所屬科目:研究所、轉學考(插大)◆生物化學
1.The molecule is generated during glycolysis and contains a high-energy phosphoanhydride bond: (A)fructose-1,6-bisphosphate (B) 1,3-bisphosphoglycerate (C)glyceraldehyde-3-phosphate (D) phosphoenolpyruvate.
2.The enzyme is required for the formation of oxaloacetate from pyruvate: (A)pyruvate decarboxylase (B) phosphoenolpyruvate carboxykinase (C)pyruvate carboxylase (D) pyruvate kinase.
3.One of molecules is generated from glycogen by debranching enzyme during glycogenolysis: (A)glucose-1-phosphate (B) glucose-6-phosphate (C)glucose (D) glucose-1,6-bisphosphate.
4.The enzyme is required for the formation of NADH during the citric acid cycle: (A)lactate dehydrogenase (B) succinate dehydrogenase (C)pyruvate dehydrogenase (D) malate dehydrogenase.
5.The mobile electron carrier in the electron transport chain: (A)cytochrome a (B) cytochrome c (C)flavoprotein (D) O2.
2.Which one of the following statements is correct?(A)An increase in gluconeogenesis from amino acidsresults in a decrease in urea formation(B) All essential amino acids are glycogenic(C)Ornithine and citrulline are found in tissueproteins(D) Cysteine is an essential amino acid in individualsconsuming a diet devoid of methionine(E) In the presence of adequate dietary sources oftyrosine, phenylalanine is not an essential aminoacid.
3.In folic acid-dependent carriage of a one-carbon group: (A)the formation of the methyl group of thymineinvolves a direct transfer from methyl THF(B) the first entry of carbons into the THF pool is viamethylene THF(C)carbons are fixed at the oxidation level at whichthey enter the pool(D) the only acceptor for the methyl form ishomocysteine(E) carbons are always carried on nitrogen 10 of thepteridine ring.
4.Elongation of a C20 fatty acid to a C24 fatty acid willmost likely occur in which subcellular compartment?(A)Lysosome (B) Mitochondria(C)endoplasmic reticulum (D) cytosoplasm (cytosol)(E) Peroxisome.
5.Increased formation of ketone bodies during starvationis due to:(A)Decreased levels of circulating glucagon.(B) Decreased formation of acetyl-CoA in liver(C)Increased levels of free fatty acids in serum(D) Inhibition of β-oxidation of fatty acids in liver(E) A decreased activity of hormone-sensitive lipase inadipose tissue.
1.Membrane transporters that couple downhill flow of onespecies to the uphill flow of another species in theopposite direction are called(A)antiporters (B) symporters(C)exchangers (D) All of the above(E) None of the above.
2.The fluidity of the lipid side chains in the interior of abilayer is generally increased by:(A)a decrease in temperature(B) an increase in fatty acyl chain length(C)an increase in the number of double bonds in fattyacids(D) an increase in the percentage of phosphatidylethanolamine(E) the binding of water to the fatty acyl side chains.
3.Facilitated diffusion through a biological membrane is:(A)driven by a difference of solute concentration(B) driven by ATP (C)endergonic(D) generallyirreversible(E) not specific with respect to thesubstrate.
4.The fluidity of a lipid bilayer will be increased by:(A)decreasing the number of unsaturated fatty acids(B) decreasing the temperature(C)increasing the length of the alkyl chains(D) increasing the temperature(E) substituting 18:0 (stearic acid) in place of 18:2(linoleic acid).
5.A channel that opens in response to binding a particularmolecule is called a ________ channel.(A)passive diffusion (B) symport(C)ligand-gated (D) All of the above(E) None of the above.
1. How many catalytic trimers in ATCase?(3 points) (A)1 (B)2 (C)3(D)6.
2. How many regulatory dimmers in ATCase? (3 points)(A)1 (B)2 (C)3(D)6.
3. Which domain is bound with ATP or CTP modulatorsduring the regulation of ATCase activity? (3 points)(A)C (B)R(C)both.
4. ATCase is classified as (3points)(A)transferase (B)hydrolase(C)ligase(D)oxidoreductase.
5. What kinds of symmetry built in ATCase? (3 points)(A)C2 (B)C3 (C)C4(D)D4.
II. Short answer: 1.Please briefly describe the role of pentose phosphatepathway. (5 points)
(a) gluconeogenesis
(b) the pentose phosphate pathway
(c) the Krebs’ tricarboxylic acid cycle
(d) decarboxylation of aromatic amino acids
(e) one-carbon transfer from tetrahydrofolatederivatives.
IV. Why do untreated diabetics lose weight? (10 points)
VI. Please describe the difference in energy input requiredbetween the primary active transporter and secondaryactive transporter. (5 points)
VII. Please define “integral membrane proteins”. (5 points)
6. How the activity of ATCase regulated by modulatorsthrough the structural changing? (5 points)
7. What’s the biological significance of ATP moleculefunctions as an activator to enhance the activity ofATCase? (5 points)