E2: fatty acid, triglycerides + phospholipids synthesis

fatty acid synthesis

• in cytoplasm NOT Mitochondria

mt matrix: acetyl coa > krebs cycle > citrate some finishes cycle + other > cytoplasm

cytoplasm: citrate + ATP + CoASH > acetyl coA + ADP + Pi + oxaloacetate (back to krebs cycle)

citrate cleaving enzyme

catalyzes rxn of citrate > acetyl coA + oxaloacetate

need citrate to bring actyl coa to the cytoplasm

malonyl CoA

needed in addition to acetyl coA for fatty acid synthesis

acetyl coA carboxylase

allosteric enzyme that converts acetyl coa to malonyl coa

positive: citrate (excess > FA synthesis)

biotin cofactor

fatty acid synthetase complex

consists of acyl carrier protein that has phosphopantetheine cofactor

FA breakdown vs synthesis

breakdown

• mt matrix

• fatty acid- COA

• L alcohol

• NAD+ + FAD+

synthesis

• cytoplasm

• acyl carrier protein ( can only make palmitic acid 16c saturated FA)

• malonyl Coa

• D alcohol

• NADPH

cytochrome B5

can only add double bond up to C9 to any FA with coa attached

CIS double bond

uses NADPH + o2

essential fatty acids

1. linoleic acid

   • 18C 2 cis double bonds 9 + 12

2. linolenic acid

   • 18C 3 cis DB 9, 12, 15

STUDY PG 11-16 for biosynthesis of triglycerides + phospholipids

lipid storage diseases

• hereditary

• caused by making too many lipids or not breaking them down > build up

Tay Sachs disease

• defective gene from both parents

• mental impairment = blindness

• cant break down gangliosides

  • GM2 enzyme defect