Brainscape's Knowledge GenomeTM

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


See full index

Cellular Processes > Fatty Acid Synthesis > Flashcards

Fatty Acid Synthesis Flashcards

1
Q

Where in the body is lipogenesis particularly important?

A
  • Adipose
  • Liver
  • Lactating mammary
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Where does lipogenesis occur?

A

In the cytoplasm

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

Where is acetyl-CoA made?

A

In the mitochondria

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

How is acetyl-CoA transported into the cytosol?

A

Via the citrate shuttle

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

Which enzyme catalyses the formation of malonyl-CoA from acetyl-CoA?

A

Acetyl-CoA carboxylase

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

What acts as a cofactor for Acetyl-CoA carboxylase?

A

Biotin

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

Give the reaction for the carboxylation of acetyl-CoA to form malonyl-CoA

What is often the source of CO2 in this reation?

A

acetyl-CoA + CO2 + ATP → malonyl-CoA + ADP + Pi

Usually comes from bicarbonate

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

Which enzyme is responsible for the synthesis of fatty acids?

A

Fatty Acid synthase

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

Where do acetyl-CoA and malonyl-CoA bind on fatty acid synthase?

A

Bind to sulphydryl group of an acyl carrier protein

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

Overall how many NADPH are required to produce 1 molecule of palmitate?

A

14

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

Where is palmitate further elongated and desaturated?

A

Smooth endoplasmic reticulum

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

What happens to the fatty acid when a 16 carbon fatty acid chain is formed?

A

It drops off fatty acid synthase

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

How is fatty acid synthesis regulated in the short term?

A
  • Control of pyruvate dehydrogenase and glucose uptake controls substrate supply
  • Inhibition/activation of acetyl-CoA carboxylase
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What allosterically activates Acetyl-CoA carboxylase?

A

Citrate

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

What inhibits Acetyl-CoA carboxylase?

A

Palmitoyl-CoA

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

Which enzymes are regulated in the long term via hormonal and nutrient control?

A
  • Acetyl-CoA carboxylase
  • Fatty acid synthase
  • Pentose phosphate pathway enzymes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What kind of diet induces expression of Acetyl-CoA carboxylase?

A

High carb

18
Q

What is cholesterol synthesised from?

A

Acetyl-CoA

19
Q

Which enzyme is involved in the production of cholesterol?

A

HMG-CoA reductase

20
Q

How is HMG-CoA reductase regulated in the short term?

A

End product allosteric inhibition by cholesterol

21
Q

How is HMG-CoA reductase regulated in the long term?

A

Cholesterol inhibits expression of HMG-CoA (at a gene level)

22
Q

What drugs inhibit HMG-CoA reductase?

A

Statins

23
Q

How are lipids transported into the blood?

A

In association with proteins as lipoprotein particles

24
Q

What makes up lipoproteins?

A
  • Cholesterol
  • Apolipoproteins
  • Phospholipids
  • Triacylglycerol and cholesteryl esters
25
Q

What are the roles of apolipoproteins?

A
  • Structural
  • Ligands for receptors
  • Activators for enzymes involved in metabolism of lipoprotein particles
26
Q

Where are chylomicrons formed in exogenous lipid transport?

A

In cells that line the gut

27
Q

Which apoproteins are transported onto chylomicrons in the exogenous lipid transport mechanism?

A

C11 and E

28
Q

What is the purpose of C11 in the exogenous lipid transport pathway?

A

Activates lipoprotein lipase on the surface of capillaries causing the hydrolysis of TAGs to glyceol and non-esterified fatty acids

29
Q

What is the purpose of Non-essential fatty acids?

A

They enter cells fro metabolism/storage

30
Q

What happens to C11 once it has activated lipoprotein lipase?

A

It is transferred back to HDL

31
Q

Why does the proportion of cholesterol increase in remnant chylomicron?

A

due to the depletion of triglycerides

32
Q

Where is the CM remnant taken up?

A

In the liver

33
Q

Which receptors in the liver allow CM remnant to be taken up?

A

B48 and E

34
Q

In endogenous lipid transport what picks up lipoproteins from HDL?

A

VLDL

35
Q

In the circulation what does IDL become?

A

LDL

36
Q

What type of lipoprotein can be taken up by the unregulated cholesterol pathway?

A

Modified LDL

37
Q

What controls the expression of the gene for LDL receptor?

A

The amount of cholesterol in the cell

38
Q

What are the functions of HDL?

A
  • Provides apoproteins for other lipoproteins
  • Mops up cholesterol from peripheral tissues
39
Q

What can hyperlipidaemias occur as a result of?

A
  • enzyme deficiency
  • apoprotein deficiency
  • receptor deficiency
40
Q

What type of immune cell is involved in atherosclerosis?

A

Macrophages

41
Q

What do macrophages ingest in the process of atherosclerosis?

A

Oxidised lipoproteins

42
Q

Outline the process of atherosclerosis

A
  • oxidised lipoproteins aggregate and stick to the extracellular matrix
  • Macrophages are attracted and ingest lipoproteins
  • Free cholesterol accumulates in macrophages
  • Apoptosis, necrosis and tissue damage occurs
  • A cholesterol-rich plaque forms

Cellular Processes (22 decks)

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