7: Biochemistry - Lipid anabolism Flashcards Preview

Gastrointestinal Week 1 2016/17 > 7: Biochemistry - Lipid anabolism > Flashcards

Flashcards in 7: Biochemistry - Lipid anabolism Deck (26)
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1
Q

In lipid metabolism, dietary energy is converted into stored ___.

A

fat

2
Q

What is lipogenesis?

A

Fatty acid synthesis

3
Q

Lipogenesis takes place during (insufficient / excess) energy intake.

A

excess

4
Q

In lipogenesis, carbohydrate is converted to which lipids?

A

Fatty acids

Triglycerides

5
Q

Which molecule carries triglycerides to adipose tissue?

A

VLDL

6
Q

Which protein carries free fatty acids in the plasma?

A

Albumin

7
Q

Where does lipogenesis primarily occur?

A

Liver

8
Q

Lipogenesis is a (oxidative / reductive) process.

A

reductive

9
Q

What is the precursor molecule for lipogenesis?

A

Acetyl-CoA

10
Q

Fatty acid breakdown to Acetyl-CoA occurs in the (cytoplasm / mitochondrial matrix).

Fatty acid synthesis from Acetyl-CoA occurs in the (cytoplasm / mitochondrial matrix).

A

mitochondrial matrix

cytoplasm

11
Q

Which molecule, usually generated in the TCA cycle, transports acetyl groups into the cytoplasm?

A

Citrate

12
Q

Before Acetyl-CoA can convert lipids to carbohydrate, it has to be activated. Which enzyme activates Acetyl-CoA?

A

Acetyl-CoA carboxylase

13
Q

What is formed by the activation of acetyl-CoA by acetyl-CoA carboxylase?

A

Malonyl-CoA

14
Q

What is the essential regulatory enzyme for the first step of lipogenesis?

A

Acetyl-CoA carboxylase

15
Q

What is the activated form of acetyl-CoA which donates a carbon atom to the lipid?

A

Malonyl-CoA

16
Q

Which enzyme catalyses the synthesis of long chain fatty acids from malonyl-CoA, acetyl-CoA and NADPH?

A

Fatty acid synthase

17
Q

Which protein carries the growing fatty acid chain until sufficient carbon atoms have been added to it?

A

Acyl-carrier protein (ACP)

18
Q

What donates electrons to the growing fatty acid chain during lipogenesis?

A

NADPH

19
Q

When the length of __ carbons is reached, the newly synthesised fatty acid is released from ACP.

A

16

20
Q

What is the regulatory enzyme in lipogenesis?

A

Acetyl-CoA carboxylase

21
Q

Which hormone, which signals the fed state, stimulates the activity of acetyl-CoA carboxylase?

A

Insulin

22
Q

Which hormone, which signals the starved state, inhibits the activity of acetyl-coA carboxylase?

A

Glucagon

23
Q

What is a hormone, other than glucagon, which inhibits the action of acetyl-CoA carboxylase and therefore lipogenesis?

A

Adrenaline

24
Q

The concentration of which molecule acts allosterically to switch off lipogenesis when it is high?

A

Citrate

25
Q

Which activated form of glycerol is required for triglyceride synthesis?

A

Glycerol-3-phosphate

26
Q

In which form is fat stored in adipose tissue?

A

As triglycerides