Which of the following must exist in a population before natural selection can act upon that population?

#Question id: 1005

#Unit 1. Molecules and their Interaction Relevant to Biology

The first step in the de novo biosynthesis of IMP is a reaction between glutamine and PRPP. Which statement is not true about this reaction?

#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.