BASIC
BUILDING
BLOCKS OF
LIFE
Building from the atom
to the organism
From smallest to biggest
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Atoms
Molecules
Cells
Tissues
Organs
Organisms
What are the basic building block of
all things?
• Everything in the universe is made of
matter
– Anything that occupies space and has mass
• REMIND ME: What is mass ?
Atoms build all things
• Atom – simplest particle of an
element that has all the properties of
the element.
• Element – found on the periodic
table. They cannot be broken down
chemically into simpler forms of
matter.
– Atoms of the same type combine
together to form elements
Important information about the
atom
• Atom is made of 3 basic particles:
– Protons:
• Positive charged particle in the nucleus
• The number of protons determines the element.
This number is known as the atomic number on the
periodic table.
– Neutrons:
• Neutral charged particle in the nucleus
• An element may have different numbers of neutrons,
this is called an isotope.
Electrons
• Electrons
– Negatively charged particle orbiting the
nucleus
– The area the electrons orbit is called the
orbital
– Electrons are responsible for combining
atoms
Combining Atoms
• Things aren’t made of individual elements.
They must combine to form more complex
structures.
• Molecule – combination of 2 or more atoms
• Compound – combination of 2 or more
molecules
– Atoms make up elements
– Atoms make up molecules
– Molecules make up compounds
How do atoms and molecules
combine?
• Elements and molecules are held together
by chemical bonds
– Ionic bonds – when atoms are held together by
the attraction of opposite charges, electrons are
gained or lost (NaCl)
– Covalent bonds - when atoms are held together
by one or more pairs of electrons shared
between atoms (H2O)
Atoms want to be stable
• To be stable, all elements want their orbitals
full
• To be full, an element must look like a
noble gas (last column on the periodic table)
– Thus, elements must do 1 of two things:
• Take or lose electrons
• Share electrons with another atom
• LET’S LOOK AT SOME EXAMPLES
Let’s examine the periodic table
Try These
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Carbon (C)
Hydrogen (H)
Oxygen (O)
Nitrogen (N)
Phosphorus (P)
Sulfur (S)
Let’s put some atoms together
• Each atom can combine with a maximum of
4 other atoms
• This number depends on the number of
electrons it gains/loses or has to share
EXAMPLE
• CH4 (the subscript tells you how many
atoms of each type you have)
– How many electrons does carbon have to gain
or lose? (1 carbon)
– How many electrons does hydrogen have to
gain or lose? (4 hydrogens)
• This is how many places the atom can
combine with another atom(s)
EXAMPLE (cont)
• Carbon has 4 spaces
• 4 Hydrogens have 1 space each
• The atom with the most number of spaces is
going to go in the middle
How do we put them together?
-CH- H- H- H-
Try these with the model kits
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CH4
H2O
NH3
CCl4
Special bond between molecules:
HYDROGEN BONDS
• Electrons are usually not shared equally
between atoms in a covalent bond
• Some atoms want electrons more than
others
– EXAMPLE: In water, oxygen wants the
electrons more than hydrogen
• QUESTION: What becomes the charge on
the hydrogen and the oxygen?
Polarity
• ANSWER:
– Oxygen only has a partial negative charge
– Each hydrogen has a partial positive charge
• When a molecule has an uneven sharing of
electrons, this is called a polar compound
Water – The molecule of life
• As a result of this polarity in molecules,
many molecules in living things create
hydrogen bonds.
Properties from Hydrogen bonds
• Because hydrogen bonds help to bond
different molecules together, water gets
some interesting properties:
• Cohesion – an attractive force that holds
molecules together in a single substance
– Helps the upward movement of water in a
plants roots to its leaves
– Surface tension
Properties from Hydrogen bonds
• Adhesion – attractive force between two
different substances
– Capillarity – attraction between molecules that
results in the rise of the surface of a liquid
when in contact with a solid
• EXAMPLE: allows water to rise up side of roots in
plants
Solutions and solubility
• Most things in life occur in water or are
made of water.
• Solution – mixture in which one or more
substances is dissolved evenly in another
substance
– Solute – substance dissolved in a
solvent
– Solvent - the substance in which a
solute is dissolven
Solutions in water
• In water, all
solutions are
known as
AQUEOUS
SOLUTIONS
Acids and bases (always in
aqueous solutions)
• Water is able to split apart into two ions
H2O  H+ + OH• Acid solutions have a greater number of
hydrogen ions (H+)
• Base solutions have a greater number of
hydroxide ions (OH-)
– Also referred to as alkaline
Acids and bases
• Living things need to live in a specific
range of acid or base to be healthy
– This is why acid rain kills so many
fish in lakes and streams
• pH scale measures relative
concentrations of H+ ions and OH- ions
Biological Molecules
• Organic Compounds
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CARBOHYDRATES
PROTEINS
LIPIDS
NUCLEIC ACIDS
Carbon bonding
• Organic compounds – compounds
made primarily of carbon
• Most living organisms are made up
of organic compounds
• Why do you think that so many
molecules use carbon?
