Pre-AP Biology Energy Unit
Study Guide Part I
• The Law of conservation of matter/mass :
matter can not be created or destroyed
• However, matter may be rearranged in space
• In chemical reactions, the mass (and # of atoms)
of the reactants must equal the mass (and #of
atoms) of the products
1. What is
activation
energy?
2. Why can heat
supply activation
energy?
1. What is activation energy?
Energy that must be
added for bonds to
become unstable
2. Why can heat supply
activation energy? Heat
increases molecular
motion (and collisions),
which causes bonds to
become unstable
During a chemical reaction:
1. _______ energy is added
2. Bonds become ________
3. Bonds __________
4. Atoms _____________
5. New bonds ________
6. Matter is ____________
During a chemical reaction:
1. Activation energy is added
2. Bonds become unstable
3. Bonds break
4. Atoms rearrange
5. New bonds form
6. Matter is conserved
C2H4
+
3O2
→
2CO2
+
2H2O
1. Count the number of carbon atoms
4. How do the
a. Of the reactants
number and
b. Of the products
types of atoms
2. Count the number of hydrogen atoms
compare
a. Of the reactants
between the
b. Of the products
reactants and
3. Count the number of oxygen atoms
products?
a. Of the reactants
5. Why?
b. Of the products
C2H4
+
3O2
→
2CO2
+
2H2O
1. Count the number of carbon atoms
4. How do the number and
a. Of the reactants 2
types of atoms compare
b. Of the products 2
between the reactants
2. Count the number of hydrogen atoms
and products? equal
a. Of the reactants 4
5. Why? Conservation of
b. Of the products 4
matter/mass
3. Count the number of oxygen atoms
a. Of the reactants 6
b. Of the products 6
1.
2.
3.
4.
5.
What does thermodynamics mean?
What does free energy mean?
State the 1st Law of Thermodynamics:
State the 2nd Law of Thermodynamics:
Discuss how the diagram above shows how
the 1st & 2nd Laws combine:
1. What does thermodynamics mean? Energy transformations
2. What does free energy mean? Capacity to do work
3. State the 1st Law of Thermodynamics: Energy can not be created
or destroyed (but it may be transferred or transformed)
4. State the 2nd Law of Thermodynamics: Every energy transfer or
transformation increases the entropy (disorder) of the system
5. Discuss how the diagram above shows how the 1st & 2nd Laws
combine: organized chemical energy → high entropy heat
Metabolic Equilibrium
1
Metabolic Disequilibrium
2
1. Which of the systems above is a closed, which is an
open system?
2. What eventually happens in a closed system and
what is the result?
3. Give an example of matter that you are exchanging
with the environment.
4. Give an example of an energy transformation
occurring within your body.
5. What would happen if you became a closed system?
Metabolic Equilibrium
1
Metabolic Disequilibrium
2
1. Which of the systems above is a closed, which is an open system? 1
2. What eventually happens in a closed system and what is the result?
Equilibrium, death for organisms
3. Give an example of matter that you are exchanging with the
environment. Oxygen in, carbon dioxide out
4. Give an example of an energy transformation occurring within your
body. Chemical potential energy of food to heat (and recharged ATP)
5. What would happen if you became a closed system? death
Living organisms must exchange energy and
matter with their environment in order to survive.
1.
2.
3.
4.
5.
6.
Draw a picture of a stick-figure person showing:
One form of energy entering
One form of energy exiting
Two forms of matter entering (tied to cellular respiration)
Two forms of matter exiting (tied to cellular respiration)
Write a statement for how #1 & #2 connects to the First
Law of Thermodynamics
Write a statement for how #3 & #4 connect to the Law of
Conservation of Matter/Mass
Living Organisms are Open Systems
Living organisms must exchange energy and matter
with their environment in order to survive.
Chemical
potential energy
Heat (kinetic
energy)
Energy can be
transferred and
transformed but not
created or destroyed
C6H12O6 + 6O2
6CO2 + 6H2O
Matter may be
reorganized but not
created or destroyed; it
is conserved
A molecule is built/broken down
Releases/absorbs energy exergonic/endergonic
Catabolic/anabolic reaction
Ex.: Cellular respiration/photosynthesis
A molecule is built/broken down
Releases/absorbs energy exergonic/endergonic
Catabolic/anabolic reaction
Ex.: Cellular respiration/photosynthesis
A molecule is broken down A molecule is built
Releases free energy Absorbs free energy Exergonic
Endergonic
Catabolic reaction
Ex.: Cellular respiration
Anabolic reaction
Ex.: Photosynthesis
Describe two examples in the diagram
of how to build something up you have
to first break something down.
