Exam I blue key 2011

Exam I blue key 2011 - Exam I Blue BIOL 3030 Cell Biology...

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Unformatted text preview: Exam I Blue BIOL 3030 Cell Biology 1. 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 2. 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 d. ribosomes 3. The membrane-bound organelle that is involved in degradation of proteins taken up by the cell is a. peroxisome b. lysosome c. endocytic vesicle d. Golgi e. endoplasmic reticulum 4. Lysosomes are involved in degrading cellular structures such as old organelles. The name for this process is a. phagocytosis b. pinocytosis c. apoptosis d. autophagy 5. The macromolecular machine that recognizes ubiquitinated proteins and degrades them into 7-8 amino acid peptide is called a. chaperonin b. transcriptome c. signalasome d. proteasome 6. 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 1 7. Multidrug resistance protein (MDR1) belongs to what class of transporter? a. symporter b. V class ATP pump c. ABC transporter d. uniporter 8. The molecule shown above belongs to which class of lipids? a. phospholipids b. cholesterol c. spingolipid d. fatty acid 9. 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. 10. 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 gradients. 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. 11. The class of ATP-powered transporters that moves lipid molecules from one leaflet to the other is a. P class b. V class c. F class d. ABC 12. Potassium can cross cell membranes by passive diffusion. a. true b. false 2 13. 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: a. uniporters b. antiporters c. symporters d. a and b e. b and c 14. The diffusion of gases across membranes occurs by facilitated diffusion. a. true b. false 15. Use of energy to power the movement of molecules against their electrical gradient requires which type of transporter? a. uniporter b. symporter c. ATP-powered pumps d. antiporter 16. Which lipid is more abundant in the inner leaflet of the plasma membrane than in the outer leaflet? a. cholesterol b. sphingomyelin c. phosphatidylcholine d. phosphatidylserine 17. The most common motif of the transmembrane domain of an integral membrane protein is a. alpha helix b. beta sheet 18. 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 19. Sphingolipids are derived from a. sphingomyelin b. sphingocholine c. sphingosine d. sphingoethanolamine 20. Is cholesterol amphipathic? a. yes b. no 3 21. Which type of fatty acyl chains contribute to a membrane having a more fluid-like state? a. saturated b. unsaturated 22. Phosphoglycerides are synthesized on what leaflet of which organelle? a. exoplasmic – Golgi b. cytosolic- Golgi c. exoplasmic – ER d. cytosolic – ER 23. In bacteria, all proteins are synthesized on the endoplasmic reticulum a. true b. false 24. The most abundant lipids in bimembranes are a. triglycerides b. cholesterol c. phosphoglycerides d. sphingolipids 25. The most common phosphoglyceride in membranes is a. phosphodidylcholine b. phosphodidylserine c. phosphotidylethanolamine d. phosphotidylinositol 26. Phosphoglycerides are derived from a. glyceraldehyde 3-phosphate b. glycerol 3-phosphate c. glycolipid d. gyceraldehyde 4-phosphate 27. Mechanisms for moving molecules against their concentration gradient include all of the following except: a. uniporter b. ATP pump c. symporter d. antiporter 28. Increasing the enzyme concentration and leaving the substrate concentration constant will increase the Km of the reaction? a. true b. false 4 29. 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 30. The allosteric molecule that regulates the function of protein kinase A is a. ATP b. GTP c. cAMP d. cGMP 31. The macromolecular assembly of proteins that uses ATP for energy to facilitate the folding of proteins is a. molecular chaperone b. proteasome c. proteome d. chaperonin 32. The chemical modification found on the amino terminus of about 80% of all proteins that regulates their stability or life span is a. phosphorylation b. acetylation c. glycosylation d. methylation 33. 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? a. 3 b. 4 c. 5 d. 6 34. 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 35. Tertiary structure is generated by covalent interactions between different regions of a protein. a. true b. false 5 36. The DNA of bacteria is a single circular double helix. a. true b. false 37. For an organelle or vesicle with a single lipid bilayer, the exoplasmic face is a. directed toward the cytosol b. directed toward the lumen 38. The change in a protein’s tertiary and/or quaternary structure induced by the binding of a ligand is called: a. secondary structure b. allostery c. anergy d. primary structure 39. If a cell is placed in a hypotonic solution, it will a. remain the same size b. shrink c. swell 40. In the transport system above, which is the energetically favorable movement? a. glucose b. sodium 41. Which has the higher concentration on the exterior of the membrane when compared to the interior? a. glucose b. sodium 42. Osmosis is the movement of water across lipid bilayers from a region of high solute concentration to low solute concentration. a. true b. false 6 43. 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 44. Lipid-anchored proteins are only found on the cytosolic side of the plasma membrane. a. true b. false 45. 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 46. 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 7 47. Glycosylation involves the addition of carbohydrates to which region of a protein a. transmembrane b. exoplasmic c. cytosolic 48. Organelles with two lipid bilayers include all of the following, except: a. nucleus b. peroxisome c. chloroplast d. mitochondria 49. Endosomes deliver extracellular material to which degradative vesicle? a. lysosome b. peroxisome c. autophagosome d. COPI vesicle 50. The class of pumps that maintain acidic pH within organelles such as the lysosome is a. uniporter b. P class ATP pump c. V class ATP pump d. F class ATP pump 8 ...
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This note was uploaded on 02/14/2011 for the course BIOL 3030 taught by Professor Deborahvestal during the Spring '11 term at Toledo.

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