Functional groups – TURN TO
PAGE 52
• ANSWER: Carbon has 4 bonding sites
giving it a lot of versatility.
• Functional groups influence the
characteristic of molecules as they go
through chemical reactions:
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Hydroxyl
Carboxyl
Amino
Phosphate
Carbohydrates
• Carbohydrates are organic molecules that
are composed of carbon, hydrogen and
oxygen
– Monosaccharide – a simple sugar. These are
the building blocks for more complex
carbohydrates (glucose, fructose, galactose)
– Disaccharide – sugar made of 2
monosaccharides (sucrose)
– Polysaccharide – a complex sugar made up of
three or more monosaccharides (starch)
Carbohydrates – TURN TO
PAGE 53 AND 55
• Notice the pictures of some example
carbohydrates on pg. 55 (Figure 3-6)
– These are the monosaccharides
• Disaccharides are formed as seen on pg. 53
(Figure 3-4)
– Condensation reaction : combines two
monosaccharides to form a disaccharide and
produces water
– Hydrolysis : the opposite of a condensation
reaction
Carbohydrates
• Carbohydrates serve a couple of purposes:
– Source of energy
• Glucose is the main source of energy
for cells
– Structural material in the cell
• Cellulose is a polysaccharide that give
strength and rigidity to plant cells
(makes up about 50 percent of wood)
Proteins
• Proteins are organic molecules composed
mostly of carbon, hydrogen, oxygen and
nitrogen
• A series of protein monomers are linked
together to form an amino acid
– There are a total of 20 amino acids
– Amino acids are held together by peptide bonds
• Long chains of amino acids are often called
a polypeptide
Proteins – TURN TO PAGE 56
AND 57
• Amino acids are made of a central carbon with different
groups covalently bonded around it (p. 56 Figure 3-7)
– Carboxyl group
– Amino group
– Hydrogen
– R group (different for every amino acid)
• Peptide bonds are formed and broken apart like
carbohydrates (p. 57 Figure 3-8)
• Polypeptide: very long chains of amino acids
ENZYMES
• Enzymes : special type of protein that is
used to facilitate many biological reactions
(also known as a biological catalyst)
• Enzymes act like a lock and key (only one
type of substrate can fit in the enzyme’s
active site)
– Substrate: substance being catalyzed
– Active site: where the substrate fits into the
enzyme
Lipids – TURN TO PAGE 59
• Lipid: Organic molecule made mostly of carbon
and hydrogen
• IMPORTANT NOTE: Lipids are nonpolar (do
not dissolve in water)
– Fatty acid: made of a long carbon chain with a
carboxyl group at one end
• The long carbon chain is hydrophobic
(another word for does not dissolve in water)
• The carboxyl group is hydrophilic (dissolves
in water)
Lipids
• Lipids important to living things
– Triglycerides: composed of 3 fatty acid chains held together
by a glycerol
• Store energy in the body
– Phospholipids: composed of 2 fatty acid chains held
together by a glycerol
• Compose the cell membrane
– Wax: composed of 1 fatty acid chain joined to an alcohol
chain
• Waterproof and act as a protective coat
– Steroids: does not have any fatty acid chains
• Many animal hormones are steroids
Nucleic Acids – TURN TO
PAGE 60
• Very complex molecule with the following
parts
– Sugar backbone (deoxyribose)
– Phosphate group
– Nitrogenous base (used to link nucleic acid
strands together)
• Nucleotide: the monomer that makes up a
nucleic acid strand
Nucleic Acids
• 2 main types of nucleic acids:
– Deoxyribonucleic acid (DNA) – contains a
template that possesses all the information
needed to produce and sustain a cell
– Ribonucleic acid (RNA) – transfers information
from the DNA to ribosomes to produce protein
A View of the Cell
Plant cell
The History of the Cell
• The Cell
–The basic unit of an organism
–Discovery made possible by
the invention of the
microscope
Microscopes and Cells
• 1600’s.
–Anton van
Leeuwenhoek
first described
living cells as
seen through a
simple
microscope.
Microscopes and Cells
–Robert Hooke used the first
compound microscope to
view thinly sliced cork cells.
•Compound scopes
use a series of lenses
to magnify in steps.
•Hooke was the first
to use the term
“cell”.
Microscopes and Cells
• 1830’s.
–Mathias Schleiden identified
the first plant cells and
concluded that all plants
made of cells.
- Thomas Schwann
made the same
conclusion about
animal cells.
Cell Theory:
• All organisms are made up of
one or more cells.
