Unformatted text preview: Exam I Green
BIOL 3030 Cell Biology
1. Glycosylation involves the addition of carbohydrates to which region of a protein
2. Organelles with two lipid bilayers include all of the following, except:
3. Endosomes deliver extracellular material to which degradative vesicle?
d. COPI vesicle
4. The class of pumps that maintain acidic pH within organelles such as the lysosome is
b. P class ATP pump
c. V class ATP pump
d. F class ATP pump
5. A motif found in many proteins that bind RNA or DNA is
a. helix-loop-helix motif
b. tyrosine phosphorylation motif
c. coiled coil motif
d. zinc-finger motif
6. There are two major classes of chaperones that regulate protein folding in cells. Molecular
chaperones, such as Hsp70, bind to
a. unfolded proteins
b. proteins that have folded into their tertiary structure
c. multiprotein complexes
7. Which statement concerning protein modification is CORRECT?
a. Ubiquitin is covalently linked to proteins
b. Allosteric effects on proteins always work like molecular switches.
c. Protein phosphorylation is a type of irreversible covalent modification.
d. Proteolytic cleavage inactivates the target proteins. 1 8. About membrane transport, which statement is WRONG?
a. There is a Vmax for uniport transporters.
b. The energy required for membrane transport can come from ATP or electrochemical
c. Water as a small molecule is highly permeable through biomembranes.
d. Symporters and antiporters both utilize the energy stored in the concentration gradient
of a transport molecule.
9. The class of ATP-powered transporters that moves lipid molecules from one leaflet to the
a. P class
b. V class
c. F class
10. Potassium can cross cell membranes by passive diffusion.
11. The membrane-bound organelle that is involved in degradation of proteins taken up by the
c. endocytic vesicle
e. endoplasmic reticulum
12. Lysosomes are involved in degrading cellular structures such as old organelles. The name
for this process is
13. The macromolecular machine that recognizes ubiquitinated proteins and degrades them into
7-8 amino acid peptide is called
14. Enzymes increase the rate of a reaction by
a. lowering the activation energy
b. increasing the “effective” substrate concentration
c. raising the activation energy
d. inducing formation of a quaternary structure 2 15. Multidrug resistance protein (MDR1) belongs to what class of transporter?
b. V class ATP pump
c. ABC transporter
d. uniporter 16. The molecule shown above belongs to which class of lipids?
d. fatty acid
17. Transport proteins that couple the movement of one ion or molecule against its concentration
gradient with movement of another molecule or ion down its concentration gradient are called:
d. a and b
e. b and c
18. The diffusion of gases across membranes occurs by facilitated diffusion.
19. Use of energy to power the movement of molecules against their electrical gradient requires
which type of transporter?
c. ATP-powered pumps
d. antiporter 3 20. An enzyme can catalyze a reaction with two different substrates. The Km for the reaction
with the substrate having higher affinity for the enzyme is
a. the same as that of the substrate with lower affinity
b. higher than that of the reaction with the lower affinity substrate
c. lower than that of the reaction with the lower affinity substrate
21. The allosteric molecule that regulates the function of protein kinase A is
22. Which lipid is more abundant in the inner leaflet of the plasma membrane than in the outer
23. The most common motif of the transmembrane domain of an integral membrane protein is
a. alpha helix
b. beta sheet
24. A transporter protein displays much higher affinity towards glucose than galactose. We
should expect that:
a. The Km for glucose will be much smaller than for galactose
b. The Km for glucose will be much higher than for galactose
25. Sphingolipids are derived from
26. Is cholesterol amphipathic?
27. Phosphoglycerides are derived from
a. glyceraldehyde 3-phosphate
b. glycerol 3-phosphate
d. gyceraldehyde 4-phosphate 4 28. Mechanisms for moving molecules against their concentration gradient include all of the
b. ATP pump
29. Increasing the enzyme concentration and leaving the substrate concentration constant will
increase the Km of the reaction?
30. Which type of fatty acyl chains contribute to a membrane having a more fluid-like state?
31. Phosphoglycerides are synthesized on what leaflet of which organelle?
a. exoplasmic – Golgi
b. cytosolic- Golgi
c. exoplasmic – ER
d. cytosolic – ER
32. In bacteria, all proteins are synthesized on the endoplasmic reticulum
33. The most abundant lipids in bimembranes are
34. The most common phosphoglyceride in membranes is
35. The macromolecular assembly of proteins that uses ATP for energy to facilitate the folding
of proteins is
a. molecular chaperone
d. chaperonin 5 36. The chemical modification found on the amino terminus of about 80% of all proteins that
regulates their stability or life span is
37. In an alpha-helix the carbonyl oxygen atom of one amino acid forms a hydrogen bond with
the amide hydrogen atom of the amino acid how many residues toward the C-terminus?
38. In an alpha-helix, the side chains of the amino acids are oriented how?
a. all face the inside
b. all face the outside
c. alternate inside and outside every other amino acid
d. three amino acids have side chains inside and the fourth is outside
39. Tertiary structure is generated by covalent interactions between different regions of a protein.
40. The DNA of bacteria is a single circular double helix.
41. For an organelle or vesicle with a single lipid bilayer, the exoplasmic face is
a. directed toward the cytosol
b. directed toward the lumen
42. The change in a protein’s tertiary and/or quaternary structure induced by the binding of a
ligand is called:
a. secondary structure
d. primary structure
43. If a cell is placed in a hypotonic solution, it will
a. remain the same size
c. swell 6 44. In the transport system above, which is the energetically favorable movement?
45. Which has the higher concentration on the exterior of the membrane when compared to the
46. Osmosis is the movement of water across lipid bilayers from a region of high solute
concentration to low solute concentration.
47. Multipass membrane spanning proteins such as the G protein coupled receptors and have as
a structural feature
a. seven membrane spanning alpha-helices
b. five membrane spanning alpha-helices
c. seven membrane spanning beta sheets
d. five membrane spanning beta sheets
48. Lipid-anchored proteins are only found on the cytosolic side of the plasma membrane.
49. Prenylation is the covalent attachment of a farnesyl or geranygeranyl lipid to which amino
acid on which terminus of the protein?
a. glycine – amino terminus
b. cysteine – amino terminus
c. glycerol – carboxy terminus
d. cysteine – carboxy terminus 7 50. The transporter shown below is an example of
a. a symporter
b. a P class ATP-powered pump
c. a V class ATP-powered pump
d. a antiporter 8 ...
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- Spring '11
- Biology, A., class ATP pump