BIO 130 2016-VERSION33

BIO 130 2016-VERSION33 1. Which of the following statements best describes the cell wall? a. The cell wall is only present in plant cells. b. The cell wall is only present in prokaryotes. c. The cell wall is present in some single celled organisms. d. The cell wall is present in some multicellular animal cells. 2. Data from a FRAP experiment is shown below. Which of the following data curves best represents the protein that is LEAST mobile within the lipid bilayer? a. (i.) b. (ii.) c. (iii.) d. (i.), (ii.), and (iii.) are equally mobile. 3. You are analyzing plasma membranes, and have discovered a new type of phospholipid that is located on the leaflet that faces extracellular space. Where would be a logical place to look for this new phospholipid? a. On the side of the inner nuclear membrane that faces the inside of the nucleus. b. On the cytosolic face of vesicles. c. On the matrix-facing leaflet of the inner mitochondrial membrane. d. On the exoplasmic face of the golgi apparatus membrane. 4. Which of the following statements is correct? a. In a cell, phospholipids are synthesized on the cytosolic leaflet of the endoplasmic reticulum, and never move to the exoplasmic leaflet. b. In order to extract peripheral membrane proteins, one must destroy the phospholipid membrane. c. Amphipathic alpha helices typically exist as transmembrane proteins. d. Some transmembrane proteins do not have any alpha helices. 5. Which of the following includes ribosomes? i. cytoplasm ii. cytosol iii. lumen a. (i) only b. (i) and (ii) only c. (ii) only d. (i), (ii), and (iii) only 6. Which of the following membrane proteins most likely corresponds to the hydropathy plot shown below? Assume that the grey box is a phospholipid membrane. “N” represents the N-terminus, and “C” represents the C-terminus. 7. A summer student has performed a modified FRAP experiment using a cell with a high number of GFP- fused GPI-anchored proteins. Which of the following would cause the largest decrease in fluorescence recovery time (after photobleaching)? a. Increasing cholesterol concentration in the phospholipid membrane. b. Decreasing the fatty acid tail length of the phospholipids in the membrane. c. Increasing the saturation of the phospholipid hydrocarbon tails in the membrane. d. Switching phosphatidylcholine to phosphatidylethanolamine. 8. Which of the following proteins use/uses passive transport? a. The GLUT uniporter. b. The Na+/H+ exchanger. c. The Na+/K+ Pump. d. Both A and B are correct. 9. You have identified a patient that contains abnormal intestinal epithelia. All the proteins are properly distributed except for the GLUT2 uniporter. This transport protein is present on both the apical and basolateral surfaces. Which of the following would be most likely observed in the patient? a. An increased ability to absorb glucose from the intestinal lumen; possibly higher blood glucose. b. A decreased ability to absorb glucose from the intestinal lumen; possibly lower blood glucose. c. A nonfunctioning Na+/glucose symporter; possibly lower blood glucose. d. A nonfunctioning Na+/glucose symporter; possibly higher blood glucose. 10. Which of the following best completes the statement below? “Cells placed in a solution will .” a. isotonic; swell b. hypertonic; swell c. hypertonic; shrink d. hatotonic; shrink 11. A particular cell contains the Na+/glucose symporter and the Na+/H+ exchanger in its plasma membrane. There is a higher concentration of Na+ and H+ in the extracellular space, and a higher concentration of glucose within the cytosol. Which of the following will allow the Na+/glucose symporter to continue functioning for the longest amount of time? a. Adding more H+ to extracellular space. b. Adding more Na+ into the cytosol. c. Adding a chemical that inhibits Na+/H+ exchangers. d. Adding a chemical that inhibits the Na+/K+ pump. 12. Which of the following best describes the sequence of events in a postsynaptic membrane that experiences a nerve impulse? The activation of…. a. chlorine ion-gated channels followed by ion-gated channels. b. ligand-gated ion channels followed by voltage-gated ion channels. c. voltage-gated ion channels followed by ion-gated ion channels. d. chlorine ion-gated channels followed by voltage-gated ion channels. 