ATP must be broken down
in order to build protein
Glucose must be broken
down in order to build
ATP
Describe two examples in the diagram
of how to build something up you have
to first break something down.
The glucose molecule represents
chemical potential energy, which
bonds in the molecule represent
high-energy bonds?
The glucose molecule represents
chemical potential energy, which
bonds in the molecule represent
high-energy bonds?
The Carbon-Hydrogen bonds
Adenosine Triphosphate (ATP)
Which part of the
molecule represents
chemical potential
energy? Explain:
Adenosine Triphosphate (ATP)
Phosphate tail = potential
energy in the repulsion of
all the negative charges.
It is a chemical equivalent
of a loaded spring.
What is the mitochondrion’s
function? And how does its
structure (architecture) relate to
its function (job)?
The function of the mitochondrion
is to synthesize/recycle ATP:
ADP + pi → ATP
The double membrane allows for a
H+ gradient, when H+ is allowed to
diffuse down its [ ] gradient ATP
synthase recycles ATP
What structures do
plants have that allow
them to exchange
energy and matter with
their environment?
1. List 4 such
structures:
2. And describe the
function of each:
What structures do
plants have that allow
them to exchange
energy and matter with
their environment?
Chloroplasts – absorb
light for photosynthesis
Roots – absorb water
and minerals
Xylem – transport
water from roots to
leaves
Stomata – exchange
gases and transpiration
of water
1. Energy enters
Earth’s ecosystems
as ____.
2. Photosynthesis
converts CO2 and
H2O into _____, a
form of _______
energy
3. Respiration breaks
down _____ to
recharge ATP and
releases energy as
_____.
1. Energy enters Earth’s
ecosystems as light.
2. Photosynthesis converts
CO2 and H2O into organic
molecules, a form of
chemical potential energy
3. Respiration breaks down
organic molecules to
recharge ATP and
releases energy as heat.
1. Energy enters Earth’s ecosystems as _____ and exits as
____.
2. Describe 2 energy transformations shown in the
diagram above:
3. Describe and explain the path of matter shown:
1. Energy enters ecosystems as light and exits as heat.
2. Describe 2 energy transformations shown in the diagram
above: Light → chemical potential (glucose)→ ATP & heat
3. Describe and explain the path of matter shown: matter
cycles due to the Law of conservation of matter/mass
Draw and label a diagram that shows the flow of
carbon through an ecosystem as a result of the
processes of photosynthesis and cellular respiration
and name the organelles in cells that perform each
of these reactions.
Cellular Respiration (mitochondria)
Organic
Molecules
Carbon
Dioxide
Photosynthesis (chloroplasts)
enzymes
enzymes
1. List three similarities between the two reactions:
2. Describe two differences:
enzymes
enzymes
1. List three similarities between the two reactions:
both use glucose, oxygen, and carbon dioxide,
enzymes are used, energy is transformed
2. Describe two differences:
The reactants and products are switched,
photosynthesis is endergonic while respiration
is exergonic
Discuss the role of process I and II in the
cycling of carbon:
Process I: Photosynthesis removes CO2 from the
atmosphere and uses light energy to convert it
into organic molecules (chemical potential
energy of glucose).
Process II: Cellular respiration breaks down
organic molecules, releasing energy to recycle
ATP and releasing CO2 back into the atmosphere
1. Where does the mass come from for:
acorn → mature oak tree?
2. Where does the mass go when a person
loses weight?
1. Where does the mass come from for: acorn
→ mature oak tree? Most of the mass
comes from CO2, a smaller amount comes
from the H that were removed from H2O
2. Where does the mass go when a person
loses weight? Most of the mas is exhaled as
CO2 gas and some is excreted as H2O
If plants are placed in an environment
without sun and animals are not
provided with food for 48 hours, predict
what will occur to the organisms’ mass
and justify your answer:
If plants are placed in an environment
without sun and animals are not provided
with food, predict what will occur to the
organisms’ mass and justify your answer:
Without sunlight to drive photosynthesis,
plants will not gain mass but they still need
to perform cellular respiration to recycle ATP,
they will use stored glucose (starch) to do so
and thus lose mass by releasing CO2 and H2O.
