Lecture23 - BCH 227 FALL 2010 LECTURE 23: OXIDATIVE...

Info iconThis preview shows pages 1–6. Sign up to view the full content.

View Full Document Right Arrow Icon
1 Oxidative Phosphorylation BIOCHEM 227 FALL 2010 Lecture 23 Monday, October 25, 2010 TODAY • Revisiting a couple of steps in gluconeogenesis and the Krebs cycle • Oxidative phosphorylation – General principles –E lectron transport – The [H + ] gradient – ATP synthesis BCH 227 FALL 2010 LECTURE 23:
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 Gluconeogenesis – Bypass to PEP PEP has a higher energy than oxaloacetate—GTP energy needed CO 2 decarboxylation also provides energy Δ G for the reaction is ~0, meaning that no energy is wasted Krebs Cycle – Step 3 Oxidizes carbon Z from COH to C=O Releases CO 2 from Y carbon to give CH 2 BCH 227 FALL 2010 LECTURE 23: OXIDATIVE PHOSPHORYLATION 25 OCT 2010
Background image of page 2
3 Krebs Cycle – Step 4 Oxidizes Z carbon from C=O to COO Releases CO 2 from Z, replaces with CoA thioester Makes NADH, releases energy (N.B. Not really an enol!) Oxidative Phosphorylation BCH 227 FALL 2010 LECTURE 23: OXIDATIVE PHOSPHORYLATION 25 OCT 2010
Background image of page 3

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

View Full DocumentRight Arrow Icon
4 NADH Energy • NADH has a reduction potential of -320 mV – under cellular conditions: -280 to -320 mV •O 2 is +816 mV •Δ for oxidation of NADH = 1.14 V •Δ for oxidation of NADH = -220 kJ/mol – cellular conditions: -212 to -220 kJ/mol • In cellular conditions, this would give 3-4 ATP NADH Energy • How to get ATP from NADH efficiently? BCH 227 FALL 2010 LECTURE 23: OXIDATIVE PHOSPHORYLATION 25 OCT 2010
Background image of page 4
5 NADH Energy Answer, Pt. 1: Extract energy in a series of small steps – Use metal cofactors with very small differences in reduction potential • Each step extracts a little bit of energy • Each step optimized to reduce waste – Arrange metals physically for optimized efficiency • Direct transfer of electrons avoids the waste of chemical reactions NADH Energy
Background image of page 5

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

View Full DocumentRight Arrow Icon
Image of page 6
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 22

Lecture23 - BCH 227 FALL 2010 LECTURE 23: OXIDATIVE...

This preview shows document pages 1 - 6. Sign up to view the full document.

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