100cps2s09

# 100cps2s09 - Biochemistry Molecular Biology 100C Problem...

This preview shows pages 1–2. Sign up to view the full content.

Biochemistry & Molecular Biology 100C Problem Set #2 due: April 20, 2009. 1. The enzyme acyl-CoA synthetase, which activates aliphatic, long-chain fatty acids for catabolism, involves ATPαβ hydrolysis (–10.0 kcal/mole under bioenergetic standard conditions). Using additional information provided in lecture and/or text, and given the overall equation for the reaction: RCOO + ATP + CoA-SH ↔ RCO~S-CoA + 5´-AMP + PP i ΔG°´= –2.5 kcal/mole where PP i is the abbreviation for pyrophosphate, P 2 O 7 3– , and CoA-SH that for coenzyme-A, which contains an active sulfhydryl group, (a) Calculate ΔG°´(hydrolysis) for the acyl-thioester product: RCO~S-CoA + H 2 O RCOO + CoA-SH (b) In the “Phospho-Group Transfer Potential” table, an aliphatic acyl-adenylate is listed as ΔG°´= –10.5 kcal/mole. For liver tissue rapidly catabolyzing long-chain fatty acids, ATP is present at 15 m M and RCOO is present at 8 m M steady-state. What minimum steady-state PP i concentration allows formation of the acyl-adenylate intermediate? (c) Conceptually, under what steady-state intracellular conditions are fatty acids "mobilized" for rapid catabolism as cell energy source? (d) Calculate ΔG´ for the formation of the acyl-adenylate intermediate if PP i is actually maintained at 0.1 m M steady-state. (e) Calculate ΔG°´ for the second step in the reaction:

This preview has intentionally blurred sections. Sign up to view the full version.

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

## This note was uploaded on 03/16/2010 for the course BIOC 100A taught by Professor Harrynoller during the Winter '10 term at UCSC.

### Page1 / 3

100cps2s09 - Biochemistry Molecular Biology 100C Problem...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online