• The cell is the basic unit of
organization of all organisms.
• All cells come from other cells
all ready in existence.
Two Basic Cell Types
1) Prokaryote
–Lacks internal
compartments.
–No true nucleus.
–Most are single-celled
(unicellular) organisms.
–May or may not have a
cell wall
–Examples: bacteria
Two Basic Cell Types
2) Eukaryote
–Has several internal
structures (organelles).
–True nucleus.
–Either unicellular or
multicellular.
unicellular example: yeast
multicellular examples:
plants and animals
6 Kingdoms of Life
• Kingdom: the highest category for
describing similarities between organisms
• Prokaryotic
– Eubacteria: traditional bacteria
– Archaebacteria: “extreme” bacteria
• Eukaryotic
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Protists
Fungi
Plant
Animal
Organization – from
broadest to most specific
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Kingdom
Phylum
Class
Order
Family
Genus
Species
The Parts of The Eukaryotic Cell
1) Boundaries
A) Plasma Membrane
- Serves as a boundary
between the cell and its
external environment.
- Allows materials to pass
in and out of the cell.
- “Fluid mosaic” model
1) Boundaries
B) Cell’s surface area vs.
it’s volume
-- Because the ratio between
volume and surface area do not
increase at a constant rate, the
size of the cell is limited
-- There is not enough surface
area to import nutrients and
export wastes
1) Boundaries
C) Cell Wall
- Surrounds the plasma
membrane of the cells of
plants, bacteria, and fungi.
- Plant cell walls contain
cellulose while fungi cell
walls contain chitin.
The Parts of The Eukaryotic Cell:
2) Controls
A) Nucleus
•Regulates cell function.
•Surrounded by a doublelayered membrane (nuclear
enveloped) with large pores
that allow materials to pass
in and out of the nucleus.
•Contains chromatin – long
tangles of DNA.
2) Controls
B) Nucleolus
•Found in the nucleus
and responsible for
ribosome production.
Ribosomes are the sites
of protein production.
The Parts of The Eukaryotic Cell:
3) Assembly
–Cytoplasm
•The jelly-like material that
surrounds the organelles.
–Cytosol
•Part of the cytoplasm that
contains small particles,
but not membrane bound
organelles
The Parts of The Eukaryotic Cell:
4) Transport
A) Endoplasmic reticulum
•Folded membrane that acts
as the cell’s delivery system.
•Smooth E.R. contains
enzymes for lipid synthesis.
•Rough E.R. is studded with
ribosomes for protein
synthesis.
4) Transport
B) Golgi apparatus (or
Golgi body)
•A series of flattened sacs
where newly made lipids
and proteins from the E.R.
are repackaged and
shipped to the plasma
membrane.
The Parts of The Eukaryotic Cell:
5) Storage
A) Vacuoles
•A sac of fluid
surrounded by a
membrane used to store
food, fluid, or waste
products.
5) Storage
B) Lysosomes
•Contain a digestive
enzyme.
•Can fuse with vacuoles to
digest food, or can digest
worn cell parts.
•Also known as “suicide
sacs” because they can also
destroy the whole cell.
The Parts of The Eukaryotic Cell:
6) Energy Transformers
Mitochondria
•Produce the energy for
the cell.
•Also known as the
“powerhouse of the cell”.
•Has a highly folded inner
membrane (cristae).
•Has its own DNA
6) Energy Transformers
B) Chloroplasts
- Found in plant cells and
some protists.
-Transforms light energy
into chemical energy which
is stored in food molecules.
-Contain chlorophyll – a
green pigment that traps
light energy and gives
plants their green color.
The Parts of The Eukaryotic Cell:
7) Support
–Cytoskeleton
•A network of thin, fibrous
materials that act as a scaffold
and support the organelles.
•Microtubules – hollow filaments
of protein (structural support).
•Microfilaments – solid filaments
of protein (aids movement).
The Parts of The Eukaryotic Cell:
8) Locomotion
1) Cilia
•Short, numerous, hair-like
projections from the
plasma membrane.
•Move with a coordinated
beating action.
8) Locomotion
B) Flagella
•Longer, less numerous
projections from the
plasma membrane.
•Move with a whiplike
action.
The Parts of The Eukaryotic Cell:
9) Cell Division
Centrioles
– made of protein.
– play a role in the splitting of
the cell into two cells.
– found in animal and fungi cells.
Comparison between plants and
animals
• Plants have every organelle that animals do,
in addition to the following:
– Cell wall: made from the carbohydrate,
cellulose, this gives the plant cell a much more
rigid structure than animal cells
– Central vacuole: store water for the cell
– Plastids (chloroplasts): usually involved in
photosynthesis or the storage of starches and
other carbohydrates
Composite Animal Cell