Unit 1 Flashcards
Biosynthesis of fatty acids (organ)
Liver
signal for activation of lipoprotein lipase
Apo C2
entry of glycerol into glycolysis
glycerol kinase, glycerol 3 p dehydrogenase, triose phosphate isomerase
Phospholipases
A1-bond between O and C of 1st chain
A2-bond between O and C of 2nd chain
C-bond between O and P of 3rd chain
D-cleaves head group
Lysophospholipase-cleaves O and C of 1st chain if the same from 2nd chain is already cleaved
FA oxidation
Mitochondria
FA biosynthesis
Cytoplasm
Acyl CoA Dehydrogenase
Dehydrogenation between alpha and beta carbon of acyl CoA
FADH2 is formed
Enoyl CoA hydratase
adds water and forms beta hydroxy enoyl coa
beta hydroxy acyl coa dehydrogenase
forms NADH and beta keto acyl coa
acyl coa acetyl transferase
cleavage forming acetyl CoA and acyl CoA
TFP sub unit
a subunit: enoyl-CoA hadratase and b-hydroxyacyl-CoA dehydrogenase
activities
b-subunit: thiolase ➔ substrate channeling
Dienoyl CoA reductase
in linoleic acid pathway
uses 1 NADPH
Epimerase
D-methyl malonyl CoA to L-methyl malonyl CoA
Mutase
requires vit B12
coverts L-methyl malonyl CoA to Succinyl CoA
FA oxidation regulation
- The three step process (carnitine shuttle) is rate-limiting for fatty acid oxidation
and is an important point of regulation - Malonyl-CoA, the first intermediate in the cytosolic biosynthesis of fatty acid
from acetyl-CoA, inhibits carnitine acyltransferase I. - [NADH]/[NAD+
] ratio is high, b-hydroxyl-CoA dehydrogenase is inhibited. - High concentrations of aceyl-CoA inhibit thiolase.
- [AMP] is high, AMPK is activated and phosphorylated acetyl-CoA
carboxylase, which catalyze the formation of malonyl-CoA, thereby decreasing
the malonyl-CoA concentration. ➔ allowing b-oxidation - Transcription factors turn on the synthesis
of proteins for lipid catabolism:
- PPARa acts in muscle, adipose tissue, and
liver to turn on a set of genes essential for
fatty acid oxidation.
- Glucagon ➔ [cAMP] ➔ CREB ➔ turn
on a set of genes essential for fatty acid.