Chapter 3: Cells KEY….59 points
Focus on Wellness…DID YOU KNOW? (Pages 48 and 70) 1 point each = 2 points
1.
What are phytochemicals? _ plant chemicals thought to be beneficial in offsetting cancer and heart disease risks _______________________________________________________________
2.
What are some dietary changes you could make that would increase your intake of helpful phytochemicals?
_ consume more plant foods; reduce intake of just meat-and-potato type of diets _____________
I.
A Generalized View of the Cell 1 point each = 3 points
OBJ: Name and describe the three main parts of a cell.
1.
_ plasma membrane: flexible outer layer separating cell’s internal environment from its external environment; regulates what flows in and out _________________________________________
2.
_ cytoplasm: all cellular content inside plasma membrane; excludes nucleus _________________
3.
_ nucleus: control center because it contains genes that have code for all cellular activities and structures ______________________________________________________________________
CHECKPOINT: 2 points ; 2/3 point each
1.
What are the general functions of the three main parts of a cell?
_ plasma: regulate what goes in and out ______________________________________________
_ cytoplasm: contains cytosol with dissolved solutes and suspended particles for cell use; suspends organelles within the cell __________________________________________________
_ nucleus: control center of the cell; directs all activities and structure building _______________
II.
The Plasma Membrane ¼ point each = 4 ¾ points
OBJ: Describe the structure and functions of the plasma membrane.
1.
Explain the functions of the plasma membrane.
_ sturdy flexible barrier; controls what enters and leaves; enables cells to recognize other cells as same or foreign __________________________________________________________________
2.
Describe the structure of the plasma membrane. _ phospholipids, cholesterol, and glycoproteins
3.
Name and describe the two types of glycoproteins found in the plasma membrane. _ two types: integral proteins- extend through plasma membrane, and peripheral proteins- loosely attached to interior and exterior of plasma membrane __________________________________________
4.
Selective permeability:
Lipid bilayer is permeable to: a.
_ water ____________________ b.
_ most lipid-soluble molecules _
Examples: _ fatty acids _________________
_ fat-soluble vitamins _________
_ steroids __________________
_ oxygen ___________________
_ carbon dioxide _____________
Lipid bilayer is not permeable to:
a. _ ions ____________________________
b. _ charged particles or polar molecules _
Examples: _ glucose ____________________
_ amino acids _________________
Channels are formed by _ integral proteins ______________________________________
Transporters change shape as they _
5.
Recognition: move substances from one side to other __________ a.
Receptors recognize and bind to specific molecules
Examples: _ hormones _______________________ b.
Enzymes _ speed up chemical reactions _________ c.
Cell identity markers _ identify same cells (during tissue formation) or foreign cells
(danger) _________________________________________________________________
11 ¾ points possible

III. Transport Across the Plasma Membrane ¼ point each = 2 ¼ points
OBJ: Describe the processes that transport substances across the plasma membrane.
1.
Fluids- _ ~60 _% of the average body a. Intracellular fluid- _ ICF _- _ in cytosol _
b. Extracellular fluid- _ ECF ___________
(1) _ interstitial _- _ in between cells of tissues ________________________________________
(2) _ plasma ___- _ in blood vessels _________________________________________________
(3) _ lymph ____- _ in lymphatic vessels _____________________________________________
2.
Concentration a. _ amount of solutes in solution ___________________________________________________ b. Concentration Gradient- _ difference in concentration between two areas ________________
3.
Practice: ½ point
97% H
2
O 95% H
2
O
equilibrium is reached (isotonic)
Will move high to low; water; passive transport known as osmosis until
A.
Passive Processes
1.
Diffusion: The Principle ¼ point each = 1 point a. _ high to low; no energy required __________________________________________ b. Diffusion defined:
Substance moves due to kinetic energy
-Movement from high concentration to low concentration
-Movement of more molecules in one direction is called net diffusion
-Movement ‘down the concentration gradient’
-Continues until equilibrium is reached
SIMPLE DIFFUSION
_ movement of materials through bilayer; important exchange of gases; absorption of liquids and release of some wastes: O
2
, CO
2
, N
2
, fatty acids, steroids, fat-soluble vitamins [A, D, E, and K], glycerol, small alcohols, NH
3
, H
2
O, and Urea [polar] __________
_ move materials through often gated channels (integral proteins): K + , Cl , Na + , and Ca + __
FACILITATED DIFFUSION
_ move through integral proteins; substance binds to specific transporters [these change shape]: glucose, fructose, galactose, urea, some vitamins _________________________
Figure 3.3, page 51: 1 point
1.
How does simple diffusion differ from facilitated diffusion? _ simple  substances cross membrane through lipid bilayer; facilitated  ion channels or carriers involved ______________
2.
Osmosis ¼ point each = ¾ point a. _ movement of water across a selectively permeable membrane from an area of high concentration of H
2
O to area of low concentration of H
2
O, no energy required _______ b. Practice:
Start of experiment: Semi-permeable tube (to water) contains 20% sucrose
immersed in 100% water. Arrows moving in show start of osmosis.
1.
What substance is moving into the tube? _ water_ ________________________
2.
Is it moving ‘up the concentration gradient’ or ‘down the concentration gradient’? _ ’down the concentration gradient’ __________________________
5 ½ points possible
2

