Flashcard
Which statement is true concerning catabolic pathways?
Answer: B — They supply energy, primarily in the form of ATP, for the cell's work.
2. Which statement is true for all exergonic reactions?
Answer: B — The reaction proceeds with a net release of free energy.
3. Which statement is true of enzymes?
Answer: E — All of the answers are true.
4. A chemical reaction that has a positive ΔG is described as:
Answer: A — Endergonic.
Matching – Section 3.3
5. Anabolic pathways
Answer: C — Consume energy to build polymers from monomers.
6. Catabolic pathways
Answer: B — Release energy by breaking down polymers to monomers.
7. First law of thermodynamics
Answer: D — Energy cannot be created or destroyed.
8. Second law of thermodynamics
Answer: A — Every energy transfer increases the entropy of the universe.
Chapter 8 – Figure 8.1
9. Which labeled energy measurement represents the activation energy for the enzyme-catalyzed reaction?
Answer: B — b.
Chapter 9
10. What happens during the cellular respiration reaction involving glucose and oxygen?
Answer: A — Glucose is oxidized and O₂ is reduced.
Matching – Section 3.3
11. O₂
Answer: C — Final electron acceptor in cellular respiration.
12. C₆H₁₂O₆
Answer: A — Source of electrons in cellular respiration.
13. Feedback inhibition
Answer: D — The end product of a metabolic pathway inhibits an earlier step.
14. Active site
Answer: B — Part of the enzyme involved in the catalytic reaction.
15. The oxygen consumed during cellular respiration is directly involved in which of the followingprocesses or events?
Answer: B. Accepting electrons at the end of the electron transport chain.
16. Where does glycolysis take place in eukaryotic cells?
Answer: A. Cytosol.
17. The molecule that functions as the reducing agent (electron donor) in a redox or oxidation-reduction reaction _____?
Answer: D. Loses electrons and loses potential energy.
18. Which metabolic pathway is common to both cellular respiration and fermentation?
Answer: C. Glycolysis.
19. Which of the following produces the most ATP when glucose is completely oxidized to carbondioxide and water?
Answer: E. Oxidative phosphorylation.
20. Phosphofructokinase is an allosteric enzyme that catalyzes the conversion of fructose6-phosphate to fructose 1,6-bisphosphate. If oxygen is present, an increase in the amountof ATP in a cell would be expected to _____?
Answer: A. Inhibit the enzyme and thus slow the rates of glycolysis and the citric acid cycle.
1. Which of the following equations properly summarizes photosynthesis?
Answer: C.
6CO2+6H2O+sunlight→C6H12O6+6O2
6CO
2
+6H
2
O+sunlight→C
6
H
12
O
6
+6O
2
2. What is the source of the extra ATP molecules consumed by the Calvin cycle?
Answer: C. Cyclic electron flow.
3. CO₂
Answer: B. Fixed into sugars during the Calvin cycle.
4. O₂ and electrons
Answer: D. Provided by the splitting of water in photosynthesis.
5. ATP and NADPH
Answer: C. Products of the light reactions that are then used by the Calvin cycle.
6. RuBisCO
Answer: A. Enzyme beginning the Calvin cycle and the most abundant protein in the universe.
7. Where in a plant cell does the Calvin cycle take place?
Answer: A. Stroma of the chloroplast.
8. Which sequence correctly represents the flow of electrons during photosynthesis?
Answer: B. H₂O → NADPH → Calvin cycle.
9. What two colors of light drive most of photosynthesis?
Answer: C. Red and blue.
11. A type of local regulation in which only adjacent cells are affected by a signal is called_____ signaling.
Answer: Paracrine signaling.
12. Which of the following is the best explanation for why most transduction pathways havemultiple steps?
Answer: Multiple steps allow amplification of the signal.
13. A(n) _____ is a small, non-protein molecule that functions in a transduction pathway.
Answer: C. Second messenger.
14. Protein kinase is an enzyme that functions in which of the following ways?
Answer: C. Activates substrate proteins by adding a phosphate group to them.
15. Ligand-gated ion channel
Answer: C. Binding of a signaling molecule to this receptor leads directly to a change in the distributionof ions on one side of its membrane.
16. Receptor tyrosine kinases
Answer: D. Activation of this receptor type is characterized by dimerization and phosphorylation.
17. cAMP
Answer: A. Acts as a second messenger in a signal transduction pathway.
18. Phosphodiesterase
Answer: B. Adenylyl cyclase has the opposite effect on this enzyme.
19. The receptors for steroid (lipid-soluble) hormones are located inside the cell. How do steroidsactivate these receptors?
Answer: C. Steroid hormones are lipid soluble, so they can readily diffuse through the cell membrane.
20. _____ is a second messenger that is actively pumped out of the cytosol, keeping itsconcentration low.
Answer: B. Ca²⁺ (calcium ions).