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. H 2 O. B. NADP +. C. O 2. D. Glucose. E. ADP. 3. For the electron transport chain used in photosynthesis, the initial electron donor is, the final electron acceptor is, 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 FADH 2 ATP and NADPH Glucose Glucose NADH, ATP and Pyruvate NADH and FADH 2 Proton Gradient Proton Gradient ATP Pyruvate NADH and AcCoA Sunlight 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? 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. 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. 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 Membrane: Electron Donor: Complex I Complex II Light-Dependent Reactions 8. Which one of the following is a reduced coenzyme that is synethsized in the Light-Dependent Reactions? A. FADH 2 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: Carbon-Containing Product(s): Redox: Light-Independent Reactions Transition Step -oxidation Fermentation (in animals) Citric Acid Cycle Glycolysis 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. The membrane must be fluid to allow protein complexes to move. Electrons flow from a high energy state to a low energy state. A reduced coenzyme is produced. Energy is stored in a proton gradient. The electrons must pass through Complex IV.
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) Redox Calvin Cycle Citric Acid Cycle Fermentation (in animals) Glycolysis Transition Step Carbon-Containing Product(s) Redox 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 Process Citric Acid Cycle Electron transport from Photosystem II to Photosystem I Anaerobic Metabolism (in humans) ATP Synthase High-Energy Molecule(s) AFTER the Process Light-Independent Reactions 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 Water is reduced to form molecular oxygen. Mitochondria Chloroplasts Both A coenzyme is oxidized. Mitochondria Chloroplasts Both Protons are moved by active transport. Mitochondria Chloroplasts Both Electron transport relies on a functional antenna complex Energy is stored by making one compartment of an organelle more acidic. Mitochondria Chloroplasts Both Mitochondria Chloroplasts Both 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 Fermentation (in fungi or plants) Light-Independent Reactions Transition Step -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. stores energy in FADH 2 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: Glycolysis: Transition Step: -oxidation: Light-dependent reactions: 19. Classify each of the following reactions as an oxidation reaction, a reduction reaction, both or neither. NADP + NADPH Oxidation Reduction Both ADP + PO 4 ATP Oxidation Reduction Both Oxidation Reduction Both Pyruvate Ethanol + CO 2 Oxidation Reduction Both 4 H + + O 2 2 H 2 O Oxidation Reduction Both 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 Acetyl-CoA (AcCoA) C Citric Acid Cycle CO 2 D Deamination Ethanol E Glycolysis
Glucose F Light-Dependent Reactions 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? 22. Which complex (or complexes) is correctly described by each of the statements below? List all that apply. A ATP Synthase B Complex I Releases low energy electrons to O 2. Can transport protons against their diffusion gradient. Located in the thylakoid membrane. Contains chlorophyll. Oxidizes FADH 2. C Complex II D Complex III E Complex IV F Cytochrome Complex G Photosystem I H Photosystem II I None of these