Krebs Cycle - Molecular Biochemistry I Pyruvate...

Info iconThis preview shows pages 1–8. Sign up to view the full content.

View Full Document Right Arrow Icon
Pyruvate Dehydrogenase Copyright © 1999-2006 by Joyce J. Diwan. All rights reserved. Molecular Biochemistry I
Background image of page 1

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

View Full DocumentRight Arrow Icon
w The matrix contains Pyruvate Dehydrogenase , enzymes of Krebs Cycle , and other pathways, e.g., w The outer membrane contains large VDAC channels, similar to bacterial porin channels, making the outer membrane leaky to ions & small molecules. matrix inner membrane outer membrane inter- membrane space mitochondrion cristae Glycolysis occurs in the cytosol of cells. Pyruvate enters the mitochondrion to be metabolized further. Mitochondrial Compartments:
Background image of page 2
It contains various transport catalysts , including a carrier protein that allows pyruvate to enter the matrix. It is highly convoluted, with infoldings called cristae . Embedded in the inner membrane are constituents of the respiratory chain and ATP Synthase . matrix inner membrane outer membrane inter- membrane space mitochondrion cristae The inner membrane is the major permeability barrier of the mitochondrion.
Background image of page 3

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

View Full DocumentRight Arrow Icon
Pyruvate Dehydrogenase , catalyzes oxidative decarboxylation of pyruvate, to form acetyl-CoA. H 3 C C C O - O O C S O H 3 C CoA HSCoA NAD + NADH + CO 2 Pyruvate Dehydrogenase pyruvate acetyl-CoA
Background image of page 4
w The inner core of mammalian Pyruvate Dehydrogenase is an icosahedral structure consisting of 60 copies of E2 . w At the periphery of the complex are: 30 copies of E1 (itself a tetramer with subunits α 2 β 2). 12 copies of E3 (a homodimer), plus 12 copies of an E3 binding protein that links E3 to E2. Pyruvate Dehydrogenase: a large complex containing many copies of each of 3 enzymes, E1 , E2 , & E3 .
Background image of page 5

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

View Full DocumentRight Arrow Icon
Pyruvate Dehydrogenase Subunits Enzyme Abbreviated Prosthetic Group Pyruvate Dehydrogenase E 1 Thiamine pyrophosphate (TPP) Dihydrolipoyl Transacetylase E 2 Lipoamide Dihydrolipoyl Dehydrogenase E 3 FAD
Background image of page 6
FAD ( F lavin A denine D inucleotide is derived from the vitamin riboflavin. The dimethylisoalloxazine ring system undergoes oxidation/reduction. FAD is a prosthetic group, permanently part of
Background image of page 7

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

View Full DocumentRight Arrow Icon
Image of page 8
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 23

Krebs Cycle - Molecular Biochemistry I Pyruvate...

This preview shows document pages 1 - 8. Sign up to view the full document.

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