Review - Metabolism
Glycolysis is the process that takes
glucose to pyruvate and then to acetyl CoA.
In ten more reactions (the Krebs
Cycle), acetyl CoA is taken to carbon
dioxide.
1. Examine the ten reactions of the Krebs Cycle and characterize each
reaction in terms of the following aspects:
a) Write a balanced reaction and describe the reaction with as much specificity
as you can (e.g., oxidation of a secondary alcohol to a ketone).
b) Indicate whenever a cofactor is needed to accomplish an oxidation or
a reduction. Use NADH/NAD+ to interconvert alcohols and carbonyl groups and
use FADH2/FAD for hydrocarbons and alkenes.
c) Indicate any stereochemistry possibilities in the reactants or products.
2. Consider the ten reactions of the Krebs Cycle all together in
terms of the following aspects:
a) Write a balanced reaction for the entire cycle, in particular adding
up the cofactors that are used and generated.
b) Using other reaction sequences, each equivalent of NADH ultimately can
create 3 equivalents of ATP and each equivalent of FADH2 can
ultimately create 2 equivalents of ATP.
How much ATP can be created from one acetyl CoA? How many from one glucose?
The Krebs Cycle
Materials adapted from:
Peer-Led Team Learning: Organic Chemistry, 1/e
Jack A. Kampmeier, University of Rochester
Pratibha Varma-Nelson, St. Xavier University
Donald Wedegaertner, University of the Pacific
Prentice-Hall, 2001, ISBN 0-13-028413-0
http://www.sci.ccny.cuny.edu/~chemwksp/OrganicChem.html
