2.6 Fatty Acid Biosynthesis

Question 0

What is the main substrate for synthesis?

Answer 0

Acetyl CoA

Question 1

Where does Fatty Acid Biosynthesis occur?

Answer 1

Cytosol of Liver

Question 2

How does Acetyl CoA move across the mitochondrial membrane?

Answer 2

Acetyl CoA + Oxaloacetate = Citrate

Citrate can be moved across the membrane

Question 3

What enzyme catalyzes reaction of Acetyl CoA and Oxaloacetate to Citrate

Answer 3

Citrate Synthase

Question 4

What enzyme catalyzes the reaction that occurs to take Citrate to Acetyl CoA and Oxaloacetate

Answer 4

Citrate Lyase

Question 5

What 3 things regulate FA biosynthesis

Answer 5

High Citrate
High ATP
High Acetyl CoA

Question 6

WHat enzyme catalyzes reaction of Acetyl CoA to Malonyl CoA

Answer 6

Acetyl CoA Carboxylase

Question 7

What is the coenzyme in the reaction of acetyl CoA to Malonyl COA

Answer 7

Biotin

Question 8

What is the rate limiting step of FA biosynthesis

Answer 8

Acetyl CoA –> Malonyl CoA

Question 9

Carboxylation reactions require what three things?

Answer 9

Biotin
ATP
CO2

Question 10

How is Acetyl CoA Carboxylase activated?

Answer 10

PP2A dephosphorylates Acetyl CoA Carboxylase

Question 11

What three things regulate Acetyl CoA Carboxylase

Answer 11

High levels of AMP deactivate
High levels of Insulin
Low levels of Glucagon and Epinephrine

Question 12

T or F, High levels of Citrate promote FA biosynthesis

Answer 12

True

Question 13

Low levels of Malate and Epinephrine do what to Acetyl CoA Carboxylase?

Answer 13

They Activate the enzyme and therefore promote FA synthesis.

Question 14

What are the normal substrates to form a Palmitate molecule

Answer 14

8 Acetyl CoA, 14 NADPH, 7 ATP, 14 H+

Question 15

What four reactions are involved in Fatty Acid synthesis

Answer 15

Condensation –> Reduction –> Dehydration –> Reduction

Question 16

In what two pathways does the NADPH come from that helps FA Synthesis

Answer 16

Pentose Phosphate Pathway

Malate to Pyruvate

Question 17

What do you lose when Acetyl CoA is added to Malonyl CoA

Answer 17

CO2 (condensation)

Question 18

When the four carbon unit is removed from ACP and moved to CE acp, what is needed?

Answer 18

2 NADPH

Question 19

Where does Fatty Acid ELongation occur?

Answer 19

on the cytoplasmic face of ER

Question 20

What enzyme is involved in Fatty Acid Elongation

Answer 20

Fatty Acid Elongase

Question 21

Fatty Acid Desaturation takes place where and by what enzyme?

Answer 21

In the ER

Fatty Acid Desaturase

Question 22

What are the essential precursors of TAGs

Answer 22

G3P
DHP (Dihydroxyacetone Phosphate)
FFA
Phosphatidate

Question 23

Where are TAGs synthesized

Answer 23

Liver and Adipose tissue

Question 24

Why are TAGs only made in adipose in the Fed state when glucose available

Answer 24

Because adipose tissue does not have the enzyme glycerol kinase and needs a rich supply of glucose available