Lipogenesis Flashcards
What is lipogenesis?
Fatty acid biosynthesis.
How many enzymes are used for lipogenesis? What are they?
Two enzymes:
Acetyl CoA carboxylase;
Fatty Acid Synthase.
What sort of reactions take place to form the fatty acids? What molecules are involved?
Decarboxylative condensation reactions involving the molecules acetyl CoA and malonyl CoA.
Following each round of elongation, the fatty acid undergoes reduction and dehydration reactions by what enzymes?
Ketoreductase (KR), dehydratase (DH) and enol reductase (ER).
The growing fatty group is linked to what?
An acyl carrier protein ACP.
If a fatty acid is longer than 16 carbons long, where does elongation occur?
ER/mitochondria
Where does lipogenesis occur?
Cytoplasm.
What carrier does beta-oxidation use compared to lipogenesis?
BO uses CoA whereas synthesis uses ACP.
What reducing agent is used in BO compared to lipogenesis?
What general rule does this show?
BO uses FAD/NAD+ (generating NADH) while synthesis uses NADPH.
NADPH generally is for synthesis while NAD+/FAD are generally for energy-yielding reactions as they form NADH and FADH2 respectively.
Where does BO occur?
Mitochondrial matrix.
What enzyme creates oleic acid and palmitoleic acid from stearate and palmitate respectively?
Delta-9 desaturase - it generates a double bond nine carbons from the terminal carboxyl group.
Where does de novo biosynthesis mainly restricted to in adults?
The liver, adipose tissue, and lactating breasts.
What is the link between lipogenesis and cancer?
Evidence suggests that reactivation of FA synthesis occurs also in certain cancer cells.
Inhibition of FA synthesis by cerulenin (an antifungal antibiotic) is shown to reduce tumour growth of ovarian cancer cells.
