Day 6 - Biosynthesis and Storage of Fatty Acids

Lipogenesis is under _______ control.

transcriptional

"this is the main take away from this slide" - Dr. Breakwell

When insulin is high, which is blocked, lipogenesis or ketogenesis?

ketogenesis

What moves acetyl-CoA from the matrix to the cytoplasm for fatty acid synthesis?

malate shuttle

What are the 2 major enzymes for fatty acid synthesis?

acetyl-CoA carboxylase (ACC) and fatty acid synthase

What enzyme aids in the formation of malonyl-CoA during fatty acid synthesis?

acetyl-CoA by acetyl-CoA carboxylase (ACC)

What enzyme aids in the elongation of fatty acid chain in 2-carbon increments during fatty acid synthesis?

fatty acid synthase

Lipogenesis is used to describe both _____ synthesis and _____ synthesis.

fatty acid

TAG

What is the step that is both rate-limiting and commits the cell to fatty acid synthase? (for sure on test)

ACC1

State where these enzymes occur and what they do:

1. ACC1:

2. ACC2:

1. cytoplasm, fatty acid synthesis

2. mitochondria, fatty acid oxidation

If citrate is high, energy storage is _______. If palmitoyl-COA is high, synthesis of FA is _______.

desirable

low

What 2 things does FA synthase include?

- acyl carrier protein (ACP)

- pantetheine group

Thioesters releases ______ carbon fatty acids.

16

Note: has to go through the cycle 6 times to achieve these 16 carbs

Do FA elongation and desaturation require and additional set of enzymes?

yes

What is released by FA synthase that is a substrate for the synthesis of longer chain fatty acids?

palmitate

What does fatty acid chain elongation depend on?

the addition of 2 carbon units from malonoyl-CoA.

______ and ______ acids are considered ESSENTIAL.

linolenic

linoelic

What are FAs stored as?

TAG

What hormone is the key to lipid catabolism vs anabolism?

insulin

Does insulin activate or inhibit ACC?

activate

When ACC is active, does lipogenesis or lipolysis occur?

lipogenesis (remember, insulin activates ACC)

When ACC is inhibited, does lipogenesis or lipolysis occur?

lipolysis (remember, insulin activates ACC, glucagon inhibits)

When insulin is high, does lipogenesis or lipolysis occur?

lipogenesis

When insulin is low, does lipogenesis or lipolysis occur?

lipolysis