Exam I green key 2011

Exam I green key 2011 - Exam I Green BIOL 3030 Cell Biology...

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Unformatted text preview: Exam I Green BIOL 3030 Cell Biology 1. Glycosylation involves the addition of carbohydrates to which region of a protein a. transmembrane b. exoplasmic c. cytosolic 2. Organelles with two lipid bilayers include all of the following, except: a. nucleus b. peroxisome c. chloroplast d. mitochondria 3. Endosomes deliver extracellular material to which degradative vesicle? a. lysosome b. peroxisome c. autophagosome d. COPI vesicle 4. 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 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 d. ribosomes 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 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. 9. 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 10. Potassium can cross cell membranes by passive diffusion. a. true b. false 11. 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 12. 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 13. 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 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? a. symporter b. V class ATP pump c. ABC transporter d. uniporter 16. The molecule shown above belongs to which class of lipids? a. phospholipids b. cholesterol c. spingolipid 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: a. uniporters b. antiporters c. symporters d. a and b e. b and c 18. The diffusion of gases across membranes occurs by facilitated diffusion. a. true b. false 19. 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 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 a. ATP b. GTP c. cAMP d. cGMP 22. 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 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 a. sphingomyelin b. sphingocholine c. sphingosine d. sphingoethanolamine 26. Is cholesterol amphipathic? a. yes b. no 27. Phosphoglycerides are derived from a. glyceraldehyde 3-phosphate b. glycerol 3-phosphate c. glycolipid d. gyceraldehyde 4-phosphate 4 28. Mechanisms for moving molecules against their concentration gradient include all of the following except: a. uniporter b. ATP pump c. symporter d. antiporter 29. Increasing the enzyme concentration and leaving the substrate concentration constant will increase the Km of the reaction? a. true b. false 30. Which type of fatty acyl chains contribute to a membrane having a more fluid-like state? a. saturated b. unsaturated 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 a. true b. false 33. The most abundant lipids in bimembranes are a. triglycerides b. cholesterol c. phosphoglycerides d. sphingolipids 34. The most common phosphoglyceride in membranes is a. phosphodidylcholine b. phosphodidylserine c. phosphotidylethanolamine d. phosphotidylinositol 35. 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 5 36. 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 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? a. 3 b. 4 c. 5 d. 6 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. a. true b. false 40. The DNA of bacteria is a single circular double helix. a. true b. false 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 b. allostery c. anergy d. primary structure 43. If a cell is placed in a hypotonic solution, it will a. remain the same size b. shrink c. swell 6 44. In the transport system above, which is the energetically favorable movement? a. glucose b. sodium 45. Which has the higher concentration on the exterior of the membrane when compared to the interior? a. glucose b. sodium 46. Osmosis is the movement of water across lipid bilayers from a region of high solute concentration to low solute concentration. a. true b. false 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. a. true b. false 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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