This preview shows page 1. Sign up to view the full content.
Unformatted text preview: ists said wouldn’t work.” Peter Mitchell
1920-1992 Nobel Prize 1978 Peter Mitchell (1961). "Coupl i ng of phosphoryl ati on to electron and
hydrogen transfer by a chemi-osmotic type of mechanism". Nature 191:
144–148 Chemiosmosis Ef Racker
Efraim Racker (1913-1991), a biochemist at
Cornell University was the first to purify the F1
particle (ATP synthase catalytic knobs) from
the mitochondrial membrane. Along with
Cornell’s Andre Jagendorf, and Peter Hinkle,
he studied its function in an artificial membrane
Electron transport chain chemiosmosis CHEMIOSMOSIS Support for Chemiosmosis Hypothesis ATP SYNTHASE 1. pH in intermembrane space of the mitochondrion is lower
than outside. (A proton-powered motor
for generating ATP) 2. A proton gradient is all that is necessary for ATP synthesis.
Electron transport is not required.
Reconstitution experiment: artificial ATP synthesis
Racker & Stoeckenius:
ATP synthesis in artificial system with three components
(1) artificial membrane vesicles
(2) isolated mitochondrial particles from beef heart
(3) bacteriorhodopsin (H+ pump activated by light). How ATP Synthase works Summary of electron transport
and chemiosmosis Nobel Prize 1997 i ntermembrane space matrix Paul Boyer John W alker
space F0 matrix F1 Yield from aerobic catalysis of glucose What if there is no oxygen ? Fermentation reactions allow ATP to be
generated in the absence of oxygen Fermentation reactions allow ATP to be
generated in the absence of oxygen Yeast
_ Clicker question Since Bacteria and Archaea lack organelles,
do they perform oxidative phosphorylation ?
A. No, they typically live in anaerobic environments
B. Yes, with their mitochondria like protists do
C. No, they only perform glycolysis
D. Yes, with electron transport proteins on the inner
surface of their plasma membrane
E. No, but many perform fermentation Other compounds can be substrates
for cellular respiration
= OH S-CoA oxidation of fatty acids
2 carbons at a time
in the mitochondrial matrix 2 Next up - Photosynthesis...
View Full Document
This note was uploaded on 12/21/2012 for the course BIOMG 1101 taught by Professor Colegilbert during the Fall '09 term at Cornell University (Engineering School).
- Fall '09