13. A research student is working in a membrane potential lab and remembers that the animal cell resting membrane potential varies from -20 mV to -120 mV. If she would like to make the membrane potential more positive, which one of the following steps should she take? a. Add Cl- to the cytosol. b. Add Na+ to the extracellular space. c. Add chemicals that increase the activity of the Na+/K+ ATPase and K+ leak channel. d. Add chemicals that inhibit the Na+/K+ ATPase and K+ leak channel. 14. Which of the following statements concerning the pumping cycle of the Na+/K+ pump is the most accurate? a. In the E2 conformation, the pump is bound to cytosolic ATP. b. The pump requires 2 molecules of ATP for every 3 Na+ and 2 K+ transported. c. In the E1 conformation, extracellular ATP is bound to the pump, along with 3 Na+. d. The E1 conformation is followed by pocket closure and ATP hydrolysis. 15. Which of the following would be the LEAST likely to occur? a. A protein moving from the endoplasmic reticulum lumen to the cytosol. b. A protein moving from the golgi apparatus lumen to the endoplasmic reticulum lumen. c. A protein moving from a secretory vesicle to the golgi apparatus. d. A protein moving from the cytosol to a chloroplast. 16. A pulse chase experiment was performed with radioactive amino acids. Most of the radioactivity was observed in the cytosol after 120 min. Which of the following explanations is most likely correct? a. The cells make a large proportion of cytosolic proteins. b. Pancreatic cells were used in this experiment. c. The cells require specific stimuli to activate their secretory vesicles. d. This observation is impossible because all eukaryotic cells have a constitutive secretory pathway. 17. Which of the following proteins will most likely be found in the membrane of the golgi apparatus? (“START” refers to an ER signal sequence, “++” refers to a positively charged amino acid region, “--“ refers to a negatively charged amino acid region.) 18. A scientist is studying a specific lysosomal hydrolase, and identifies a variant that has its N-terminal signal sequence deleted. Where would this protein variant most likely be located? a. In the lysosome lumen. b. In the cytosol. c. In the vesicle lumen. d. In the endoplasmic reticulum lumen. 19. The release of acetylcholine upon calcium influx is an example of which of the following? a. Oxidative synthesis. b. Endocytosis. c. Constitutive secretion. d. Regulated secretion. 20. In order to track the protein shown below, you have taken its DNA sequence and altered it so that it encodes for GFP-fused protein. The GFP is fused to the C-terminal end of the protein. Where will you find the GFP in the cell? (“START” refers to an ER signal sequence, “++” refers to a positively charged amino acid region, “--“ refers to a negatively charged amino acid region.) a. In the cytosol. b. In the endoplasmic reticulum lumen. c. Free floating in the cell exterior. d. In mitochondria. 21. Which of the following is located on the outer mitochondrial membrane? a. TIM 22 complex b. TIM 23 complex c. TOM complex d. Toc complex 22. Which of the following is most likely bound to γ-tubulin in a very long microtubule that extends from the cell body to the axon terminus of a nerve cell? a. α-tubulin. b. Kinesin. c. β-tubulin. d. Dynein. 23. Which of the following can be bound to actin filaments? a. Centrosomes. b. Hemidesmosomes. c. Adherens junctions. d. Desmosomes. 24. Which of the following is a similarity between microfilaments and microtubules? a. They are both composed of heterodimers. b. They both require ATP for assembly. c. They are both hollow cylinders. d. They are both composed of protofilaments. 25. Which of the following statements best describes the actin filament ATP cap? It is only composed of… a. radioactively-labeled actin bound to ATP, and moves with treadmilling. b. T form heterodimers, and conversion to D form will cause destabilization. c. T form monomers, but it is composed of different molecules over time. d. actin monomers with a cap of ATP molecules at the plus end.