At equilibrium: ¼ point each = ¾ point
1.
Which solution has increased in volume, the sucrose in the tube or the water in the beaker? _ sucrose in tube ________________________________________
2.
What is moving up the tube? _ solution of sucrose and water ______________
At start of experiment At equilibrium
Figure 3.7, page 53: 1 point
1.
Will the fluid level in the tube continue to rise until concentrations are the same in the beaker and in the tube? _ no, water concentration can never be the same because the beaker always contains 100% pure water and the tube contains a solution that is less than 100% water ______
¼ point each = 1 ½ points
c. Osmotic pressure: _ pressure exerted on membrane because solute particles cannot cross membrane; depends on concentration of solute concentration: high solute concentration = higher osmotic pressure; low solute concentration = lower osmotic pressure _____________________________
(1) Isotonic solution: _ concentration equal
(2) Hypotonic solution: _
__________________________________ concentration of water higher outside _________________
Condition of bursting red blood cells known as: _ hemolysis __________________
(3) Hypertonic solution: _ concentration of water higher inside __________________
Condition of shrinkage of red blood cells known as: _ crenation _______________
Crenation Normal Hemolysis
Figure 3.8, page 54: 1 point
Look over and study Figure 3.8 on page 54, then answer the following question:
1.
Will a 2 percent solution of NaCl cause hemolysis or crenation in red blood cells (RBCs)? Justify your answer by explaining how you derived it.
_ 2% solution of NaCl will cause crenation of RBCs because it is hypertonic; water will move out of RBCs _______________________________________________________________________
4 ¼ points possible
3

B.
Active Processes ¼ point each = 2 points
1.
Active Transport a. _ transport materials across membrane from low to high concentration; ‘up the concentration gradient’ ____________________________________________________ b. _ requires the use of energy ______________________________________________
- Comes from splitting of _ ATP molecule ____________________________________
- Changes shape of _ transporter molecules _, called a _ pump _
- Transports ions: _ Na + , K + , H + , Ca 2+ , I , and Cl _____________
- _ 40% _ of a cell’s ATP expended on active transport
What drug can be lethal to ATP production? _ cyanide _________
Figure 3.9, page 55: 1 point each = 2 points
Look at Figure 3.9 on page 55 and read over the section on Active Transport on page 55 in your textbook.
1.
Explain how the sodium- potassium pump works. _ sodium-potassium pump expels sodium (3) from cell and brings in potassium (2) and acts as an enzyme to split ATP ____________________
2.
What is the role of ATP in the operation of the sodium-potassium pump? _ ATP adds a phosphate group to the pump protein, which changes the pump’s three-dimensional shape ___
2.
Transport in Vesicles ¼ point each = 2 ¾ points a. _ vesicles _: small sacs formed by budding off of membranes b. Functions:
(1) _ Transport substances within the cell from one structure to another ______________
(2) _ Take in substances from ECF and transport substances out to ECF _______________ c. Two main types of vesicular transport: _ endocytosis _ and _ exocytosis _
ENDOCYTOSIS
_ materials moved into cell; capturing substance or particle from outside the cell by engulfing it within membrane folds from the cell membrane and releasing it into cytosol
Two types of endocytosis:
1. Phagocytosis: _ ”cellular eating” ____________________________________________
(1) Attachment: _ phagosome
Particles bind to plasma membrane receptors
(2) Phagosome formation: _
________________
Projections called pseudopods extend surround particles and portions of the membrane fuse to form a vesicle; extensions of the plasma membrane and cytoplasm; pseudopods vesicle formed called a
________________________________________________________
(3) Phagosome-lysosome fusion: _ Phagosome enters the cell, fuses with lysosomes
(4) Digestion: _ Lysosome enzymes break down phagosome’s contents; any
undigested content remains in the phagosome, now called a residual body ____
What types of cells does this only occur in? _ phagocytes (certain white blood cells and macrophages) _________________
2. Bulk-phase Endocytosis: _ ”cellular drinking” [pinocytosis] ______________________
(1) _ plasma membrane folds inwards _, forms pinocytotic vesicle that pulls in
_ tiny droplets of ECF containing dissolved substances _ to be surrounded
(2) Vesicles _ detaches or “pinches off” _ of plasma membrane enter _ cytosol _
(3) Vesicles fuse with _ lysosome _, and then _ enzymes _degrade engulfed solutes
(4) Degraded solutes, like _ amino acids _ and _ fatty acids _ leave lysosome to be used
elsewhere in the cell
6 ¾ points possible
4

