Exam4_2012_B

The following constituents of lipoprotein particles

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: is or β- oxidation. For each statement, list the metabolic pathway it describes. (i) Intermediate is attached to acyl carrier protein (ACP). Answer: ________________ (FA synthesis or β- oxidation) (ii) Takes place in mitochondria matrix. Answer: ________________ (FA synthesis or β- oxidation) (iii) Flux into the pathway is decreased upon inhibition of carnitine acyltransferase I (carnitine palmitoyltransferase I, CPT- I) by malonyl- CoA. Answer: ________________ (FA synthesis or β- oxidation) Question 8. (6 pts) Glutathione is the major anti- oxidant in cells. Glutathione reductase re- generates reduced glutathione from oxidized glutathione. Many individuals of African descent are heterozygous for inactivating mutations in the gene encoding glucose 6- phosphate dehydrogenase because oxidative stress, while harmful to cells, is also harmful to Plasmodium and thus protects against malaria. Glucose 6- phosphate dehydrogenase catalyzes oxidation of glucose 6- phosphate to phosphogluconolactone in the pentose phosphate pathway. (A) (3 pts) Discuss why fatty acid synthesis could potentially be decreased in individuals with such mutation. Page 3 of 3 Name: _______________________________________ Net ID: ______________________ (B) (3 pt) Any of the following could potentially normalize fatty acid synthesis in individuals with inactivating mutation in glucose 6- phosphate dehydrogenase. Pick one of the events and describe how it may normalize fatty acid synthesis. (A) (B) (C) (D) Increased malic enzyme levels in cytosol leading to increased conversion of malate to pyruvate Decreased levels of malate–α- ketoglutarate transporter on inner mitochondrial membrane Increased levels of pyruvate transporter on inner mitochondrial membrane Hyper- activation of pyruvate carboxylase by acetyl- CoA Question 9. (10 pts) A serine to alanine mutation is identified in acetyl- CoA carboxylase (ACC) on the site that is normally phosphorylated by protein kinase A (PKA). As a result, this mutant ACC cannot respond to PKA following glucagon or epinephrine stimulation. (A) (2 pts) Identify the product of ACC. Answer: _______________________ (B) (2 pts) Identify the effect of glucagon or epinephrine on fatty acid synthesis in individual with normal (wild- type) ACC as inc...
View Full Document

This note was uploaded on 09/19/2013 for the course BIOC 462b taught by Professor Grimes,tsao,borque during the Spring '08 term at Arizona.

Ask a homework question - tutors are online