Following statements are regarding to maternally provided mRNAs—hunchback and caudal, are critical for patterning the anterior and posterior regions of the body plan, respectively.

A. These two mRNAs are synthesized by the nurse cells of the ovary and transported to the oocyte, where they are distributed ubiquitously throughout the syncytial blastoderm.

B. Translation of the hunchback and caudal mRNAs is repressed by the diffusion gradients of Bicoid and Nanos proteins, respectively.

C. Bicoid binds to a specific region of caudal’s 3′UTR. Here, it binds Bin3, a protein that stabilizes an inhibitory complex that prevents the binding of the mRNA 5′ cap to the ribosome. By recruiting this translational inhibitor, Bicoid prevents translation of caudal in the anterior of the embryo.

D. Nanos protein prevents translation of the hunchback message. Nanos in the posterior of the embryo forms a complex with several other ubiquitous proteins, including Pumilio and Brat. This complex binds to the 3′UTR of the hunchback message, where it recruits d4EHP and prevents the hunchback message from attaching to ribosomes.

Which of the following statements are true?

#Question id: 993

#Unit 1. Molecules and their Interaction Relevant to Biology

What is the correct order of function of the following enzymes of beta oxidation?

1. B-Hydroxyacyl-CoA dehydrogenase

2. Thiolase

3. Enoyl-CoA hydratase

4. Acyl-CoA dehydrogenase

#Question id: 994

#Unit 1. Molecules and their Interaction Relevant to Biology

If the 16-carbon saturated fatty acid palmitate is oxidized completely to carbon dioxide and water (via the B-oxidation pathway and the citric acid cycle), and all of the energy-conserving products are used to drive ATP synthesis in the mitochondrion, the net yield of ATP per molecule of palmitate is:

#Question id: 995

#Unit 1. Molecules and their Interaction Relevant to Biology

Saturated fatty acids are degraded by the stepwise  reactions of B oxidation, producing acetyl-CoA. Under aerobic conditions, how many ATP molecules would be produced as a consequence of removal of each acetyl-CoA?

#Question id: 996

#Unit 1. Molecules and their Interaction Relevant to Biology

Which of the following is (are) true of the oxidation of 1 mol of palmitate (a 16-carbon saturated fatty acid; 16:0) by the B-oxidation pathway, beginning with the free fatty acid in the cytoplasm?

1. Activation of the free fatty acid requires the equivalent of two ATPs.

2. Inorganic pyrophosphate (PPi) is produced.

3. Carnitine functions as an electron acceptor.

4. 8 mol of FADH2 are formed.

5. 8 mol of acetyl-CoA are formed.

6. There is no direct involvement of NAD+.

#Question id: 997

#Unit 1. Molecules and their Interaction Relevant to Biology

Complete oxidation of 1 mole of which fatty acid would yield the most ATP?

#Question id: 998

#Unit 1. Molecules and their Interaction Relevant to Biology

Which of the following statements apply (applies) to the B oxidation of fatty acids?

1.  The process takes place in the cytosol of mammalian cells.

2.  Carbon atoms are removed from the acyl chain one at a time.

3.  Before oxidation, fatty acids must be converted to their CoA derivatives.

4.  NADP+ is the electron acceptor.

5.  The products of B oxidation can directly enter the citric acid cycle for further oxidation.