Biochem - Fatty Acid Biosynthesis

Front 1

Citrate synthase

Back 1

Acetyl CoA + OAA -> Citrate

Front 2

ATP citrate lyase

Back 2

Citrate -> Acetyl CoA + OAA

*Requires ATP (ATP -> ADP)

Front 3

Malic enzyme

Back 3

Malate -> Pyruvate

Front 4

Biotin-dependent ATP carboxylase

Back 4

Acetyl CoA + bicarbonate -> Malonyl CoA

*Requires ATP (ATP -> ADP)

Front 5

Acetyl CoA:ACP transacetylase

Malonyl CoA:ACP transacetylase

Back 5

Acetyl/Malonyl CoA -> Acetyl-ACP, malonyl-ACP

Front 6

Ketoacyl ACP synthase

Back 6

Acetyl ACP + malonyl ACP -> acetoacetyl ACP + CO2

Front 7

Ketoacyl ACP reductase

Back 7

Acetoacetyl ACP -> D-beta-hydroxybutyrl ACP

*Converts NADPH to NADP+

Front 8

Beta-hydroxyacyl-ACP dehydrase

Back 8

D-beta-hydroxybutyrl ACP -> Trans-buteonyl ACP

*Converts NADPH -> NADP+

Front 9

Enol ACP reductase

Back 9

Trans-buteonyl ACP -> Butyryl ACP

Front 10

Thioesterase

Back 10

C16 Palmitate ACP -> Palmitate + ACP

Front 11

Briefly describe palmitate biosynthesis

Back 11

1. Acetyl CoA (cannot leave mitochondria) brought to cytosol via conversion with OAA to citrate (reconverted outside)

2. Acetyl CoA combines with bicarbonate to form malonyl CoA (pyruvate decarboxylase)

3. Acetyl, malonyl CoA both transacetylated to acetyl, malonyl ACP (acetyl/malonyl CoA:ACP transacetylase)

4. Acetyl and malonyl ACP combine to form aceteoacetate ACP (ketoacyl ACP synthase)

5. Aceotoacetyl ACP first reduced (C=O becomes OH), then dehydrated (becomes double bond) then reduced again (becomes single bond) to form butyryl ACP

6. Butyryl ACP combines with acetyl ACP, cycle continues until C16 reached

7. Palmitate (C16) cleaved from ACP by thioesterase

Front 12

What is the formula of palmitic acid (carbons)?

Back 12

C16

Front 13

What is the formula for palmitoleic acid? (carbons)

Back 13

C16;1 (9)

Front 14

What is the formula for stearic acid? (carbons)

Back 14

C18

Front 15

What is the formula for oleic acid? (carbons)

Back 15

C18;1 (9)

Front 16

What is the formula for linoleic acid? (carbons)

Back 16

C18;2 (9,12)

Front 17

What is the formula for linolenic acid? (carbons)

Back 17

C18;3 (9,12, 15)

Front 18

Stearoyl CoA desaturase

Back 18

Catalyzes desaturation reactions of palmitic and stearic acid, requires at least 6C from omega-carbon

Front 19

What is the reaction for elongation of fatty acids in mitochondria?

Back 19

Acyl CoA + Acetyl CoA -> (N+2C)-Acyl CoA

*Uses NADH or NADPH

Front 20

What is the reaction for elongation of fatty acids in the ER?

Back 20

Acyl CoA + Malonyl CoA -> (N+2C)-Acyl CoA

*Only uses NADPH

Front 21

Acyl CoA synthetase

Back 21

Fatty acid + ATP + CoA-SH -> Fatty acid CoA + AMP + PPi + H2O

*Activates fatty acid

Front 22

Glycerol-phosphate acyl transferase

Back 22

G3P (from DHAP) + 2 Fatty Acid-CoA -> Fatty Acid CoA-G3P-Fatty Acid CoA

*Product is phosphatidic acid
*Fatty acid attached to C1 is usually saturated, to C2 is usually unsaturated

Front 23

What is diacylglycerol?

Back 23

Intermediate in fatty acid synthesis, when phosphate group is removed from G3P (with two fatty acids already attached)

Front 24

What is triacylglycerol?

Back 24

= Triglyceride

Formed from addition of a third fatty acid to diacylglycerol