Download Bio102 Problems

Bio102 Problems
Photosynthesis
1. Why is it advantageous for chloroplasts to have a very large (in surface area) thylakoid membrane
contained within the inner membrane?
A. This limits the amount of stroma volume, keeping the concentrations of enzymes and substrates
very high.
B. This allows faster passive transport of small carbohydrates.
C. This allows the organelle to have more copies of photosystems I and II and ATP synthase.
D. The larger membrane improves its fluidity.
E. This makes a more effective barrier to prevent protons from leaking through.
2. At the end of the electron transport chain found in the thylakoid membrane, the electrons are
transferred to a molecule of
A. H2O.
B. NADP+.
C. O2.
D. Glucose.
E. ADP.
3. For the electron transport chain used in photosynthesis,
the initial electron donor is __water________________,
the final electron acceptor is __NADP+___________,
and the electron has gained/lost energy during transport.
4. Identify the metabolic process (such as fermentation,  -oxidation, etc.) that transfers energy from
the molecule(s) listed in the column on the left to the molecule(s) listed in the column at right. List
only one process in each empty box.
AcCoA
ATP, NADH and FADH2
Citric Acid Cycle
Calvin-Benson Cycle
ATP and NADPH
Glucose
(or Light-Independent Reactions)
Glucose
NADH and FADH2
Proton Gradient
Pyruvate
Sunlight
Glycolysis
Electron Transport
Chemiosmosis
Transition Step
Light-Dependent Reactions
NADH, ATP and Pyruvate
Proton Gradient
ATP
NADH and AcCoA
NADPH and ATP
5. 2-carboxyarabinitol-1,5-bisphosphate (CABP) is an inhibitor of the Calvin cycle.
5A. Which one of the following enzymes might CABP inhibit?
A. Hexokinase
B. ATP synthase
C. Citrate oxidase
D. RuBisCo
E. Pyruvate decarboxylase
5B. Why does treating chloroplasts with CABP eventually also cause the light-dependent
reactions of photosynthesis to cease?
NADP+ can’t be regenerated without the Calvin cycle.
6A.
A drawing of a chloroplast is shown below. Draw an arrow that points to the compartment
where the light-independent
reactions of photosynthesis
occur and write the name of
this compartment below.
Stroma
6B. During the light-dependent
reactions of photosynthesis,
protons (H+) are actively
transported across a
membrane. Draw a star in the compartment that becomes more acidic and write the name of that
compartment below.
Thylakoid Lumen
7. Each of the following three proteins or processes resides in a membrane and transports electrons.
For each, identify the specific membrane where it is found and identify the molecule that donates
the electrons to be transported.
*
Protein or Process
Complex I
Complex II
Light-Dependent
Reactions
Membrane:
Mitochondrial Inner
Membrane
Mitochondrial Inner
Membrane
Electron Donor:
Thylakoid Membrane
Water
NADH
FADH2
8. Which one of the following is a reduced coenzyme that is synethsized in the Light-Dependent
Reactions?
A. FADH2
B. FAD
C. NADP+
D. NADPH
E. NADH
F. NAD+
9. In a plant cell, where do the Light-Independent Reactions occur?
A. Stroma
B. Cytosol
C. Matrix
D. Intermembrane Space (IMS)
E. Thylakoid Lumen
10. Name the carbon-containing molecule(s) that result from each of the following processes. Also
indicate if these carbon atoms are being oxidized, reduced or neither in these processes.
Process:
Light-Independent
Reactions
Transition Step
-oxidation
Fermentation
(in animals)
Citric Acid Cycle
Glycolysis
Carbon-Containing Product(s):
Redox:
Glucose
ox. red. neither
Acetyl-CoA
Acetyl-CoA
ox. red. neither
Lactate
ox. red. neither
CO2
Pyruvate
ox. red. neither
ox. red. neither
ox. red. neither
11. Indicate whether each of the following statements describes electron transport on the mitochondrial
inner membrane (MIM) or the light-dependent reaction of photosynthesis on the thylakoid
membrane (TM) or both or neither by circling your choice.
The initial electron donor is a water
molecule.
MIM
TM
both
neither
The membrane must be fluid to
allow protein complexes to move.
MIM
TM
both
neither
Electrons flow from a high energy
state to a low energy state.
MIM
TM
both
neither
A reduced coenzyme is produced.
MIM
TM
both
neither
Energy is stored in a proton
gradient.
MIM
TM
both
neither
The electrons must pass through
Complex IV.
MIM
TM
both
neither
12. For each process listed below, identify the coenzyme (or coenzymes) that are required. Then
indicate if the coenzyme(s) is oxidized, reduced or neither. Similarly, identify the carboncontaining molecule that is produced by the process and indicate if those carbon atoms have been
oxidized, reduced or neither during the process.
Process
Coenzyme(s)
Calvin Cycle
NADPH
Citric Acid
Cycle
NADH, FADH2
Fermentation
NADH
(in animals)
Glycolysis
NADH
Redox
Oxidized
Reduced
Neither
Oxidized
Reduced
Neither
Oxidized
Reduced
Neither
Oxidized
Reduced
Neither
Carbon-Containing
Product(s)
Glucose
CO2
Lactate
Pyruvate
Redox
Oxidized
Reduced
Neither
Oxidized
Reduced
Neither
Oxidized
Reduced
Neither
Oxidized
Reduced
Neither
Transition
Step
Oxidized
Reduced
Neither
NADH
Oxidized
Reduced
Neither
Acetyl-CoA
13. Metabolic pathways represent a mechanism to transform energy from one source to another. For
each of the following processes, identify the high-energy molecule (or molecules) present both before
and after the process.
High-Energy Molecule(s)
BEFORE the Process
Acetyl-CoA
light
Glucose
Proton Gradient
NADPH, ATP
Process
Citric Acid Cycle
Electron transport from
Photosystem II to Photosystem I
Anaerobic Metabolism
(in humans)
ATP Synthase
Light-Independent Reactions
High-Energy Molecule(s)
AFTER the Process
NADH, FADH2
electron
ATP, Lactate
ATP
Glucose
14. Which one of the following is a key enzyme in photosynthesis?
A. AMPK
B. RuBisCo
C. PFK
D. Hexokinase
E. Citrate Synthase
15. For each statement below, indicate if it is true for electron transport that happens in mitochondria,
electron transport that happens in chloroplasts, both or neither by circling your choice.
The electron transport chain is located on the
Inner Membrane.
Mitochondria
Chloroplasts
Both
Neither
Water is reduced to form molecular oxygen.
Mitochondria
Chloroplasts
Both
Neither
A coenzyme is oxidized.
Mitochondria
Chloroplasts
Both
Neither
Protons are moved by active transport.
Mitochondria
Chloroplasts
Both
Neither
Electron transport relies on a functional antenna
complex
Mitochondria
Chloroplasts
Both
Neither
Energy is stored by making one compartment of an
organelle more acidic.
Mitochondria
Chloroplasts
Both
Neither
16. Follow the Carbon! For each process listed below, list what carbon containing compound(s) are
put in and what carbon containing compound(s) come out. Also indicate the relative numbers for each
process except  -oxidation. The first one is done as an example.
Input
Process
Output
Glucose
Glycolysis
2 Pyruvate
Citric Acid Cycle
CO2
Fermentation
(in fungi or plants)
Ethanol + CO2
Light-Independent Reactions
Glucose
Transition Step
AcCoA + CO2
AcCoA
Pyruvate
CO2
Pyruvate
Fatty acids
-Oxidation
17. Name one process or pathway that stores energy in each of the following molecules. Notice that
there may be more than one correct answer for each blank; just choose any one that is correct.
_______Citric Acid Cycle_________
________Glycolysis__________
__________ Electron Transport____
__________ Transition Step ______
__ Light-Dependent Reactions____
____ Light-Independent Reactions _
_______ Citric Acid Cycle ________
_______ Citric Acid Cycle ________
stores energy in FADH2
stores energy in ATP
stores energy in a H+ gradient
stores energy in AcCoA
stores energy in NADPH
stores energy in Glucose
stores energy in NADH
stores energy in GTP
18. List the high-energy molecules that are produced by each of the following processes. There may be
more than one correct answer; list all that apply. It is not necessary to list the number of each molecule formed.

