the cell. The
Golgi apparatus works closely with the ER. When proteins in the ER are made, they come to the Golgi thru a
transition vesicle and after the golgi has done its work a secretory vesicle is made and released, the vesicle then goes
to the cell membrane and the molecules are released out of the cell.
6. The cytoskeleton has many functions, is helps create the cell shape, helps with internal movement of cell
organelles as well as locomotion and muscle fiber contraction. The cytoskeleton includes three primary protein
filaments: microfilaments (actin filaments), intermediate filaments and microtubules. Microfilaments are the
2012 Final Review
thinnest filaments (6 nanometers in diameter) of the cytoskeleton, its structure is a double helix, and it’s composed
of linear polymers of actin subunits. They generate force by elongation at one end of the filament coupled with
shrinkage at the other, causing net moving of the intervening strand. Intermediate filaments are about 10 nm in
diameter and are more stable than microfilaments, its structure is two anti-parallel helices/dimers that form
tetramers, but like microfilaments they also help with the cell shape by bearing tension. Intermediate filaments also
organize the internal tridimensional structure of the cell. Different intermediate filaments are composed of vimentin,
keratin, nuclear lamins and neurofilaments. Microtubules are hollow cylinders about 23 nm in diameter, it’s
structured by protofilaments, and unlike micro and intermediate filaments they resist compression to help structure
the cell shape. Microtubules form the cilia and flagella which are both structural components of the cell.
7. Structural differences between animal and plant cells: animal cells don’t have a cell wall while plant cells have
walls formed of cellulose. Animal cell shapes are round and irregular while plant cells are rectangular. Animal cells
have one or more vacuoles that are smaller than the ones found in plant cells, and plant cells have one large vacuole.
Plant cells contain chloroplasts because they make their own food, animals don’t. Cytoplasm, Mitochondria’s,
ER’s, Golgi Apparatus, Nucleus, Microfilaments/Microtubules, and Ribosomes are found in both animal and
plant cells. Flagella’s might be found in some animal and plant cells.
8. There are three intercellular junctions found in both plant and animal cells:
Tight junctions- bind cells together so that nothing can pass through the intercellular spaces.
Desmosomes- bind cells together like rivets, they allow material to pass through intercellular space.
Gap junctions- they connect cells but allow material to pass from one cell to the other through the opening in the
center of the joint. These are analogous to the plasmodesmata in plants.
Chapter 7 (Membrane Structure and Function) – Ariana
1. Cell membranes are composed of lipids, proteins, and carbohydrates. The must abundant lipids in the membrane
are phospholipids. A phospholipid is an amphipatic molecule, meaning it has both a hydrophillic region and a
hydrophobic region.
Proteins have six major functions which are: transport, enzymatic activity,signal transduction,intercelluar joining,
cell-cell recognition, adn attachement to the cytoskeleton and extracellular matrix.
glycolipids and glycoproteins are important in cell-cell recognition and cell-cell interaction.
Membranes are fluid due to the lateral movement of phospholipids. Membranes that have unsaturated hydrocarbon
tails have kinks that keep the molecules from packing together, enhancing membrane fluidity. Cholesterol reduces
membrane fluidity at moderate temperatures by reducing phospholipid movement, but at low temperatures it hinders
solidification by disrupting the regular packing of phospholipids.
2.The lipid bilayer and proteins cause cell membranes to be selectively permeable. The hydrophobic core of the
membrane impedes the transport of ions and polar molecules, it also doesn't allow for large molecules to pass
through. Proteins built into the membrane play key roles in regulating transport.
3. Diffusion-the movement of a substance from an area of high concentration to an area of low concentration; does
not require an energy input. (Oxygen and Carbon Dioxide)
Osmosis-the diffusion of water across a selectively permeable membrane.
facilitated diffusion-difussion that requires the use of a protein channel. (glucose to red blood cells)
4. Animal cells placed in:
hypotonic solutions will lyse(burst).
isotonic solutions wll be in an ideal enviroment(normal).
hypertonic solutions will shrivel.
Plant cells placed in:
hypotonic solutions will become turgid.
isotonic solutions will become flaccid.
hypertonic solutions will become plasmolyzed.
