Following statements are regarding to recognition of sperm by mammalian zona pellucida.

A. Sperm that have undergone the acrosome reaction bind directly to zona protein ZP2 and begin making a channel toward the oocyte.

B. Sperm with an intact acrosome bind to ZP2; they undergo the acrosome reaction on the zona pellucida and then transfer their binding to ZP3.

C. When a sperm reaches the oocyte and fuses with it, the cortical granules release proteins that digest portions of ZP2 and ZP3, making them nonfunctional and prevent polyspermy.

D. When a sperm reaches the oocyte and fuses with it, the cortical granules release proteins that digest ZP3 only, not ZP2 because ZP2 involve in the process of slow block to polyspermy.

Which of the above statements are correct?

#Question id: 1004

#Unit 1. Molecules and their Interaction Relevant to Biology

Which structure below is PRPP?

#Question id: 1003

#Unit 1. Molecules and their Interaction Relevant to Biology

The glucose-alanine cycle provides ________.

#Question id: 1002

#Unit 1. Molecules and their Interaction Relevant to Biology

What would be the product of the transamination of the structure shown below? (The unionized forms are shown.)

#Question id: 1001

#Unit 1. Molecules and their Interaction Relevant to Biology

The following fatty acid, in which the indicated carbon is labeled with ¹⁴C, is fed to an animal:  ¹⁴CH₃(CH₂)₉COOH After allowing 30 minutes for fatty acid B oxidation, the label would most likely be recovered in:

#Question id: 1000

#Unit 1. Molecules and their Interaction Relevant to Biology

 Which of the following is (are) true of the B oxidation of long-chain fatty acids?

1. The enzyme complex that catalyzes the reaction contains biotin.

2. FADH2 serves as an electron carrier.

3. NADH serves as an electron carrier.

4. Oxidation of an 18-carbon fatty acid produces six molecules of propionyl-CoA.

5. Oxidation of a 15-carbon fatty acid produces at least one propionyl-CoA.

#Question id: 999

#Unit 1. Molecules and their Interaction Relevant to Biology

The balanced equation for the degradation of CH3(CH2)10COOH via the B-oxidation pathway is: