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Mrs. Jackson’s Absolute Bare
Minimum Module 1 Review
•
An organism is any individual living thing.
• Living things share some common characteristics:
– All are made of one or more cells.
– All need energy for metabolism.
• Metabolism: All of the chemical processes in
an organism that build up or break down materials.
– All respond to their environment.
– Stimuli, or physical factors, include light, temperature,
and touch.
– All have genetic material (DNA) that they pass on to
offspring (universal code)
Life depends on hydrogen bonds in
water.
• Water is a polar molecule.
– Polar molecules have slightly charged regions.
1. Hydrogen bonds
form between slightly
positive hydrogen
atoms and slightly
negative atoms.
(oxygen)
Atom: Oxygen
Charge: Slightly
negative
_
O
H
+
H
+
Atom: Hydrogen
Charge: Slightly positive
– Nonpolar molecules do not have charged regions.
• Hydrogen bonds are responsible for important
properties of water.
– High Specific Heat: water resists changes in temp.
– Provides stability of temperature for land
masses surrounded by water & for the
temperature of the human body, & makes it an
effective cooling agent.
– Cohesion: water molecules stick to each other.
– Adhesion: water molecules stick to other things.
– Ice floats on water: one of the only solids to float
on its liquid form – due to arrangement of water
molecules due to charged regions. Provides
insulation for water below (stays at about 4
degrees C – freezing point is 0 C)
Many compounds dissolve in water.
• A solution is formed when one substance dissolves in
another. A solution is a homogeneous mixture.
– Solvents dissolve other substances.
– Solutes dissolve in a solvent.
solution
• “Like dissolves like.”
–Polar solvents dissolve polar solutes.
–Nonpolar solvents dissolve nonpolar
solutes.
–Polar substances and nonpolar
substances generally remain
separate.
–Example: Oil (non-polar) and
water (polar)
pH
<7=Acid (more H+)
7=Neutral
>7=Base (less H+)
Maintaining homeostasis
*Buffer: Helps to maintain pH.
Speaking of homeostasis…
• Homeostasis refers to your body maintaining
stable, constant internal conditions.
• This may include:
– Regulation of temperature (thermoregulation) Ex.:
sweating during exercise
– Regulation of pH (i.e. buffers)
– Regulation of oxygen delivery (for cellular
respiration!). Ex: heart beating faster during exercise
– Regulation of water (osmoregulation - regulation of
water concentrations in the bloodstream, effectively
controlling the amount of water available for cells to
absorb.)
Control systems work together
through feedback
• Feedback: Information from sensor that allows a control center to
compare current conditions to a set of ideal values.
– Feedback loop: Sensorcontrol centertargetsensor….
• Negative feedback loops: control system counteracts any change in
the body that moves conditions above or below a set point
(reversing change to return conditions to their set points)-most
functions in the body are regulated this way.
– Ex.: Thermostats, holding your breath
• Positive feedback loops: Control center uses information to increase
rate of change away from set points.
– Ex.: Cut finger increases clotting factors in blood.
Carbon atoms have unique bonding
properties.
1. Carbon forms covalent bonds (strong
bonds) with up to four other atoms,
including other carbon atoms (has 4
unpaired electrons in its outer energy level)
2. They can form large, complex molecules
Carbon atoms have unique bonding
properties – Slide 2
3. Carbon can form single, double, or triple bonds
4. Carbon forms isomers
– Isomers are compounds that have the same chemical
formula, but different structural formulas
• Example: C4H10
• Only carbon has these 4 characteristics
Many carbon-based molecules are made of many small
subunits bonded together.
• Monomers are the individual subunits.
• Polymers are made of many monomers.
Carbohydrates
Polymer
polysaccharide (or disaccharide if there are only 2 monomers)
Structure:
Monomer: Monosaccharide (glucose, fructose)
Made of atoms C, H, O
Function
-
- Provide a quick source of energy
- -Makes up cell wall in plants (cellulose)
-Energy storage (starch in plants, glycogen in animals)
Lipids
LIPIDS
Monomer
(structure)
glycerol & fatty acids; polar heads & fatty acid tails
made of atoms C, H, O, sometimes P, sometimes N
Polymer
triglycerides; phospholipids
Examples
Function
Fats, oils, cholesterol, steroids, waxes, phospholipids
-
Broken down to provide energy (takes longer than carbs)
Used to make steroid hormones (control stress, estrogen,
testosterone)
- Phospholipids make up all cell membranes
- (tend to be non-polar)
Proteins
Molecule 
Monomer
(structure)
Polymer
Function
More function
Proteins
Monomer: Amino acid connected by peptide bonds
Atoms: C,H,O, N, sometimes S
Polypeptide (protein)
Enzymes (catalyze biochemical reactions), hemoglobin
(transports oxygen in blood), muscle movement, collagen
- Have a side group (R) that makes each amino acid (and
therefore protein) different
- -3D structure makes them active – change of structure
(denature) = change of function
Nucleic acids
Molecule 
Monomer
(Structure)
Polymer
Nucleic acids
Nucleotide (5-carbon sugar, phosphate group, & base)
made of atoms C, H, O, N, P
Nucleic acid
Examples
DNA & RNA
Function
- Order of the bases makes every living thing unique
- DNA stores genetic information
- RNA builds proteins
• How are polymers made from monomers?
• This is dehydration synthesis. During this type of
reaction, a water molecule is removed (an –OH from
one simple monomer and an –H from another to form a
water molecule. This joins two monomers together to
form a polymer. When adding another monomer to the
dimer, another water molecule needs to be removed.
Monomer called Glucose
monomer-OH + monomer-H polymer + H2O
Dimer called Maltose
Hydrolysis
• A polymer needs to break apart (the
carbs, proteins, and lipids we ingest are
too big for us to use)
– Water breaks apart into (-OH) and (-H) and
splits the polymer into monomers
– The (-OH) and (-H) bond to each monomer to
make them stable molecules
• polymer + H2O  monomer-OH +
monomer-H
Chemical reactions release or
absorb energy.
• Activation energy is the amount of energy that needs to
be absorbed to start a chemical reaction
Catalysts are substances that speed up chemical reactions
Decrease activation energy
Increase reaction rate
Enzymes allow chemical reactions to occur
under tightly controlled conditions.
• Enzymes are catalysts in living
things.
–Enzymes are needed for
almost all processes.
–Most enzymes are proteins.
Disruptions in homeostasis can
prevent enzymes from functioning.
• Enzymes function best in a small
range of conditions.
–Changes in temperature or pH can
break hydrogen bonds –
DENATURES enzyme (changes 3D
structure)
•An enzyme’s function depends on
its structure.
An enzyme’s structure allows only certain
reactants to bind to the enzyme.
• Substrates: reactants that bind to an enzyme
• Active site: area on the enzyme where substrates bind
What else can affect enzyme activity?
• Enzyme Concentration
If we keep the concentration of the substrate constant and increase the
concentration of the enzyme, the rate of reaction increases linearly.
(That is if the concentration of enzyme is doubled, the rate doubles.)
This is because in practically all enzyme reactions the molar concentration
of the enzyme is almost always lower than that of the substrate.
• Substrate Concentration
If we keep the concentration of the enzyme constant and increase the
concentration of the substrate, initially, the rate increases with substrate
concentration, but at a certain concentration, the rate levels out and
remains constant
So at some point, increasing the substrate concentration does not
increase the rate of reaction, because the excess substrate cannot find
any active sites to attach to.
Exothermic reactions release more
energy than they absorb.
• Excess energy is released by the reaction.
– Energy “exits” the reaction. (Exo = exit)
Endothermic reactions absorb more
energy than they release.
• Energy is absorbed by the reaction to make up the
difference.
– Energy goes into the reaction. (Endo = “into”)
• The Cell Theory:
–All organisms are made of
cells.
–All cells come from other
cells.
–The cell is the basic unit of
structure & function in living
things.