Similarly, animals will breakdown stored fuel
and lose mass by exhaling CO2 & excreting
H2O.
1. Identify two processes that break-down organic
molecules and return CO2 to the atmosphere:
2. Identify one process that removes CO2 from the
atmosphere and locks it up into organic molecules :
1. Identify two processes that break-down organic molecules
and return CO2 to the atmosphere: cellular respiration and
burning of fossil fuels
2. Identify one process that removes CO2 from the atmosphere
and locks it up into organic molecules : photosynthesis
1. What is the trend in [CO2] from 1960 to 2010?
2. Why does [CO2] decline in the spring and summer?
3. Why does [CO2] increase in the fall and winter?
1. What is the trend in [CO2] from 1960 to 2010? increase
2. Why does [CO2] decline in the spring and summer? ↑ photo. takes up CO2
3. Why does [CO2] increase in the fall and winter? ↓ photo., resp. continues
1. What is the relationship between [CO2] and average
global temperature?
1. What is the relationship between [CO2] and average
global temperature? As [CO2] ↑ so does temp
How can the abundance of food affect the survival
and reproduction of a species?
If the food resource (in this case caterpillars) abundance
peak does not match the timing when chicks need to be
fed, chicks are less likely to survive. The population of
the bird species is thus likely to decline.
Carbon & Organic Molecules
• 96% of the matter of your body is composed of:
____, ____, ____, ____
• 98+% includes:
____, ____, ____, ____, ____, _____
• Organic molecules have a ____-based skeleton
• Carbon forms ____ - covalent bonds
Carbon & Organic Molecules
• 96% of the matter of your body is composed of:
C, H, N, O
• 98+% includes:
CHNOPS
• Organic molecules have a C-based skeleton
• Carbon forms 4 - covalent bonds
1. Describe what is being shown in the diagram:
2. Name the process
1. Describe what is being shown in the diagram: A molecule
of water is lost as a monomer is added to a polymer
2. Name the process dehydration synthesis
1. Describe what is being shown in the diagram:
2. Name the process
1. Describe what is being shown in the diagram: A molecule
of water is added to break a monomer from a polymer
2. Name the process hydrolysis
1. Which reactant do the C atoms of glucose come from?
2. Which reactant do the O atoms of glucose come from?
3. Which reactant do the H atoms of glucose come from?
4. Which reactant does O2 gas come from?
1. Which reactant do the C atoms of glucose come from? CO2
2. Which reactant do the O atoms of glucose come from? CO2
3. Which reactant do the H atoms of glucose come from? H2O
4. Which reactant does O2 gas come from? H2O
4g
235,000 kg (235 million grams)
An acorn grows into a massive oak tree. There is a
massive increase in biomass. Where, exactly, did all
that matter (mass) come from?
4g
235,000 kg (235 million grams)
An acorn grows into a massive oak tree. There is a
massive increase in biomass. Where, exactly, did all
that matter (mass) come from?
C = 12x6=72
O = 16x6=96
CO2: 168 amu
H = 1x12=12
H2O: 12 amu
Most of the biomass comes from
CO2, a small amount also comes
from the Hydrogen atoms split
from H2O
LIGHT REACTIONS
H2O
co2
CALVIN CYCLE/
CARBON FIXATION
Light
NADP+
ADP
CHLOROPHYLL
P
THYLAKOID
STROMA
ATP
NADPH
O2
C6H12O6
1. Which organelle is
shown?
2. What process is
diagrammed?
3. Where do the
light reactions
occur?
4. Where does the
Calvin cycle
occur?
LIGHT REACTIONS
H2O
co2
CALVIN CYCLE/
CARBON FIXATION
Light
NADP+
ADP
CHLOROPHYLL
P
THYLAKOID
STROMA
ATP
NADPH
O2
C6H12O6
1. Which organelle is
shown?
chloroplast
2. What process is
diagrammed?
photosynthesis
3. Where do the
light reactions
occur? thylakoid
4. Where does the
Calvin cycle
occur? stroma
LIGHT REACTIONS
H2O
co2
CALVIN CYCLE/
CARBON FIXATION
Light
NADP+
ADP
CHLOROPHYLL
P
THYLAKOID
STROMA
ATP
NADPH
O2
C6H12O6
For the light
reactions:
1. Which reactant
enters?
