451 http://www4.ncsu.edu/~knopp/BCH451/e04b4.htm
BCH Summer 2004 1.
Exam #4
NAME
Draw the predominate structures of the following molecules at the pH indicated. Be sure to include all carbon and hydrogen atoms! a. b. (1) cAMP @ pH = 7.5 (1) L-histidine @ pH = 5.5
2.
(4) For step 6 of glycolysis, name the enzyme, give the class of the enzyme, draw the structures of the non-cofactor substrate(s) and product(s) connected by the reaction arrow(s), show reversibility or irreversibility by the directions of the arrow(s), show co-substrates coming in and out of the reaction as appropriate with the usual abbreviations, and list all other cofactors under the reaction arrow. Enzyme class:
Enzyme name: Reaction: 3.
(4) For step 4 of the TCA cycle, name the enzyme, give the class of the enzyme, draw the structures of the non-cofactor substrate(s) and product(s) connected by the reaction arrow(s), show reversibility or irreversibility by the directions of the arrow(s), show co-substrates coming in and out of the reaction as appropriate with the usual abbreviations, and list all other cofactors under the reaction arrow. Enzyme class:
Enzyme name: Reaction: 4.
For complex IV in oxidative phosphorylation, using full names and not abbreviations:
(0.3) full and complete name: (0.2) number of protons which enter the complex from matrix: (0.2) number of protons pumped out of complex into the inner membrane space: (0.4) substrates / cosubstrates [no structures]: (0.4) products / "co-products" [no (0.6) structures]: cofactors/prosthetic group(s) [do not list cosubstrates here]: (1) draw a well-labeled sketch of this complex, showing all substrates, products and cofactors 5. (0.3 each) List the enzymes which are unique to glycolysis and list the enzymes which replace them in gluconeogensis: In the appropriate boxes, give the regulators and indicate with + or - whether they are positive or negative regulators
glycolysis enzyme
gluconeogenesis enzyme
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http://www4.ncsu.edu/~knopp/BCH451/e04b4.htm
6. 7. 8. 9. 10. 11. 12. 13.
(0.5) What is substrate level phosphorylation? (0.3 per term) Give the balance equation for the TCA cycle: (0.3 each) List the products of one turn of the oxidation cycle: (0.5 each) List the chemistry of each step in oxidation in order: (1) In the malate-aspartate shuttle, what is the role of glutamate? (1) Why is there no mitochondrial translocase for OAA? (1) What is the significance of glutamate dehydrogenase? (2) PUZZLER Why can two isozymes of pyruvate carboxylase be isolated from mammalian cells?
14. 15.
(0.3 each) List the enzyme(s) which is(are) unique to the glyoxylate shunt: (2.5) Give the pathway by which mannose enters glycolysis, listing all enzymes and drawing all non-coenzyme substrates and products: (5) Draw an appropriate sketch of the regulation of pyruvate dehydrogenase which ONLY OCCURS IN MAMMALS. Indicate all enzymes and regulators. For each regulator, indicate its source [pathway].
16.
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