BIOS 1700
Dr. Tanda
6 October 2016
Week 7, Session 3
Review:
1. Which of the following stages of respiration does not take place within the mitochondria?
- Glycolysis
- Acetyl-coA synthesis
- Citric acid cycle
- Electron transport chain
- All of the above stages occur within the mitochondria
2. Energy from the photosynthetic electron transport chain in the form of NADPH feed into the Calvin cycle at which stage?
a. Carboxylation
b. Reduction
c. Regeneration
d. Rubisco activation
3. What function do antenna chlorophyll molecules perform?
a. Strip electrons from water molecules to start the ETC
b. Transfer light energy to other antenna chlorophyll molecules
c. Pass electrons to reaction center chlorophyll
d. All of the above
4. Which of the following is not a difference between the respiratory and photosynthetic ETC?
- Only the respiratory ETC is used to pump H+ and form an electrochemical gradient
- Oxygen is the final e- acceptor in the respiratory ETC, but it is produced by the photosynthetic ETC
- NADH donates e- to the respiratory ETC, but NADP+ accepts e- at the end of the photosynthetic ETC
5. Photorespiration, the accidental addition of O2 to RuBP instead of CO2, results in what problem(s) for the cell?
- Loss of carbon in the form of co2
- Waste of energy in the form of ATP
- Production of ROS
- Both a and b
- All of the above
6. In cell communication, which one of the following is a requirement of the responding cell?
a. It must be eukaryotic cell
b. It must produce signaling molecules
c. It must have receptor proteins that are specific for the ligand
d. It must express MAP kinase
7. You examine a cell that has a high level of activity of the enzyme PFK-1. This cell is likely to have:
- A high level of ATP
- A high level of citrate
- A high level of ADP
- B and C
- All of the above
In the metabolic pathway illustrated below, the starting material (substrate A) is converted equally to one of two end products, E or G. Use the diagram of the pathway below to answer the following questions. Letters indicate the substrates and products, and numbers indicate the enzymes. In this pathway, the intermediate, C, is a substrate for both enzyme 3 and enzyme 5 and is converted with equal efficiency to D and F.
8. If end product E inhibits enzyme 1, which of the following would you expect to observe?
a. an increase in the production of G
b. a decrease in the production of E, but no change in the production of G
c. a decrease in the production of E and G
d. an increase in the production of A
In the metabolic pathway illustrated below, the starting material (substrate A) is converted equally to one of two end products, E or G. Use the diagram of the pathway below to answer the following questions. Letters indicate the substrates and products, and numbers indicate the enzymes. In this pathway, the intermediate, C, is a substrate for both enzyme 3 and enzyme 5 and is converted with equal efficiency to D and F.
9. If end product G inhibits enzyme 5, which of the following would you expect to observe as the amount of G increases in the cell?
a. an increase in the production of C.
b. an increase in the production of B
c. an increase in the production of E
d. a decrease in the production of D
e. an increase in the production of G
10. Very low concentrations of detergent make membranes leaky to small molecules and ions without damaging proteins. In isolated mitochondria exposed to detergent, the molecules of the electron transport chain and of ATP synthase remain intact. Do you expect ATP synthesis to continue in the presence of low concentrations of detergent?
a.Yes, because all enzymes and electron carriers are functional.
b. No, because with a leaky membrane, the proton gradient cannot be maintained.
c. No, because leaky membranes do not allow NADH and FADH2 to donate their electrons to the electron transport chain.
d. No, because leaky membranes inhibit glycolysis.
11. Oligomycin is an antibiotic that binds ATP synthase, blocking the flow of protons through the enzyme's proton channel. In addition to preventing synthesis of ATP, what additional effect might you expect in response to the presence of oligomycin?
a. higher pH in the intermembrane space
b. lower pH in the intermembrane space
c. a buildup of protons in the mitochondrial matrix
Chapter 9:
12. What are four elements required for cell communication? Use a drawing to answer this question.
13. What’s a signaling molecule?
14. What are the four steps in cell signaling? Explain each step.
15.Draw and describe the four different types of cell communication.
16. What is the difference between serum and plasma?
17. Do cells grow faster in the presence of serum or in the presence of plasma? What stimulant is in serum or plasma that stimulates cell division?
18. Compare hydrophilic ligands and hydrophobic ligands. Give an example of each.
19. Draw a cell with a cell-surface receptor. Would this be a hydrophilic ligand or a hydrophobic ligand? Draw a cell with an intracellular receptor. Would this be a hydrophilic ligand or a hydrophobic ligand?
20. What are the three common types of cell-surface receptors? Describe each.
21. ______remove phosphates.
22. ______add phosphates.