厦门大学生物化学考试试卷

Ⅰ. Fill in the blanks with only one choice. (1 score per question, 30 scores in total )

1. The most abundant RNA in cells is .

A. mRNA

B. tRNA

C. rRNA

D. hnRNA

2. Which of the following descriptions is not indicated by the Watson and Crick’s Double Helix model.

A. DNA is a complementary double helix.

B. Two strands are held together by hydrogen bonds formed between unique base pairs.

C. The base pairs are adenine with thymine, and guanine with cytosine.

D. The double helix is left-handed.

3. Double stranded DNA molecules assume one of three secondary structures,

termed .

A. T, C and Z

B. A, B and Z

C. C, D and B

D. A, B and P

4. Denaturation of DNA can not be caused by .

A. Strong H-bonding solutes such urea.

B. Increase of temperature

C. Increase of sodium chloride concentration.

D. pH extremes

5. Suppose DNA gyrase puts five negative supercoils into 500-bp right-handed circular relaxed duplex DNA. Then the numbers of L, T and W are , individually.

A. 45, 50 and -5

B. 50, 0 and 50

C. 50, 50 and 0

D. 50, 45 and -5

6. Organisms are classified into four groups as follows, all animals belong to .

A. photoautotrophs

B. Chemoheterotrophs

C. photoheterotrophs

D. Chemoautotrophs

7. Which of following biomolecules is not an amphibolic intermediate.

A. Pyruvate

B. Glucose-6-P

C. Fumarate

D. Glycogen

8. Which of following coenzymes acts exclusively as two-electron carrier.

A. NAD+

B. FMN

C. FAD

D. CoQ

9. that acts in TCA cycle, is also a component of complex II of the electron transport chain.

A. Citrate synthase

B. Aconitase

C. Succinate dehydrogenase

D. Fumarase

10. Which of following descriptions about regulation of pyruvate dehydrogenase is wrong.

A.A cetyl-CoA allosterically inhibits this enzyme.

B.N ADH allosterically inhibits this enzyme.

C.A TP allosterically inhibits this enzyme.

D.T his enzyme is not regulated by phosphorylation.

11. The correct sequence of electron transfer on electron transport chain is .

A. ComplexⅠComplexⅡComplexⅢComplexⅣ

B. ComplexⅡComplexⅢCyt a3Cyt c ComplexⅣ

C. NADH CoQ Cyto c CuA CuB

D. NADH CoQ Cyto c CuB CuA

12. The numbers of protons pumped by complexⅠ, Ⅱ, Ⅲ and Ⅳ from mitochondria matrix

to the cytosol are , separately.

A. 4, 2, 0 and 2

B. 4, 0, 4 and 2

C. 2, 4, 2 and 4

D. 4, 2, 4 and 0

13. The shuttle systems that feed the electrons of cytosolic NADH into electron transport

are .

A. citrate-malate-pyruvate shuttle and glycerophosphate shuttle.

B. malate-aspartate shuttle and glycerophosphate shuttle.

C. malate-aspartate shuttle and citrate-malate-pyruvate shuttle.

D. malate-oxiloacetate shuttle and glycerophosphate shuttle.

14. Complete oxidation of one molecule of stearic acid (18-carbon saturated, unbranched fatty

acid) to CO2 and H2O can yield molecules of ATP.