Sample Questions Exam II, BIOL 3090

  1. SRP receptors are located in the

    2. a). plasma membrane

    b). cytoplasm

    c). nucleus

    d). endoplasmic reticulum

  2. which is a major protein of the erythrocyte cytoskeleton

    3. a). ankyrin

    b). glycophorin

    c). myosin

    d). spectrin

  3. chaperones are usually involved in

    4. a). protein glycosylation

    b). protein folding

    c). protein phosphorylation

    d). golgi vesicle transport

  4. Proteins targeted to the mitochondria are made on

a). ribosomes bound to the mitochondria

b). ribosomes bound to the ER

c). ribosomes bound to the golgi

d). ribosomes free in the cytoplasm

5. The phosphocholine portion of phosphatidylcholine is: Indicate all answers that are correct.

a). the amphipathic part of the molecule

b). the hydrophobic part of the molecule

c). the hydophilic part of the molecule

d). the micelle

e). the head group

6. spectrin is:

a). is an integral membrane protein

b). is a glycoprotein

c). helps to maintain the shape and integrity of erythrocytes.

d). binds to plasma membrane proteins through ankyrin and the 4.1 protein.

e). shuttles O2 in for CO2

7. The thick filament of the sarcomere is made of:

a). myosin I

b). myosin II

c). myosin V

d). actin

e). tropomyosin

8. Which of the following best describes the movement of proteins from one compartment of the Golgi to another?

a). they move by diffusion between adjacent compartments

b). they are carried in clathrin-coated vesicles

c). they are carried in coatomer-coated vesicles

d). they are carried in actin-coated vesicles

e). they move between compartments using a microtransporter (as seen in STAR TREK)

  1. A microfilment motor protein is:

    2. a). actin

    b). myosin

    c). kinesin

    d). tropmyosin

  2. The ATP binding site of myosin is located in the

    3. a). head

    b). Neck

    c). shoulder

    d). tail

  3. Which part of the nerve cell is used to receive signals?

    4. a). the cell body

    b). the axon termini

    c). the dendrites

    d). the axon

  4. In rod cells in the dark _____.

    5. a). the cAMP level is high

    b). the cAMP level is low

    c). the cGMP level is high

    d). the cGMP leel is low

  5. How do voltage gated channels detect changes in the membrane potential?

14. How does the Na+/K+ ATPase generate a membrane potential?

15. In some animal cells glucose is transported into the cell along with a Na+. The glucose concentration inside the cells is higher than outside. For this type of transport to work what must the Na+ concentration be outside the cell in comparison to inside the cell? What kind of transport is this?

16. How does the animal cell maintain a Na+ gradient across the plasma membrane?

17. What is the signal that directs a protein to the peroxisome?

  1. How many signal sequences and stop-transfer sequences does the following protein have? Has this protein had a signal sequence removed or not?

A protein in the golgi membrane has three transmembrane helices. The N terminal amino acid is in the golgi lumen and the C-terminal amino acid is in the cytosolic side of the membrane.

19. Describe the differences between insulin, proinsulion and preproinsulin.

ANSWERS

Answers to questions in the chapters.

Chapter 15, 4. a, 6. d, 7. A, 11. B, 12. D, 13. A

Chapter 17, 1. b, 2. c, 3. a, 4. d, 5. d, 6. c, 7. b, 8. d, 9. a, 10. c, 11. d, 12. b, 13. a, 14. c

Chapter 21, 1. D, 2. D, 3. A, 4. C, 11. A, 12. C, 13. C

Chapter 18, 1. D, 2. B, 3. B, 5. D, 6. B, 7. A, 8. B, 9. C, 11. B, 12. D, 13. C, 14. D, 15. c

Answers to sample questions.

1. d, 2. D, 3. B, 4. D, 5. C & E, 6. C and D are good answers 7. B, 8. C, 9. B, 10. A, 11. C, 12. c

13.  They have charged helices within the membrane that move in response to the potential across the membrane.

14. It pumps three Na+ out for every two K+ ions in.  A net of one + charge out of the cell.

15. The Na+ concentration outside the cell must be higher for this to work. This is cotransport.

16. The operation of the Na+ - K+ ATPase.  Note that ATP is required.

17. A amino acid sequence of S-K-L at or very near the C-terminus.

18.  It had two ER-signal sequences and two stop-transfer sequences. The N-terminal ER signal sequence was removed.

19.  Insulin must be activated by proteolysis in the golgi and the correct disulfides need to be formed.  Insulin is the final active protein.  Proinsulin is the protein after it has been put in the ER but it has not been processed.  Preproinsulin is the proinsulin + the signal sequence.  This is what the ribosome actually translates.  The signal sequence is removed as it enters the ER to form proinsulin.