EXOCYTOSIS ¼ point each = 1 point
_ materials removed from cell; process of vesicles fusing with the plasma membrane and secretes their contents to the outside of the cell ________________________________
Do all cells carry out exocytosis? _ yes _______________
Exocytosis is most important in these two types of cells:
(1) _ secretory cells ________________________
Release digestive enzymes, hormones, mucus, and other secretions
(2) _ nervous cells _________________________
Releases neurotransmitters
CHECKPOINT: 2 points
1.
What is the key difference between passive and active transport? _ passive  high to low concentration; needs no energy/ active  low to high concentration; needs energy ___________
IV. Cytoplasm ¼ point each = 2 ¼ points
OBJ: Describe the structure and Functions of cytoplasm, cytosol, and organelles.
1.
Cytoplasm defined: _ everything inside plasma membrane excluding nucleus ________________
A.
Cytosol
1. Cytosol defined: _ everything inside plasma membrane excluding nucleus and membranebound organelles ________________________________________________________________
2. What is cytosol composed of? _ 75%-90% of cytosol is water, the rest is composed of dissolved solutes and suspended particles ____________________________________________
3. What do the chemical reactions that occur in the cytosol help the cell with? _ Maintain cell
structure and enable cell growth ____________________________________________________
CYTOSKELETON a. Extends throughout cytosol b. Network of three different types of protein filaments:
– _ microfilaments _____________________________
– _ intermediate filaments ______________________
– _ microtubules ______________________________ c. Microfilament functions:
– Provide mechanical support and help generate movement
– Anchor cytoskeleton to integral proteins
– Provide support for microvilli
d. Microvilli functions:
– Muscle contractions
– Cell division
– Cell locomotion
e. Intermediate filaments functions:
– Found in parts of cells subjected to tension (stretching)
– Hold organelles in place
– Attach cells to one another
f. Microtubules functions:
– Help determine cell shape
– Function as transport system for organelle movement
– Secretory vesicles
– Migration of chromosomes
– Create movement of cilia and flagella
5 ¼ points possible
5

B.
Organelles ¼ point each = 3 ½ points
Label the lettered organelles on the diagram pictured below : a.
smooth ER b.
GOLGI COMPLEX c.
MITOCHONDRIA d.
ROUGH ER e.
RIBOSOMES f.
CILIA g.
MICROVILLI h.
CENTRIOLES i.
NUCLEOLUS j.
LYSOSOME k.
PLASMA MEMBRANE l.
PEROXISOME m.
NUCLEUS n.
CYTOSOL/CYTOPLASM
Describe briefly the function of each organelle listed below: ¼ point each = 2 ¾ points
1. Centrosome: role in cell division
2. Cilia: motile projections; increase surface area
3. Flagella: motile projections
4. Ribosomes: synthesize proteins
5. Rough Endoplasmic Reticulum: production of proteins for export
6. Smooth Endoplasmic Reticulum: site of lipid synthesis
7. Golgi Complex: sorts, modifies, packages proteins & lipids; forms lysosomes
8. Lysosomes: vesicles with digestive enzymes
9. Peroxisomes: vesicles with enzymes to detoxify drugs, alcohol, harmful substances; hydrogen peroxide
10. Proteasomes: vesicles that dispose of dying cells
11. Mitochondria: site of ATP production
CHECKPOINT: 2 points each = 4 points total
1.
What does cytoplasm have that cytosol does not? _ includes membrane-bound organelles ___
2.
What is an organelle? _ specialized structures inside cells that have specific shapes and functions
V. Nucleus ¼ point each = 1 ¾ points
OBJ: Describe the structure and functions of the nucleus.
Label the lettered organelles on the diagram pictured below :
A.
NUCLEAR ENVELOPE
B.
CHROMATIN
C.
NUCLEOLUS
D.
NUCLEAR PORES
E.
ROUGH ER
F.
POLYRIBOSOMES
Describe briefly the function of nucleus below: controls cellular structure, directs cellular activity, produces ribosomes in nucleoli
CHECKPOINT: 2 points
1.
Why is the nucleus so important in the life of a cell? _ because it contains the genes that control cellular activity and cellular structure and pass on hereditary traits _______________________
12 ¼ points possible
6