5. a. Contrast exocytosis and endocytosis. Give an example of each.
Exocytosis is a form of transport wherein a cell packages a substance(such as waste products) in a vesticle
and has the vesticle fuse with the cell membrane, ejecting the target from the cell. Endocytosis does the opposite,
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taking some desired object outside of the cell, wrapping it with the membrane and separating that part of the
membrane from the rest, bringing it into the cell as a vesticle.
b. Contrast phagocytosis, pinocytosis, and receptor-mediated endocytosis. Give examples of each.
Phagocytosis is where the cell membrane stretches out to engulf the desired substance(like food) into the cell.
Pinocytosis has the object (like extracellular fluid) kind of falling into a pit where it’s “gulped” into the cell, and
receptor mediated endocytosis is when a substance such as LCL binds to ligands on the cell membrane, which
proceed to become packaged like the other forms of endocytosis.
6. a. Explain and give examples of proton pumps in plant cell membranes.
Proton pumps are proteins that force Hydrogen Ions across the cell membrane. An example would be Complex
I that helps perform such operations in photosynthesis.
b. Relate water movement across plant cell membranes to water potential, solute(or osmotic) potential and
pressure potential.
Because cells tend to be hypertonic to their surroundings, water tends to move into them due to their higher
solute potential, but with plant cells the water potential is less than that of animal cells due to their cell walls
providing pressure potential that increases their total membrane potential, allowing them to reach equilibrium
faster.
7. a. Under what environmental conditions would a plant cell become:
i. Turgid?
When the plant cell is placed in a solution that is hypotonic compared to it
ii. Flaccid?
When the cell is in an isotonic solution, it becomes flaccid
iii. Plasmolysed?
When the cell is placed in a solution that is hypertonic compared to the cell it becomes plasmolysed
b. Explain the role of aquaporins in water transport.
Aquaporins regulate the flow of water into a cell by either allowing it (water) easy access into a cell or forcing
the H2O to trying passing through the cell membrane.
Chapter 8- Javan
2. Explain the first and second laws of thermodynamics.
The study of the energy transformations that occur in a collection of matter is called thermodynamics.
According to the first law of thermodynamics, the energy of the universe is constant. Energy can be
transferred and transformed, but it cannot be created or destroyed. The second law of thermodynamics is as
follows: Every energy transfer of transformation increases the entropy of the universe.
4. a. Describe the structure of ATP.
ATP (adenosine triphosphate) has the nitrogenous base adenine bonded to ribose, as in an adenine nucleotide
of RNA. In RNA, however, only one phosphate group is attached to the ribose, whereas adenosine
triphosphate has a chain of three phophate groups attached to the ribose.
b. Is a reaction that forms ATP exergonic or endergonic?
The bonds between phosphate groups of ATP’s tail can be broken by hydrolysis. When the terminal
phosphate bonds is broken, a molecule of inorganic phosphate leaves the ATP, which becomes adenosine
diphosphate, or ADP. The reaction is exergonic and under laboratory conditions releases 7.3 kcal of energy
per mole of ATP hydrolyzed.
c. How does ATP perform work?
With the help of specific enzymes, the cell is able to couple the energy of ATP hydrolysis directly to
endergonic processes by transferring a phosphate group from ATP to some other molecule. The recipient of
the phosphate group is then said to be phosphorylated.
5. a. Distinguish between a catalyst and an enzyme.
A catalyst is a chemical agent that changes the rate of a reaction without being consumed by the reaction; an
ensyme is a catalytic protein.
b. Explain how enzymes speed up chemical reactions.
You need to look at a graph
with the introduction of an
enzyme to lower activation
energy
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An enzyme speed a reaction by lowering the free energy of activation barrier, so that the precipice of the
transition state is within reach even at moderate temperatures.
c. Define: substrate, active site, induced fit, cofactors, and coenzymes.
The reactant an enzyme acts on is referred to as the ensyme’s substrate. Only a restricted region of the
enzyme molecule actually binds to the substrate. This region, called the active site, is typically a pocket or
groove on the surface of the protein. As the substrate enters the active site, it induces the enzyme to change its
shape slightly so that the active site fits even more snugly around the substrate. This induced fit is like a
clasping handshake. Induced fit brings chemical groups of the active site into positions that enhance their
ability to catalyze the chemical reaction. Many enzymes require nonprotein helpers for catalytic activity.
