3.6 FA synthesis

Question 1

Main site for de nove synthesis

Answer 1

Liver

Adipose Tissue

Question 2

Main precurosors for de novo synthesis

Answer 2

Carbohydrates (glucose)
Carbon skeleton of amino acids
Kreb’s cycle intermediates

Question 3

Structure of fatty acids

Answer 3

Hydrocarbon chains and a carboxyl end

Question 4

Rate limiting step of lipogenesis

Answer 4

Acetyl CoA to malonyl coa

Question 5

Converts pyruvate to acetyl coa

Answer 5

Pyruvate dehydrogenase

Question 6

Converts pyruvate to oxaloacetate

Answer 6

Pyruvate decarboxylase

Question 7

Formed as acetyl coa condenses with oxaloacetate

Answer 7

Citrate

Question 8

Cleaves citrate in the cytosol to reform acetyl coa and oxaloacetate

Answer 8

Citrate lyase

Question 9

Converts cytosolic acetyl coa to malonyl coa

Also the rate-limiting step in lipogenesis

Answer 9

Acetyl CoA carboxylase

Question 10

Sources of NADPH

Answer 10

Pentose Phosphate Pathway

Reduction of cytosolic malate by malic enzyme

Question 11

NADPH produces in PPP and malic enzyme reaction

Answer 11

PPP: 6 NADPH (3 glucose X 2 NADPH per glucose)

Malic Enzyme: 1 molecule of each cycle of citrate cleavage

Question 12

Preferred product of FA syntheses

Answer 12

Palmitate

Question 13

Where the carboxyl end of palmitate came from

Answer 13

Malonyl CoA

Question 14

Locations for elongation of palmitate

Answer 14

Smooth ER

Mitochondria

Question 15

Fatty acid desaturation occurs in the

Answer 15

Endoplasmic reticulum