VI. Gene Action: Protein Synthesis ¼ point each = 2 points
OBJ: Outline the sequence of events involved in protein synthesis.
1. What do the proteins made during protein synthesis determine for cells and organisms?
Physical and chemical characteristics of cells/organisms
2.
Where in the cell and on what is the code for making proteins stored?
Genes on DNA in cell nucleus
3.
Define protein synthesis.
The making of protein molecules through transcription and translation processes
A. Transcription
1. Where does this process take place in the cell?
Cell nucleus
2. What enzyme catalyzes this process?
RNA polymerase
3. Compare the three types of RNA (you may need to do some research) in the chart below:
0.04 points per box
B. Translation
1. What happens during translation?
Process in which mRNA associates with ribosomes and directs synthesis of protein by
converting the sequence of nucleotides in mRNA into a specific sequence of amino acids
2. Label and color (first fill in the color key on the lower right side) the chart below:
¼ point colored in; ½ point molecule colored in; 1 point each step 1 &2 = 3 points
5 ¼ points possible
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¼ point each = 1 ½ points
VII. Somatic Cell Division ¼ point each = 1 ½ points
OBJ: Discuss the stages, events, and significance of somatic cell division.
1. Why are body cells replaced? _ because they become damaged, diseased, or worn out ________
A. Interphase
1. What is the first step? _ nucleus replicates DNA _____________________________________
2. What else occurs during interphase? _ cell manufactures additional organelles and cytosolic
components in anticipation of cell division _________________________________________
B. Mitotic Phase
1. What becomes visible during this phase? _ chromosomes _____________________________
1. Nuclear Division: Mitosis
a. Four stages:
(1) _ prophase ____________________
- _ chromatin fibers condense and shorten into chromosomes ______________________
- _ chromosomes become chromatids __________________________________________
- _ centromeres hold chromatids together ______________________________________
- _ mitotic spindles form _____________________________________________________
(2) _ metaphase ___________________
- _ centromeres align along metaphase plate ____________________________________
(3) _ anaphase _____________________
- _ centromeres split, separating chromatid pairs _________________________________
- _ chromatids pulled by spindles to opposite poles _______________________________
(4) _ telophase _____________________
- _ chromosomes stop moving _______________________________________________
- _ nuclear envelope starts to reform _________________________________________
- _ chromatin condenses ____________________________________________________
- _ cell pinches inward forming cleavage furrow __________________________________
2. Cytoplasmic Division: Cytokinesis
a. Division of the _ cytoplasm __________________________
b. Begins with formation of a _ cleavage furrow _ in plasma membrane that pinches inward
VIII. Cellular Diversity
OBJ: Describe how cells differ in size and shape.
• Average humans has about 100 trillion cells of varying sizes
– Cell size is measured in micrometers (µm)
• 1 micrometer = 1 one-millionth of a meter
• Largest cell in human body is an oocyte with a diameter of 140 µm
– Average hair strands is ~100 µm in diameter
• Cells can be round, oval, flat, cube-shaped, column-shaped, elongated, star-shaped, cylindrical, or disc-shaped
– Shape is related to function
** An oocyte is a female germ cell or gamete.
5 points possible
8

Figure 3.22, page 69: 1 point ; ¼ point each
1. How is the shape of the cells in Figure 3.22 related to their functions?
Sperm cell: uses flagella for locomotion
Nerve cell: dendrites like telephone wires to transmit messages
Smooth muscle cell: long cylinder to allow it to stretch and contract
Red blood cell: disc-shaped to allow ease of movement through circulatory system without risk of clogging
IX. Aging and Cells
OBJ: Describe the cellular changes that occur with aging
As we age our cells ability to divide is diminished.
DNA sequences that code for cell division break down.
Free radical control becomes limited.
Autoimmune responses slow down.
Critical thinking applications: 2 points each = 4 points
1.
Jethro loves his French fries super-sized with extra salt. He dropped Anatomy & Physiology last semester but remembers something about a pump. “Hey, I’m a big guy. I need the extra salt to power my sodium pump.” How well does Jethro remember his Anatomy & Physiology?
Salt is composed of sodium and chloride; sodium-potassium pump transports sodium out of the cell and potassium into the cell by active transport. ATP powers the pump.
2.
Your friend Sam works a highly stressful job as a neurosurgeon. His diet during long, extended shifts consists mainly of chocolate and Sweet Ice Tea. He has been sick a lot and feels that his job is prematurely aging him. Your response to Sam is that he should examine his diet. Why do you respond this way?
Sam has several risk factors that could be contributing to his “premature aging”. High levels of stress can shorten the protective telomeres on the ends of chromosomes, contributing to aging and eventual death of cells. Glucose cross-links that form between proteins can contribute to loss of elasticity, which ages tissues. His immune system may be malfunctioning, producing autoimmune responses that can also affect the aging process.
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