5. In hemoglobin, the transition from T state to R state (low to high affinity) is triggered by:
(A) binding.
(B) heme binding.
(C) oxygen binding.
(D) subunit association.
(E) subunit dissociation. 

1. Please choose the correct answer from the following descriptions:  1. Every turn of a-helix is 10.4 A in length.  2. The side-chain of Histidine is an indole group and has important role in maintaining pH in blood. 3. Frederick Sanger developed a method for DNA scquencing and won Nobel prize. 4. Dextrin is homopolysaccharide.  5. Trehalose is the inajor constituent in circulating fluid of insects as energy-storage compound. (A) Only 2 and 5 are incorrect. (B) 3, 4, and 5 are cotrect. (C) 2 and 5 are correct. (D) All descriptions are incorrect. (E) Only 1 and 4 are incorrect.

2. Please choose the correct answer from the following descriptions: 1. Dextran is homopolysaccharide and the material for beads in gel filtration. 2. Agarose is the material for making SDS gel. 3. Heparin is sulfated hetereopolysaccharide.  4. The strength of a-keratin depends on its Cys content. 5. Hydrogen bond in a-helix formed between residue i and i+4. (A) I and 3 are incorrect. (B) 2 and 5 are incorrect.(C)2 and 5 are correct (D) Only 2 is incorrect. (E) Only 3, 4, and 5 are correct.

3. Please choose the correct answer(s) from the following desctiptions:  1. Lectin are proteins that bind carbohydrate with high specificity.  2. The antiviral drug Tamiflu block the infection cycle of virus by inhibiting viral sialidase. 3. An oligosaccharise containing sialic acid marks newly synthesized protein in Golgi for transfer to lysosome.  4. The synthesis sequence in solid state peptide synthesis is from N-terminal to C-terminal. 5. Eukaryotes are more close to eubacteria than to archacobacteria in evolution. (A) 2, 3, and 5 are incorrect. (B) 2, 3, and 4 are correct. (C) 1 and 2 are correct. (D) Only 3 is incorrect. (E) 1 and 5 are correct.

4. If the of the reaction A →B is -40 kJ/mol, under standard conditions the reaction: (A) is at equilibrium. (B) will never reach equilibrium. (C) will not occur spontan neously. (D) will proceed spontancously from left to right. (E) will proceed spontancously from right to left.

6. Which one of the following statements about Pentosc Phosphate Pathway (PPP) is false?  1. The enzyne transaidolase is used twice and the enzyme transketolase is used once in PPP. 2. The enzyme phosphopentose isomerase is characterized by it converts an aldose to a ketose.  3. Two-carbon shift reactions is catalyzed by transketolase. 4. NADPH and xylulose-S-phosphate are products in the oxidative reaction. 5. Glucose-6-phosphate will be channeled into the PPP if NADPH is needed. (A) 1, 2, and 3 are false. (B) 1, 4, and 5 are false. (C) 1 and 2 are false. (D) 2, 3, and 4 are false. (E) None is false.

7. Which one is an ω-6 fatty acid? (A)(B)(C) (D)(E)

8. Which one is the basic unit for lipid synthesis? (A)Malonyl Co-A (B) Choline (C)Phosphatic acid(D) Glycerophospholipid (E) Squalene

9. Which one regarding the compartmentalization of lipid metabolism is incorrect? (A) Fatty acid oxidation occurs in the mitochondria. (B) Ketone body synthesis takes place in the mitochondria. (C) Late stages of sterol synthesis take place in the ER. (D) Fatty acid synthesis occurs in the cytosol. (E) Acetyl-CoA is produced in the cytosol.

10. Which one is a secondary active transporter? (B) SERCA punp (A) GLUTI (C) Acetylcholine receptor (D) Lactose H+transporter (E) Caveolin

11. Which one is involved in HDL-mediated reverse cholesterol transport to the liver? (A)ABCA I(B) Acyl-CoA cholesterol acyl transferase (ACAT) (C) Sterol regulatory element-binding proteins (D) HMG-CoA reductase (E) Acetyl-CoA Carboxylasc