大学MOOC Biochemistry(China Medical University)1461612163 最新慕课完整章节测试答案

quiz1

1、单选题：
‎Which one below is NOT a kind of high energy compound?‌
选项：
A: ATP
B: G-6-P
C: Glycerate-1,3-bisphosphate
D: Phosphocreatine
答案: 【 G-6-P】

2、单选题：
‏Enzymes are potent catalysts because they:‎
选项：
A: are consumed in the reactions they catalyze.
B: are very specific and can prevent the conversion of products back to substrates.
C: increase the equilibrium constants for the reactions they catalyze.
D: lower the activation energy for the reactions they catalyze.
答案: 【 lower the activation energy for the reactions they catalyze.】

3、单选题：
​Which statement about allosteric control of enzymatic activity is FALSE?‌
选项：
A: Allosteric effectors give rise to sigmoidal V versus [S] kinetic plots.
B: An effector may either inhibit or activate an enzyme.
C: Binding of the effector changes the conformation of the enzyme molecule.
D: Heterotropic allosteric effectors compete with substrate for binding sites.
答案: 【 Heterotropic allosteric effectors compete with substrate for binding sites.】

4、单选题：
​A small molecule that DECREASES the activity of an enzyme by binding to a site other than the catalytic site is termed a(n):​
选项：
A: allosteric inhibitor.
B: alternative inhibitor.
C: competitive inhibitor.
D: stereospecific agent.
答案: 【 allosteric inhibitor.】

5、单选题：
‏Which amino acid is NOT one that may be targeted for phosphorylation to modulate the activity of an enzyme?‌
选项：
A: Tyr
B: Ser
C: Ala
D: Thr
答案: 【 Ala】

6、单选题：
​Which type of enzyme is responsible for attaching phosphate groups to specific amino acids?‎
选项：
A: a protein phosphatase
B: a protein kinase
C: a protein glycosylase
D: an ATPase
答案: 【 a protein kinase】

quiz2

1、单选题：
‌Which reaction in glycolysis requires ATP as a substrate?‏
选项：
A: hexokinase
B: glyceraldehyde-3-phosphate dehydrogenase
C: pyruvate kinase
D: aldolase
答案: 【 hexokinase】

2、单选题：
‌Which reaction in glycolysis produces ATP as a product?‎
选项：
A: hexokinase
B: glyceraldehyde-3-phosphate dehydrogenase
C: pyruvate kinase
D: phosphofructokinase-1
答案: 【 pyruvate kinase】

3、单选题：
‌During strenuous exercise, the NADH formed in the glyceraldehyde 3-phosphate dehydrogenase reaction in skeletal muscle must be reoxidized to NAD+ if glycolysis is to continue.  The most important reaction involved in the reoxidation of NADH is:‏
选项：
A: dihydroxyacetone phosphate → glycerol 3-phosphate.
B: pyruvate → lactate.
C:  isocitrate → α-ketoglutarate.
D: oxaloacetate → malate.
答案: 【 pyruvate → lactate.】

4、单选题：
‌The anaerobic conversion of 1 mol of glucose to 2 mol of lactate by fermentation is accompanied by a net gain of:‌
选项：
A:  1 mol of ATP.
B: 1 mol of NADH.
C:  2 mol of ATP.
D: 2 mol of NADH.
答案: 【  2 mol of ATP.】

5、单选题：
‌In comparison with the resting state, actively contracting human muscle tissue has a:‏
选项：
A:  higher concentration of ATP.
B: higher rate of lactate formation.
C: lower consumption of glucose.
D: lower rate of consumption of oxygen
答案: 【 higher rate of lactate formation.】

6、单选题：
‍Which compound CANNOT serve as the starting material for the synthesis of glucose via gluconeogenesis?‏
选项：
A: acetate
B: glycerol
C: lactate
D: oxaloacetate
答案: 【 acetate】

7、单选题：
‌An enzyme used in both glycolysis and gluconeogenesis is:‍
选项：
A: 3-phosphoglycerate kinase.
B: glucose 6-phosphatase.
C: hexokinase.
D: phosphofructokinase-1.
答案: 【 3-phosphoglycerate kinase.】

8、单选题：
‌Which statement about gluconeogenesis is FALSE?‌
选项：
A: For starting materials, it can use carbon skeletons derived from certain amino acids.
B: It consists entirely of the reactions of glycolysis, operating in the reverse direction.
C: It employs the enzyme glucose 6-phosphatase.
D: It is one of the ways that mammals maintain normal blood glucose levels
答案: 【 It consists entirely of the reactions of glycolysis, operating in the reverse direction.】

9、单选题：
‍ In humans, gluconeogenesis:‌
选项：
A: can result in the conversion of protein into blood glucose.
B: helps to reduce blood glucose after a carbohydrate-rich meal.
C: is essential in the conversion of fatty acids to glucose.
D: requires the enzyme hexokinase.
答案: 【 can result in the conversion of protein into blood glucose.】