These adjuncts, called cofactors, may be bound tightly to the active siteas permanent residents, or they may
bind loosely and reversibly along with the substrate. If the cofactor is an organic molecule, it is more
specifically called a coenzyme.
d. How does the specificity of an enzyme depend on its structure.
Some reversible inhibitors resemble the normal substrate molecule and compete for admission into the active
site. These mimcs, called competitive inhibitors, reduce the productivity of enzymes by blocking substrates
from entering active sites. So-called noncompetitive inhibitors do not directly compete with the substrate at
the active site. Instead, they impede enzymatic reactions by binding to another part of the enzyme.
Section 8- Liz Gulley
1. Distinguish between catabolic and anabolic pathways. Explain the role of energy in each of these pathways.
Catabolic pathways are reactions that result in the breakdown of complex molecules into smaller molecules.
Anabolic pathways take smaller molecules and build more complex molecules. Energy is stored in anabolic
pathways. Energy in catabolic pathways is used to fuel anabolic reactions. The energy used for the chemical
reactions is stored in ATP.
3. What is free energy? Explain how ΔG derived. Explain the relationship between ΔG and whether a
reaction is exergonic and endergonic.
Free energy is the portion of a system's energy that can perform work when temperature and pressure are uniform
throughout the system. A reaction with a negative ΔG is exergonic. A positive ΔG is endergonic.
5e. How is the activity of an enzyme affected by: Substrate concentration? Competitive versus noncompetitive
inhibitors? Temperature? pH?
The higher the substrate concentration, the more activity there will be in an enzyme. The enzyme activity will not
increase infinitely because once enough substrate is added to where all the enzymes are being used to their full
potential, the activity will stop. Competitive inhibitors will cause enzymes to do more work because they are having
to compete whereas a noncompetitive inhibitor will leave the enzyme alone. Temperature and pH will affect the
activity of an enzyme because enzymes have an optimal temp and pH that they can function in.
5f. Name the bonds that are disrupted when a protein is denatured. Refer to the four structural levels in the
conformation of a protein.
Hydrogen bonds and S-S bonds are broken or weakened when a protein is denatured. Hydrogen bonds are disrupted
when there is a change in temperature. S-S bonds are disrupted when reducing agents are present. Peptide bonds are
not broken so the protein will keep its primary structure. The secondary structure occurs when the chains of amino
acids attract to each other with hydrogen bonds. If the hydrogen bonds are disrupted then the secondary structure
will be messed up. The tertiary and quaternary structures depend on the secondary structure being correct so when
the bonds are disrupted, the whole process is disrupted.
Ch. 9 Cellular Respiration – Emily & Michelle
1.
Explain what is meant by oxidation and reduction. How are the two reactions coupled together?
When a substance is reduced, is energy stored or released from it? What about when a substance is
oxidized?
Oxidation is when a molecule loses an electron, and reduction is when it gains one. Remember this by OIL RIG:
Oxidation Is Losing, Reduction Is Gaining.
Locations of the steps of C. R.
and P.
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Sometimes, when one molecule loses an electron, another molecule picks it up. Also, in a chemical equation, the
electrons on both sides have to be balanced, so if one molecule is oxidized, another has to be reduced.
When a substance is reduced, energy is stored. When a substance is oxidized, energy is released.
2.
Write the equation for cellular respiration. Name the substances that are oxidized.
Glucose is oxidized and oxygen is reduced.
3.
Describe the basic chemical processes of glycolysis. What molecules are required and what molecules
are produced by the end of the chemical pathway? How many molecules of NADH and of ATP are
produced per molecule of glucose? Where in the cell does glycolysis occur?
Glycolysis is the sequence of reactions that converts glucose into two pyruvates to be used in the Krebs cycle, and
also produces 4ATP from a 2ATP investment. It is thought to have been the first metabolic pathway that evolved
because it does not need oxygen to function, and without oxygen it goes into fermentation.
Required: glucose (or an organic molecule: fats, proteins, or carbohydrates), 2ATP, and 2NAD+
Produced: 2pyruvates, 4ATP, and 2NADH
2NADH and 2 net ATP are produced
Glycolysis occurs in the cytosol of the cell
4.
Summarize the citric acid (Krebs) cycle. What molecules enter the cycle and what molecules are
produced by the end of the cycle? How many molecules of ATP, FADH2, NADH,and CO2 are
produced per molecule of glucose? Where in the cell does the citric acid cycle occur?
The cycle begins with the reaction between acetyl-CoA and the four-carbon oxaloacetate to form six-carbon citric
acid. Through the next steps of the cycle, two of the six carbons of the citric acid leave as carbon dioxide to
ultimately yield the four carbon product, oxaloacetate, which is used again in the first step of the next cycle. During
the eight reactions that take place, for every molecule of acetyl-CoA the cycle produces three NADH and one
FADH2, along with one molecule of ATP.
Reactants: ADP+P, NAD+, FAD, acetyl CoA
Products (per pyruvate): 1ATP, 3NADH, 1FADH2, and 2CO2 per pyruvate.
This occurs in the mitochondrial matrix.
5.
Describe the critical role of NAD+ and FAD in the glycolytic and citric acid pathway.
In the citric acid pathway, NAD+ and FAD work as electron acceptors and carriers, and in the glycolytic pathway,
NAD+ is an electron acceptor. They will eventually be used in the electron transport chain to make more ATP.
6.
Explain the importance of chemiosmosis. What is the maximum number of ATP generated per
NADH and per FADH2 during chemiosmosis? Where does chemiosmosis occur whithin a
mitochondrion? Relate chemiosmosis to the electron transport chain. Where is the electron transport
chain (ETC) within a mitochondrion?
Chemiosmosis is the diffusion of ions across a selectively-permeable membrane. More specifically, it relates to the
generation of ATP by the movement of hydrogen ions across a membrane during cellular respiration.
Maximum number of ATP generated: 3 per NADH, 2 per FADH2
Chemiosmosis occurs across the inner membrane of a mitochondria.
After an ion gradient is created across the membrane with the ETC, there is potential energy that can be used to
generate ATP, and with chemiosmosis, the energy is harvested by the ATPase to make ATP.
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7.
Contrast the number of ATP generated per glucose during oxidative phosphorylation with the
number generated during substrate-level phosphorylation.
About 34ATP is generated per glucose with oxidated phosphorylation (electron transport chain), and about 4 is
generated with substrate-level phosphorylation (glycolysis and Krebs cycle). A lot more ATP is generated with
oxidative phosphorylation.
8. How do cells generate ATP in the absence of oxygen? Describe two different fermentation pathways.
Without oxygen, glycolysis still produces 2ATP, and then it goes into an anaerobic process called fermentation.
Fermentation provides a way to regenerate NAD+ to be reused in glycolysis to create more ATP anaerobically. The
two different fermentation pathways are alcoholic fermentation and lactic acid fermentation.
9.
Compare the number of ATP produce from the metabolism of one glucose molecule under aerobic
conditions with the number produced under anaerobic conditions. Which is more energy efficient?
Two molecules of ATP produced under anaerobic condition, and 38 molecules of ATP are produced under aerobic
conditions. Aerobic respiration is more energy efficient.
10. Explain how each of the organic molecules of fats, proteins, and carbohydrates enter the reactions of
cellular respiration.
Carbohydrates are metabolized to acetyl-CoA via glycolysis and went to the citric acid cycle.
Proteins are metabolized by a variety of pathways. Most go to oxaloacetate or other intermediates in the citric acid
cycle. Because of the diversity of amino acids, they feed numerous catabolic and anabolic pathways with many
different intermediates.
Fats oxidized to acetyl CoA as well, and went to the citric acid cycle.
Chapter 10 Ashley
1. Distinguish between grana, thylakoids, and stroma in their structure and function.
Grana- Grana is the plural of granum. A granum is a stack of thylakoids found in chloroplast. Grana are multiple
stacks of thylakoids found in chloroplasts in the cell. The light reaction of photosynthesis takes place in the
thylakoids staked in Grana
Thylakoid- A flattened membrane sac inside the chloroplast, used to convert light energy to chemical energy.
Stroma- The fluid of the chloroplast surrounding the thylakoid membrane; involved in the synthesis of organic
molecules from carbon dioxide and water.
2. Write the equation for photosynthesis. Name those molecules that are oxidized and those that are reduced. What
molecules are split to release oxygen gas? What is phosphorylation? What is carbon fixation?
6CO2 +6 H2O + Light Energy -> C6H12O6 + 6O2
Carbon atoms are reduced making glucose and water (H2O) is oxidized making O2.
Phosphorylation- the addition of a phosphate (PO4) group to a protein or other organic molecule.
Carbon Fixation- The incorporation of carbon from CO2 into an organic compound by an autotrophic organism (a
plant, another photosynthetic organism, or a chemoautotrophic bacterium)
3. Contrast the major events that occur during the light reactions with those that occur during the Calvin cycle.
Photosynthesis depends on an interaction between two sets of reactions: the light reactions and the Calvin cycle.
Chlorophyll and the other molecules responsible for the light reactions are built into the thylakoid membranes. The
enzymes that catalyze the Calvin cycle are located in the stroma. Beginning with the absorption of light by
chlorophyll, the light reactions convert light energy into chemical energy in the form of ATP and NADPH. The ATP
provides the energy, and the NADPH supplies the electrons for the Calvin cycle, which converts carbon dioxide to
sugar. The ADP and NADP+ that result from the Calvin cycle shuttle back to the light reactions, which regenerate
ATP and NADPH.
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4. Explain the difference between absorption and action spectra. What conclusions can be drawn from each?
Absorption Spectrum- The rage of a pigment’s ability to absorb various wavelengths of light
Action Spectrum- A profile of the relative performance of different wavelengths of light.
5. The light-dependent reactions: What do you need in order for photosystem II to occur?
a. What forms the reaction center in a photosystem? Chlorophyll a
b. Contrast photosystem I and photosystem II.
Photosystem I occurs after photosystem II and uses the P700 reaction-center chlorophyll.
Photosystem II occurs before photosystem I and uses the P680 reaction-center chlorophyll.
c. Contrast cyclic and non-cyclic electron flow.
Cyclic electron flow: (involves only photosystem I)
sugar synthesis uses more ATP than NADPH, if there is already suffcient NADPH,
-photosystem I is excited by light absorption
-the e- is donated to electron transport (H+ pumping & ATP synthesis)
-e- are "cycled" back to photosystem I
(this e- path produces only ATP for sugar synthesis)
Noncyclic electron flow: begins in photosystem II:
-photosystem II is excited by light absorption
-e- derived from splitting water
-the e- is donated to electron transport (H+ pumping & ATP synthesis)
-the e- is passed on to photosystem I
-photosystem I is excited by light absorption
-the e- is used to reduce NADP
(this e- path produces ATP and NADPH for sugar synthesis)
6. Contrast the chemiosmotic mechanism for ATP formation in the mitochondrion to that in the chloroplast.
In both kinds of organelles (Mitochondrion and chloroplast), electron transport chains pump protons (H+) across the
membrane from a region of low H+ concentration to one of high H+ concentration. The protons then diffuse back
across the membrane through ATP synthase, driving the synthesis of ATP.
Aaron
7. How is the Calvin Cycle dependent on the light reactions? Name the enzyme that “fixes” CO2? What substances
are supplied to the light reactions from the Calvin Cycle?
-The Calvin Cycle needs the ATP and NADH that the light reactions produce supplying energy and electrons
respectively to convert carbon dioxide into sugar resulting in ADP and NADP+ to the light reactions to continue to
make ATP and NADPH.
-The enzyme that “fixes CO2 is rubisco.
8. What is photorespiration? When does it occur? How is it a disadvantage to plants?
-Photorespiration is the process of metabolic pathway that consumes oxygen, releases carbon dioxide, generates no
ATP, and decreases photosynthetic output. Generally occurs on hot, dry, bright days, when stomata close and the
oxygen concentration in the leaf exceeds that of carbon dioxide. Occurs when Rubisco can utilize O2 as a substrate
instead of Co2. The stomata will partially in this weather. When the O2:CO2 ratio increases, there is not enough
CO2 and Rubisco. It is a disadvantage because photorespiration consumes O2 and organic fuel releasing CO2
without producing ATP or sugar.
9. Contrast C3 and C4 plants. Name examples of each and describe the environments in which they normally live.
Contrast the internal anatomy of the leaves. Explain the role of PEP carboxylase in C4 plants.
-C3 are named so because the CO2 is first incorporated into a 3-carbon compound. Their stomata are open during
the day and the Rubisco is involved with the uptake of CO2. Photosynthesis takes place throughout the leaf and is
more efficient than C4 and CAM plants. Most plants are C3 plants, live in cool, moist conditions with normal light
having no distinct bundle sheath as leaf anatomy. Ex: grapes, wheat, and potatoes.
- C4 plants are named so because CO2 is first incorporated into a 4-carbon compound. The stomata are open during
the day and it uses PEP Coboxylase for the enzyme involved in the uptake of CO2. This enzyme allows CO2 to be
taken into the plant very quickly, and it then “delivers” the CO2 directly to Rubisco for photosynthesis. These
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plants live under high light intensity and high temperatures. The anatomy of these plants is called Kranz Anatomy
where photosynthesis occurs in the inner cells. Ex: Corn, sugarcane, crabgrass.
10.How are CAM plants adapted for surviving in hot, dry environments? Name some CAM plants. Contrast C4 with
CAM photosynthesis.
-CAM plants have adapted to surviving hot, dry environments by storing CO2 in the form of an acid before use in
photosynthesis. Where the stomata open at night, when evaporation rates are lower, and close during the day. Then
CO2 is converted into an acid and stored during the night while, during the day, the acid is broken down and the
CO2 is released to Rubisco to preform photosynthesis.
Ex: pineapples and cacti
- CAM and C4 plants both live in hot, dry environments but CAM plants experience more extreme weather
with little rain needing their stomata to open during the night.
11. Compare aerobic respiration and photosynthesis in eukaryotic cells. Specify reactants and products, electroncarrier molecules, substances that are oxidized or reduced, organelles involved, etc.
- In aerobic respiration O2 and glucose(sugar) are used to get chemical energy for the cell while photosynthesis uses
light energy and CO2 to make glucose begetting chemical energy.
Aerobic respiration occurs in the mitochondria and requires ATP, ADP, NADH, and NAD+ along with the O2 and
glucose.
C6H12O6 + 6O2 --> 6CO2 + 6H2O + ~38 ATP
Photosynthesis occurs in the chlorophyll and requires sunlight and CO2 while the chemicals working in
photosynthesis are ATP, ADP, NADP+, and NADPH.
6CO2 + 12H2O + light → C6H12O6 + 6O2 + 6H2O
Chapter 12 – Kendal Wagner
1. Chromatin- the complex of dna and proteins that makes up a eukaryotic chromosome
Chromatid- contains identical copies of the chromosome's dna molecule
Cytokinesis- the division of the cytoplasm to form two separate daughter cells immediately after mitosis
Centriole- a structure in an small cell composed of cylinders of microtubule triplets attached in a 9 + 1 pattern. An
animal cell usually has a pair of centrioles involved in cell division
Centrosomes- material present in the cytoplasm of eukaryotic cells, important during cell division; the microtubuleorganizing center.
Centromere- the centralized region joining two sister chromatids
Kinetochore- a specialized region on the centromere that links each sister chromatid to the mitotic spindle
Aster- a cellular structure shaped like a star, formed around each chromosome
2. Interphase is when the cell grows and copies its dna in preparation for mitosis which is the actual division of the
cell. DNA is synthesized during S phase (S stands for synthesize). Chromosomes are visible under the light
microscope during Prophase of mitosis because the chromatid fibers are becoming more tightly coiled
3. Prophase- chromatin is condensing. The nucleolus is still clearly present but will soon begin to disappear.
Although not yet visible, the mitotic spindle is starting to form
Prometaphase- we can see discreet chromosomes; each consists of two identical sister chromatids attached all along
their lengths. Later in prometaphase, the nuclear envelope will fragment and spindle microtubules will attach to the
kinetochores of the chromosomes
Metaphase- the spindle is complete, and the chromosomes attached to microtubules at their kinetochores are all at
the metaphase plate
Anaphase- the chromatids of each chromosome have separated, and the daughter chromosomes are moving to the
poles of the cell as their kinetochore microtubules
Telophase- daughter nuclei are forming. Meanwhile, cytokinesis has started: the cell plate, which will divide the
cytoplasm in two is growing toward the perimeter of the parent cell.
