Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

1. Theme 3 > T3 L15: Lipid metabolism and pathways > Flashcards

T3 L15: Lipid metabolism and pathways Flashcards

1
Q

What are the 3 steps for oxidation of triglycerides?

A
  1. Glycerol is removed and the fatty acid chain is oxidised into 2-carbon fragments in the form of acetyl CoA
  2. Acetyl-CoA is oxidised to CO2 in the citric acid cycle
  3. e- are transferred in the e- transport chain
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is Beta-oxidation?

A

The removal of glycerol and oxidation of long fatty acids into acetyl CoA from a triglyceride

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Where does Beta-oxidation occur?

A

In the mitochondria and peroxisomes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is acetyl-CoA made of?

A

An acetyl group from the fatty acid and CoA that bond together during beta-oxidation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What does each cycle of beta-oxidation produce?

A

1 acetyl CoA, 1 FADH2, and 1 NADH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Where does fatty acid synthesis occur?

A

In the cytosol of hepatocytes and adipocytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Where is acetyl CoA found in a cell?

A

In the mitochondria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Which process makes acetyl CoA leave the mitochondria?

A

The citrate malate cycle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the rate-limiting step of the citrate malate cycle?

A

Carboxylation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the rate limiting step of beta-oxidation?

A

The transfer of acetyl-CoA into mitochondria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is formed during fatty acid synthesis?

A

Malonyl-CoA from acetyl-CoA, catalysed by acetyl-CoA carboxylase. This is subject to control by insulin and glucagon

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are the physiological roles of cholesterol?

A

For membranes, precursor of steroid hormones, source of bile acid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are the physiological roles bile acids?

A

Lipid digestion, lipid absorption, cholesterol excretion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is an amphipathic lipid and what is it made from?

A

It has both hydrophobic and hydrophilic portions and is synthesised from acetyl-CoA and bile acids. It’s the storage form of cholesterol in most tissues

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the rate determining step of cholesterol biosynthesis?

A

2nd bit where HMG-CoA is made into Mevalonate using HMG-CoA reductase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Which hormones control the activity of HMG-CoA reductase?

A

Insulin and glucagon

17
Q

What is the function of albumin?

A

Its a transporter protein that circulates in the blood

18
Q

What is the function of lipoproteins?

A

They carry insoluble proteins

19
Q

Describe the structure of a lipoprotein

A

The insoluble lipids will be carried in the centre, and the out layer is made of amphipathic phospholipids and cholesterol

20
Q

What is IDL?

A

Intermediate density lipoprotein

21
Q

Order these from least dense to most dense: VLDL, LDL, HDL, and IDL

A

VLDL, IDL, LDL, and HDL

22
Q

What is the function of chylomicrons?

A

They deliver dietary triglycerides to muscles and adipose tissue and they carry dietary cholesterol to the liver

23
Q

What does VLDL carry?

A

transports endogenous triglycerides and cholesterol

24
Q

What does LDL carry?

A

Transports cholesterol from the liver to tissues

25
Q

What does HDL carry?

A

transports cholesterol from tissues to liver (removes cholesterol from tissues), AKA reverse cholesterol transport

26
Q

How does IDL form?

A

When VLDL becomes depleted of lipids

27
Q

What does lipoprotein lipase do?

A

Releases triglycerides from chylomicrons and VLDL at tissues (they are bound to tissues)

28
Q

How does the liver recognise remnants of lipids?

A

Using their ApoE (Apolipoprotein E) content found on all but LDL

29
Q

How is LDL recognised?

A

By cell surface LDL receptors (LDLR’s) because LDL has ApoB-100 so it can’t be recognised like other lipoproteins

30
Q

How are LDL receptors regulated?

A

By SREMP transcription factors and PCSK9 which causes degradation of LDL receptors

31
Q

What is the function of ABCA1 and ABCA8?

A

They allow cholesterol excretion from cells

1. Theme 3 (19 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions