Homework 3 - Metabolic Biochemistry Summer Session 2011...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
Metabolic Biochemistry KEY Summer Session 2011 Homework 3 (40 pts.) 1) (7 pts.) Use the diagram below to answer the following questions about the reaction mechanism for the pyruvate dehydrogenase complex. a. On hydroxyethyl-TPP, circle the part of the hydroxyl ethyl group that gets oxidized in the following step—be as accurate as you can. b. Which enzyme catalyzes the oxidation step in part (a) above? E 1 or E 2 or E 3 c. Draw the structure of the chemical group that is attached to lipoyllysine here. d. Is this form of lipoyllysine oxidized or reduced? reduced e. Write in both forms of the missing electron carrier in the box (not the structure). f. Is this form of lipoyllysine oxidized or reduced? Oxidized g. This kind substrate transfer through multiple enzyme subunits and their coenzymes is known as Substrate Channeling CH 3 C O NAD + NADH
Background image of page 1

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

View Full DocumentRight Arrow Icon
2) (6 pts.) A test electrode contains a solution of ubiquinone, with both the fully oxidized and fully reduced forms, at 1 M concentration each. A circuit is formed from this electrode using a KCl solution salt bridge with a standard hydrogen electrode (25°C, 1 ATM H 2 , 1 M H + ). When this circuit is complete, a current of electrons pass to the ubiquinone test cell at +0.045 volts. a. What is the standard reduction potential (E°’) of ubiquinone? 0.045 volts The description given above is the definition of reduction potential. The reduction potential of a compound is defined relative to the standard hydrogen electrode. b. Which has a higher standard reduction potential, ubiquinone or oxygen? Oxygen. 3) (7 pts.) Complex 1 of the electron transport chain catalyzes the transfer of a hydride ion (2e - + H + ) from NADH to an electron carrier coenzyme, which carries the electrons to the next complex of the chain. a. What is the name of the coenzyme that receives the hydride ion from complex 1?
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 03/27/2012 for the course BIBC BIBC 102 taught by Professor Price during the Summer '08 term at UCSD.

Page1 / 5

Homework 3 - Metabolic Biochemistry Summer Session 2011...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online