All cells share certain characteristics.
• Cells tend to be microscopic.
• All cells are enclosed by a
membrane.
• All cells are filled with cytoplasm.
• All cells have ribosomes.
• All cells have genetic
material (DNA)
There are two cell types:
• Eukaryotic cells
– Have a nucleus
– Have membranebound
organelles
• Prokaryotic cells
– Do not have a
nucleus (still have
DNA)
– Do not have
membrane-bound
organelles
Review
Eukaryotes
• Have nucleus (DNA)
• Have membrane-bound
organelles
• Larger size because of
organelles (Organelles divide
up the functions of the cell
and allow eukaryotic cells to
have more volume.)
• More complex
• Unicellular or multicellular
Prokaryotes
• No nucleus (still have DNA)
• No membrane-bound
organelles
• Smaller size because of lack of
organelles
• Less complex
• Unicellular
Organelles and Functions
See 3.1/3.2 PowerPoint!
How do membrane-bound organelles facilitate the transport of
materials within the cell?
The rough ER works with the Golgi…
• Vesicle: Small membrane-bound sacs that divide some materials
from the rest of the cytoplasm and transport these materials
within the cell.
• Proteins (such as secretory & membrane proteins) made by
ribosomes on the rough ER are packaged in vesicles and sent to
the cell membrane or Golgi Apparatus.
• The Golgi Body processes & sorts the proteins, then packages
them into vesicles for storage, transport, or secretion from the
cell membrane in new vesicles.
Levels of Organization
• OrganellesCellsTissuesOrgans 
Organ SystemsOrganisms
There are advantages to being multicellular rather
than unicellular. These include allowing:
• Allows the organism to be larger & have more
efficient movement
• Cell differentiation (having different types of cells
with different functions) – specialization of cells,
tissues, organs, organ systems allows for efficient
performance of a variety of functions.
• The organisms to be more complex
Cell membranes are composed of two
phospholipid layers.
• The cell membrane has two major functions
1. Forms a boundary between inside and
outside of the cell
2. Controls passage of materials in & out of cell
Phospholipid Bilayer
• Forms a double layer surrounding
a
cell
• Head is polar (attracted
to
water) and forms hydrogen bonds with
water
• Tails are nonpolar
(repelled by water)
Passive transport does not require
energy (ATP) input from a cell.
• Molecules can move across the cell
membrane through passive transport.
• Three types of passive transport:
– Diffusion: movement of molecules from high to
low concentration
– Osmosis: diffusion of water
– Facilitated diffusion (see slide)
Diffusion and osmosis are types of
passive transport (NO ENERGY)
• Molecules diffuse down a concentration
gradient.
– High to low concentration
How do different solutions affect cells?
• There are 3 types of
solutions:
1. Isotonic: solution has
the same
concentration of
solutes as the cell.
•
•
Water moves in and out
evenly
Cell size stays constant
How do different solutions affect cells?
• There are 3 types of
solutions:
2. Hypertonic: solution
has more solutes than
a cell
•
•
More water exits the cell
than enters
Cell shrivels or dies
How do different solutions affect cells?
• There are 3 types of
solutions:
3. Hypotonic: solution
has fewer solutes than
a cell
•
•
More water enters the
cell than exits
Cell expands or bursts
Some molecules can only diffuse through
transport proteins – this is FACILITATED
DIFFUSION
• Some molecules cannot easily diffuse across
the membrane
– Ex: glucose (needed by cell to make energy)
• Facilitated diffusion is diffusion through
transport proteins
• DOES NOT USE ENERGY
Video 
Active Transport
• Cells use energy (ATP) to transport materials that
cannot diffuse across a membrane.
