Cell Metabolism 2 - Lipogenisis

Question 1

Fatty acid biosynthesis - Lipogenesis

Answer 1

2 enzymes: Acetyl CoA Carboxylase + Fatty acid synthase

Acetyl CoA + Malonyl CoA undergo decarboxylative condensation reactions —> form fatty acids

1. Round of elongation
2. Reduction and dehydration by sequential action of ketoreductase, dehydratase and enrol reductive activity

Growing fatty acyl group linked to acyl carrier protein

Question 2

Similarities between synthesis and degradation

Answer 2

Carriers: ACP vs CoA

Reducing Power: NADPH vs FAD/NAD+

Locations: Cytoplasm vs Mitochondrial Matrix

Question 3

Fatty acid synthesis in cancer

Answer 3

Adult —> de novo FA biosynthesis restricted mainly to liver, adipose tissue and lactating breasts

Reactivation of FA biosynthesis also occurs in certain cancer cells

Question 4

Medium chain acyl-CoA dehydrogenase deficiency (MCADD)

Answer 4

Can’t rely of ability to produce fatty acids

Autosomal recessive —> predominately Caucasians

Should never go without food for longer than 10-12hrs
—> high carbohydrate diet

Patients with illness resulting in appetite loss or severe vomiting —> IV glucose so body is not dependent on fatty acids for energy