Even distribution is assisted by the microtubules acting on the chromosomes. Microtubules that do not interact with
chromosomes attach to opposite microtubules preventing any uneven distribution.
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4. In animal cell cytokinesis a cleavage furrow forms, in plant cell cytokinesis a cell wall forms from materials from
the golgi apparatus between the two daughter cells
Cellular Reproduction- Edward
4. Contrast cytokinesis in plant and animal cells. In an animal cell the cytokinesis occurs by a process known as
cleavage. It starts with a cleavage furrow, which creates a groove on the cell surface. The cleavage furrow grows
deeper until the parent cell is pinched in two different cells.
In a plant cell a cell plate forms in the middle of the cell during telophase. The plate grows until it fuses with the
membrane, which creates two separate daughter cells.
5. Describe binary fission. How is it different from mitosis that occurs in eukaryotic cells? Binary Fission:
Type of cell division that bacteria reproduce by. Bacteria do not have spindles, so the chromosome begins
replicating. They continue replicating while one copy of the origin moves to the other end of the cell. When
replication is finished the membrane starts to grow inward, resulting in two daughter cells.
6. Explain how the cell cycle is regulated. The cell cycle is driven by specific chemical signals present in the
cytoplasm. It is regulated by a cell cycle control system, a cyclically operating set of molecules in the cell that both
triggers and coordinates key events in the cell cycle. The checkpoint in the cell cycle is where stop and go- ahead
signals can regulate the cycle. These are found in the G1, G2, and M phases. Kinases give the go- ahead signals but
need to be attached to a cyclin to be active, these kinases are called cyclin- dependent kinases (CDKs). Cdks
phosphorylates substrate proteins that affect particular steps in the cell cycle.
7. Explain the abnormalities that create cancer. Unlike regular cells, cancer cells do not respond normally to the
body’s control mechanisms. One hypothesis is that they do not have the normal signals that regulate the cell cycle,
causing it to divide excessively. Another hypothesis is that the cell cycle control system itself is abnormal.
8. Contrast autosome with sex chromosome, diploid cell with haploid cell, somatic cell with gamete. Sex
chromosome determines an individual’s gender. Autosomes are all other chromosomes. Diploid cells are cells
having two sets of chromosomes. Haploid cells have a single chromosome set. Somatic cells are any cell other than
a sperm or ovum cell. Gamete cells are sperm cells and ova.
Conner
5) Binary Fission is a type of asexual reproduction in prokaryotes where a cell divides giving rise to two cells, each
having potential to grow to the size of the original cell. Difference between binary fission and mitosis is that binary
fission most commonly happens in bacteria and prokaryotes so it occurs in non-membrane bound organelles.
6) There is a family of proteins called cyclins, there is also a family of proteins called cyclin-dependent kinases or
CDKs. Each cyclin pairs with a CDK- a kinase is a protein that phosphorylates or puts of phosphate group on a
protein or other molecule. When the cyclins and CDKs complex or bind, they are activated. The activation and
degredation of various cyclins and CDKs regulate the cell cycle.
7) Cancer cells can divide without signs and they multiply very uncontrollably. While normal cells with stop divison
when they see a damage in a strand of DNA, cancer cells do not stop and continue to multiply, this causes things
such as tumors, and can cause spreading from one area to another area of the body.
8) Autosomes are somatic and homogeneous cells,which control body characters, and sex chromosomes are
sometimes not an exact pair and determine whether a person is going to be male or female. A haploid cell has one
set of chromosomes and a diploid cell has two sets of chromosomes(one from mother and one from father). Somatic
cells are body cells that multiply through mitosis and gamete are sex cells that multiply using meiosis. gametes also
have half the chromosomes of somatic cells.