10、单选题：
‌Which statement about the pentose phosphate pathway is CORRECT?‌
选项：
A: It generates 36 mol of ATP per mole of glucose consumed.
B: It is a reductive pathway; it consumes NADH.
C:  It is present in plants, but not in animals.
D:  It provides precursors for the synthesis of nucleotides.
答案: 【  It provides precursors for the synthesis of nucleotides.】

11、单选题：
‏The metabolic function of the pentose phosphate pathway is to:​
选项：
A: act as a source of ADP biosynthesis.
B: generate NADPH and pentoses for the biosynthesis of fatty acids and nucleic acids.
C: participate in oxidation-reduction reactions during the formation of H2O.
D: provide intermediates for the citric acid cycle.
答案: 【 generate NADPH and pentoses for the biosynthesis of fatty acids and nucleic acids.】

12、单选题：
‍Which compound(s) is/are a high-energy intermediate(s) in glycolysis?‍
选项：
A: fructose 1,6-bisphosphate
B: NADH
C: 1,3-bisphosphoglycerate and phosphoenol pyruvate
D: fructose 1,6-bisphosphate, 1,3-bisphosphoglycerate, and phosphoenol pyruvate
答案: 【 1,3-bisphosphoglycerate and phosphoenol pyruvate】

13、单选题：
​Malonate is a competitive inhibitor of succinate dehydrogenase.  If malonate is added to a mitochondrial preparation that is oxidizing pyruvate as a substrate, which compound would you expect to decrease in concentration?‎
选项：
A: citrate
B: fumarate
C: isocitrate
D: pyruvate
答案: 【 fumarate】

14、单选题：
‍Which compound is NOT an intermediate of the citric acid cycle?‏
选项：
A: acetyl-CoA
B: citrate
C: oxaloacetate
D: succinyl-CoA
答案: 【 acetyl-CoA】

15、单选题：
‌ In mammals, what process does NOT occur during the citric acid cycle?‎
选项：
A: formation of α-ketoglutarate
B: generation of NADH and FADH2
C: metabolism of acetyl-CoA to carbon dioxide
D: net synthesis of oxaloacetate from acetyl-CoA
答案: 【 net synthesis of oxaloacetate from acetyl-CoA】

16、单选题：
‍Conversion of 1 mol of acetyl-CoA to 2 mol of CO2 and CoA via the citric acid cycle results in the net production of:‍
选项：
A: 1 mol of citrate.
B: 1 mol of FADH2.
C: 1 mol of NADH.
D: 1 mol of oxaloacetate.
答案: 【 1 mol of FADH2.】

17、单选题：
‍Which factor is NOT associated with the oxidation of substrates by the citric acid cycle?‎
选项：
A: CO2 production
B: FADH2
C: NADH
D: NADPH
答案: 【 NADPH】

18、单选题：
​Which enzymatic activity would be decreased by thiamine deficiency?​
选项：
A: α-ketoglutarate dehydrogenase complex
B:  isocitrate dehydrogenase
C: malate dehydrogenase
D: fumarase
答案: 【 α-ketoglutarate dehydrogenase complex】

19、单选题：
‍The reaction of the citric acid cycle that produces an ATP equivalent (in the form of GTP) by substrate level phosphorylation is the conversion of:‌
选项：
A: succinyl-CoA to succinate.
B: citrate to isocitrate.
C: fumarate to malate.
D: succinate to fumarate.
答案: 【 succinyl-CoA to succinate.】

20、单选题：
​Which cofactor is required for the conversion of succinate to fumarate in the citric acid cycle?‎
选项：
A: ATP
B: biotin
C: FAD
D: NAD+
答案: 【 FAD】

21、单选题：
‎Which process is NOT a metabolic fate for pyruvate in liver tissue?​
选项：
A: reduction to lactate
B: oxidative decarboxylation to acetyl-CoA
C:  phosphorylation to phosphoenolpyruvate
D: carboxylation to oxaloacetate
答案: 【  phosphorylation to phosphoenolpyruvate】

22、单选题：
​Covalent modification is one way the activity of specific enzymes can be regulated. Which enzyme is NOT regulated in this way?‌
选项：
A: phosphofructokinase-2
B: pyruvate dehydrogenase
C: phosphorylase kinase
D: All of these enzymes are regulated by covalent modification.
答案: 【 All of these enzymes are regulated by covalent modification.】

23、单选题：
​Which statement about mammalian glycogen synthase is NOT correct?‎
选项：
A: It is especially predominant in liver and muscle.
B: The donor molecule is a sugar nucleotide.
C: The phosphorylated form of this enzyme is active.
D: This enzyme adds the initial glucose unit to a tyrosine residue in glycogenin.
答案: 【