Quiz for Chapter 11 & 12

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1. Paracrine signaling
A) involves secreting cells acting on nearby target cells by discharging a local regulator into the extracellular fluid. B) requires nerve cells to release a neurotransmitter into the synapse. C) occurs only in paracrine yeast cells.

D) has been found in plants but not animals.
E) involves mating factors attaching to target cells and causing production of new paracrine cells. 2. Which of the following is true of synaptic signaling and hormonal signaling? A) Hormonal signaling occurs in animals only.

B) Hormonal signaling is important between cells that are at greater distances apart than in synaptic signaling. C) Both act on target cells by a G-protein-signaling pathway. D) Only A and B are true.

E) A , B, and C are true.

3. From the perspective of the cell receiving the message, the three stages of cell signaling are A) the paracrine, local, and synaptic stages.
B) signal reception, signal transduction, and cellular response C) signal reception, nucleus disintegration, and new cell generation. D) the alpha, beta, and gamma stages.
E) signal reception, cellular response, and cell division.

4. When a cell releases a signal molecule into the environment and a number of cells in the immediate vicinity respond, this type of signaling is A) typical of hormones.
B) autocrine signaling.
C) paracrine signaling.
D) endocrine signaling.
E) synaptic signaling.

5. The yield from putting NADH + H+ through the electron transport chain is ________ ATP and the yield from FADH2 is ________ ATP. A. three, two
B. three, four
C. four, three
D. two, three

6. Fermentation takes place in the ________ of oxygen, a process also known as ________ respiration. A. presence, aerobic
B. presence, anaerobic
C. absence, aerobic
D. absence, anaerobic

7. Pyruvate is the starting compound for ________.
A. Alcohol fermentation
B. Glycolysis
C. Lactic acid fermentation
D. All of the answers are correct
E. Alcohol fermentation and lactic acid fermentation

8. ________ is the key regulatory enzyme of the glycolytic pathway. A. Hexokinase
B. Rubisco
C. Phosphofructokinase
D. Isomerase

9. What is the role of O2 in electron transport?
final electron acceptor

10. What are the three stages of cellular respiration and which one contributes most to ATP yield? Glycolysis, the citric acid cycle and oxidative phosphorylation/electron transport. Oxidative phosphorylation contributes most.

11. Describe the importance of the membrane in electron transport. Provides a ‘substrate’ for the proteins involved; support, positioning relative to each other, etc. Provides a barrier across which protons can be pumped to form a gradient that is later used to form ATP.

12. What pathway is common to both aerobic and anaerobic respiration? Glycolysis

13. What is the key regulatory enzyme of glycolysis and what is the effect of an increased ATP concentration on this enzyme and on respiration in general? The key regulatory enzyme of glycolysis is phosphofructokinase. An increase in ATP concentration means that the cell is not using all the energy that is being produced from the breakdown of glucose. Therefore, phosphofructokinase is shut down to prevent unnecessary breakdown of energy stores (i.e. glucose). Respiration will slow down.

14. What is the primary difference (in general terms) between substrate-level phosphorylation and oxidative phosphorylation? substrate-level phosphorylation involves the transfer of a phosphate group from one molecule to another and oxidative phosphorylation involves the formation of ATP as a result of redox reactions in the electron transport chain.

15. What is the name of the enzyme that uses the proton gradient to make ATP? Answer: ATP synthase

Objective 2-4

16. A type of local regulation in which only the adjacent cells are...
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