2. Which product
leaves?
3. What happens to
the hydrogen
atoms?
4. What is light
energy
transformed into?
LIGHT REACTIONS
H2O
co
CALVIN CYCLE/
2 CARBON FIXATION
Light
NADP+
ADP
CHLOROPHYLL
P
THYLAKOID
STROMA
ATP
NADPH
O2
C6H12O6
For the light
reactions:
1. Which reactant
enters? H2O
2. Which product
leaves? O2
3. What happens to
the hydrogen
atoms? Carried by
NADPH
4. What is light
energy
transformed into?
Chemical energy:
NADPH and ATP
LIGHT REACTIONS
H2O
co2
CALVIN CYCLE/
CARBON FIXATION
Light
NADP+
ADP
CHLOROPHYLL
P
THYLAKOID
STROMA
ATP
NADPH
O2
C6H12O6
For the Calvin cycle:
1. Which reactant
enters?
2. Which product
leaves?
3. Where does the
ATP and NADPH
come from?
4. What is ATP and
NADPH used for?
LIGHT REACTIONS
H2O
co2
CALVIN CYCLE/
CARBON FIXATION
Light
NADP+
ADP
CHLOROPHYLL
P
THYLAKOID
STROMA
ATP
NADPH
O2
C6H12O6
For the Calvin cycle:
1. Which reactant
enters? CO2
2. Which product
leaves? C6H12O6
3. Where does the
ATP and NADPH
come from? The
light reactions
4. What is ATP and
NADPH used for?
Energy to build
glucose
When a person loses 5 lbs. of fat, where exactly does it go?
Cellular respiration:
Glycolysis occurs in the cytoplasm and does not
require oxygen gas: 6-C sugar (glucose) is split into
two 3-C pyruvate molecules, yielding 2 net ATP
6-C
3-C
2
3-C
2 pyruvate
molecules
Cellular Respiration
1. 6-C sugar (glucose) split into two 3-C pyruvate
2. If O2 is present, pyruvate moves into the
mitochondrion where it is fully broken down
3. High energy carbon-hydrogen bonds in fuel
molecules are broken – this energy is used to
pump H+ ions across the mitochondrion’s inner
membrane
4. When the H+ ions diffuse through ATP
synthase: ADP + Pi → ATP (ATP is recycled)
5. C in organic molecule C6H12O6 → CO2
6. H from glucose + O2 → H2O
Fermentation
1. What determines the route
of pyruvate after glycolysis?
2. What are two possible
products of fermentation?
3. Where does fermentation
occur?
4. Where does respiration
occur?
Fermentation:
2 ATP
5. How does ATP production
fermentation vs. cellular
respiration compare:
Respiration:
36 ATP
6. How does fermentation
relate to NADH?
Fermentation
Fermentation:
2 ATP
Respiration:
36 ATP
1. What determines the route of
pyruvate after glycolysis? + or oxygen
2. What are two possible products of
fermentation? Alcohol and lactic acid
3. Where does fermentation occur?
cytoplasm
4. Where does respiration occur?
mitochondrion
5. How does ATP production
fermentation vs. cellular respiration
compare: About 18 times more with
resp.
Alcoholic Fermentation
In the absence of oxygen (anaerobic)
+ 2 ATP
recycled
Enzymes
Glucose
Ethanol
(alcohol)
Represents a
lot of calories
Alcoholic
fermentation used in
brewing and winemaking
Carbon
dioxide gas
Energy and Exercise
3 sources of energy:
1. Use ATP already in muscles
(only enough for a few
seconds)
2. Use new ATP made from
lactic acid fermentation (only
for about 90 seconds)
3. Use new ATP made from
cellular respiration relies on
glycogen (animal-starch) stored
in muscles and the liver
Living Organisms are Open Systems
Organic molecules
(food) provides the
chemical building
blocks living things
need to grow and
reproduce
1. Digestive system breaks food down
2. Cell metabolism may further break down molecules
3. Cells use ATP energy to build new polymers from
monomers