Lipogenisis (Chain Elongation - Kelly Notes)

Question 1

What is the cycle summary of Fatty Acid Chain Elongation?

Answer 1

x2 Carbon Units at a time, produce C16 Fatty Acid (Palmitate)

Question 2

What is the primary input for Fatty Acid Chain Elongation?

Answer 2

Acetyl CoA

Question 3

What activates the commitment step in Fatty Acid Chain Elongation & what is produced as a result?

Answer 3

Insulin activates to produce Malonyl CoA

Question 4

What enzyme is responsible for Fatty Acid Chain Elongation?

Answer 4

Fatty Acid Synthase (Multi-Enzyme Complex)

Question 5

What two molecules both combine to Fatty Acid Synthase to begin the process of Fatty Acid Chain Elongation?

Answer 5

Acetyl Cyst + Malonyl ACP

Question 6

The first step of Fatty Acid Synthase is known as what kind of reaction?

Answer 6

Condensation Reaction

Question 7

The 2nd step of Fatty Acid Synthase is known as what kind of reaction & what are its byproducts?

Answer 7

Hydrogenation (reduction)

NADH > NAD

Question 8

The 3rd step of Fatty Acid Synthase is known as what kind of reaction?

Answer 8

Dehydration

Question 9

The first step of Fatty Acid Synthase is known as what kind of reaction & what are its byproducts?

Answer 9

Hydrogenation (reduction)
NADH > NAD

Question 10

After the 4 steps of Fatty Acid Chain Elongation what happens?

Answer 10

The process repeats to add to the chain, adding to carbon units each cycle.

Question 11

Every time the Fatty Acid Chain Elongation sequence repeats, what molecule is needed?

Answer 11

Malonyl CoA

Question 12

What is the energy input for each chain elongation?

Answer 12

1 ATP molecule

Question 13

What is the first step of Fatty Acid Chain Elongation?

Answer 13

Acetyl CoA + Malonyl CoA = KetoAcyl-ACP

Question 14

What is the enzyme that converts Acetyl CoA + Malonyl CoA into KetoAcyl-ACP?

Answer 14

KetoAcel ACP Synthase

Question 15

What is the 2nd step of Fatty Acid Chain Elongation?

Answer 15

KetoAcyl-ACP is converted into HydroxAcyl-ACP

Question 16

What is the enzyme that converts KetoAcyl-ACP into HydroxAcyl-ACP?

Answer 16

KetoAcyl ACP Reductase

Question 17

During the 2nd step of Fatty Acid Chain Elongation, what are the byproducts from this reduction?

Answer 17

NADH > NAD

Question 18

What is the 3rd step of Fatty Acid Chain Elongation?

Answer 18

HydroxAcyl-ACP is converted into Trans-Enoyl-ACP

Question 19

What is the enzyme that converts HydroxAcyl-ACP into Trans-Enoyl-ACP?

Answer 19

HydroxyAcel ACP Dehydrogenase

Question 20

During the 3rd step of Fatty Acid Chain Elongation, what are the byproducts from this dehydration?

Answer 20

H20

Question 21

What is the 4th step of Fatty Acid Chain Elongation?

Answer 21

Trans-Enoyl-ACP is converted into Acyl-ACP

Question 22

What is the enzyme that converts Trans-Enoyl-ACP into Acyl-ACP?

Answer 22

Transenoyl Reductase

Question 23

During the 4th step of Fatty Acid Chain Elongation, what are the byproducts from this reduction?

Answer 23

NADH > NAD

Question 24

Which sequence # of chain elongations come to a conclusion?

Answer 24

7th Chain Elongation

Question 25

After step 4 of Fatty Acid Chain Elongation what happens & what is produced?

Answer 25

An additional Malonyl CoA is added and the process repeats to produce Palmitoyl ACP

Question 26

What total yield of inputs is required for Fatty Acid Chain Elongation to take place?

Answer 26

7 ATP (7 cycles)
14 NADH (x2 inputs per cycle)
8 Acetyl CoA (x1 per cycle + 1 extra to start the process)

Question 27

Before reaching the end-result of (16C) Palmitate, what enzyme converts what into Palmitate?

Answer 27

Thiosterase converts Palmitoyl ACP into Palmitate