Citric Acid Cycle: NADH, FADH2, ATP

Glycolysis: ATP, NADH, Pyruvate

Transition Step: NADH, AcCoA

-oxidation: AcCoA, NADH

Light-dependent reactions: NADPH, ATP
19. Classify each of the following reactions as an oxidation reaction, a reduction reaction, both or
neither.
NADP+ → NADPH
Oxidation
Reduction
Both
Neither
ADP + PO4 → ATP
Oxidation
Reduction
Both
Neither
Oxidation
Reduction
Both
Neither
Pyruvate → Ethanol + CO2
Oxidation
Reduction
Both
Neither
4 H+ + O2 → 2 H2O
Oxidation
Reduction
Both
Neither
20. For each carbon-contain molecule listed on the left, indicate which pathway (or pathways) in
which it is produced. List all that apply.
A Alcoholic Fermentation
B -Oxidation
__B I______
Acetyl-CoA (AcCoA)
C Citric Acid Cycle
__A C I____
CO2
D Deamination
__A_______
Ethanol
E Glycolysis
__G_______
Glucose
F Light-Dependent Reactions
__E_______
Pyruvate
G Light-Independent Reactions
H Receptor-Mediated Endocytosis
I Transition Step
21.
It’s obvious that the Light-Independent Reactions of photosynthesis can’t continue without the
high-energy molecules produced by the Light-Dependent Reactions. But would it be possible for the
Light-Dependent Reactions to continue if the Light-Independent Reactions were blocked? Why or why
not?
No. If the light-dependent reactions were blocked, NADPH can’t be recycled to NADP+.
Without NADP+, the electrons have no where to go in the light-dependent reactions thus
causing them to shut down.
22. Which complex (or complexes) is correctly described by each of the statements below?
List all that apply.
A ATP Synthase
B Complex I
__E________
Releases low energy electrons to O2.
C Complex II
__B D E F__
__A F G H__
__G H_____
___C_______
Can transport protons against their
diffusion gradient.
D Complex III
Located in the thylakoid membrane.
E Complex IV
Contains chlorophyll.
F Cytochrome Complex
Oxidizes FADH2.
G Photosystem I
H Photosystem II
I None of these