BC10M: Introductory Biochemistry, 2005 Semester 2'

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BC10M Introductory Biochemistry, 2005 Semester 2.

• Tuesday 15 Mar.
• Lecture 24
• Lipid Metabolism
• Andrew Pearson

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Lipid function table
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(Singular mitochondrion)
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Mitochondria are present in most eukaryotic
cells. They are probably derived by a symbiotic
relationship arising from the invasion of a
eukaryote by a purple non-sulphur
bacterium. Oxidative phosphorylation takes place
using the inner membrane the Krebs cycle and
ß-oxidation of lipids occurs in the matrix.
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Within the matrix of the mitochondrion the Krebs
cycle and ß-oxidation (of lipids) give rise to
high energy reducing equivalents (electrons) that
enter the electron transport chain. These
are used to generate a proton motive force a
concentration gradient of protons across the
membrane which is used to drive the Fo/F1ATP
synthase (Complex 5)
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Krebs cycle, a.k.a. Tricarboxylic acid cycle
Citric acid cycle
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The purpose of the Krebs cycle is to extract the
maximum number of electrons from acetyl CoA, and
send them to the electron transport chain to
drive proton pumping. The purpose of the
ß-oxidation of lipids is to break down fatty
acids to electrons (to drive proton pumps) and
acetyl CoA (which then enters the Krebs cycle).
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Catabolism of all major food groups can lead to
Acetyl CoA
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(In Matrix)
( carrier)
Fatty acyl CoA dehydrogenase
Coenzyme A
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Squalene
Several steps
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Cholesterol