• Drives molecules across a membrane from
lower to higher concentration
– Goes against the concentration gradient
TYPES OF ACTIVE TRANSPORT
• Endocytosis: Brings materials into
cell (Endo=into)
• Exocytosis: Releases materials
out of cell (Exo=Exit)
• Pumps (see next slide)
Sodium-Potassium Pump (A type of
pump)
• Uses a membrane protein to pump three Na+
(sodium ions) across the membrane in
exchange for two K+ (potassium ions)
– ATP (energy) is needed to make the protein
change its shape so that Na+ and K+ can move
through it and cross the membrane
• Helps the heart contract, helps regulate blood
pressure, allows neurons to respond to stimuli
and send signals
Scientific Terms
• Hypothesis: A proposed, testable answer to a
scientific question.
• Observation: the use of our senses,
computers, and other tools to gather
information about the world.
– Ex.: Studying the interactions between gorillas by
observing their behavior.
Other important science terms
• Inference: A conclusion reached on the basis of evidence and
reasoning.
• Law: A law that generalizes a body of observations. At the
time it is made, no exceptions have been found to a law. It
explains things but does not describe them; serves as the
basis of scientific principles.
• Theory: A proposed explanation for observations and
experimental results that is supported by a wide range of
evidence – may eventually be accepted by the scientific
community.
• Principle: A concept based on scientific laws and axioms (rules
assumed to be present, true, and valid) where general
agreement is present.
• Fact: An observation that has been repeatedly confirmed.
Controlled experiments
• Only one independent variable should be
changed in an experiment.
• Other conditions must stay the same and are
called constants.
• Controlled experiments must have a control
group – everything is the same as the
experimental groups but the independent
variable is not manipulated.
– Example: When testing blood pressure medication,
control group receives none of the active ingredient.
• A large number of test subjects or trials is ideal.
4.1 How do living things get ATP?
• ATP is the energy carrier in living things – it is usable
energy for the cell.
• ATP stands for Adenosine triphosphate.
• Living things get ATP from breaking down carbon
based molecules. (carbohydrates, lipids, proteins)
• Needed for cellular activities (i.e. active transport)
Starch molecule
Glucose molecule
This is how it works
phosphate removed
Photosynthesis
• The process of photosynthesis captures energy
from sunlight and converts it into sugar (glucose).
• This process happens in organisms called
autotrophs or producers. (Need to make their own
food)
• This process takes place in an organelle called the
chloroplast (this is a plastid).
• The chloroplast has a green pigment in it called
chlorophyll that is responsible for capturing the
light energy.
So how does photosynthesis work?
The first stage of photosynthesis is called the
Light Dependent Stage.
• Light is captured by the chlorophyll in the
thylakoid of the chloroplast.
So how does photosynthesis work?
The second stage of photosynthesis is called the
Light Independent Stage/ Calvin Cycle/ Dark
Cycle.
• This process takes place in the stroma of the
chloroplast.
The chemical formula for
photosynthesis
• 6CO2 + 6H2O + light
Carbon dioxide plus water plus light
(reactants)
(products)
C6H12O6 + 6O2
yields
Glucose and oxygen
Purpose of Cellular Respiration
• To make ATP from the energy stored in glucose
– Glucose comes from an organism doing
photosynthesis themselves or from eating foods
containing glucose
–Remember: the purpose of photosynthesis
was just to get glucose
–Takes place mostly in mitochondria
Glycolysis
• Takes place in cytoplasm (eukaryotes and prokaryotes do
this step since all cells have cytoplasm)
• This portion of CR does NOT require oxygen (anaerobic)
Kreb’s Cycle (Citric Acid Cycle)
• Takes place in matrix of mitochondria (only
in eukaryotes)
Electron Transport Chain (ETC)
• Takes place in inner membrane of mitochondria (cristae)
– Folded to create more surface area for reactions to
produce more ATP in a small space
Equation for Cellular Respiration
C6H12O6 + 6O2
6CO2 + 6H2O + 36ATP
 Like the reverse of photosynthesis
Energy transfers:
Photo: LightCPE
CR: CPECPE
What happens when there’s no/not
enough oxygen or there are no
mitochondria?
• Answer: Fermentation
–Two Kinds:
• Lactic Acid Fermentation
• Alcoholic Fermentation
• Allows glycolysis to
continue making ATP
without oxygen