Brainscape's Knowledge GenomeTM

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


See full index

MCBM > Lipid synthesis > Flashcards

Lipid synthesis Flashcards

1
Q

Synthesis of palmitate:

A

Has 16 carbons. Primary FA that we make; no DB’s, fully saturated.

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

Where does most fatty acid synthesis take place

A

liver;

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

What does excess acetylCoA convert to?

A

Fatty acid esters which are our triglycerides. This occurs in the CYTOPLASM

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

What does fatty acid synthesis require

A
  1. ATP
  2. NADPH
  3. acetlCoA carboxylase; our rate limiting step
  4. Fatty acid synthase (large multisubunit complex)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Where do we get NADPH for FA synthesis

A
  1. PPP pathway

2. malic enzyme –>converts malate directly to pyruvate and in so doing makes NADPH

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

What is the first step of palmitate synthesis

A

Synthesis of MalonylCoA; acetylCoA with CO2 stuck on end. Biotin associated attached with lysine. This makes malonylCoA. The synthesis of malonylCoA requires acetylCoA carboxylase, biotin and ATP

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

What is step 2

A
  1. Malonyl CoA binds to acyl carrier protein

2. Acetyl group from acetyl CoA attaches to KS.

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

What are the 4 steps of elongation

A
  1. Condensation: acetyl group transferred to malonyl group on ACP; CO2 is released
  2. Reduction: NADPH is used to reduce aldehyde to alcohol
  3. Dehydration: water is removed to form DB
  4. Reduction: NADPH is used to reduce DB
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What does malonyl acetyl transferase do

A

Takes 4 carbon unit from ACP and transfers it to KS; leaves ACP empty for new malonyl CoA to come in.

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

Which enzyme is responsible for condensation

A

KS

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

Which enzyme is responsible for reduction

A

KR

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

Which enzyme is responsible for dehydration

A

DH

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

Which enzyme is responsible for second reduction

A

ER

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

What is being produced in the first round of palmitate synthesis

A

4C acyl chain

  • Then 6 more rounds that each add 2 C to make a total of 16
  • Total of 7 rounds
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is overall being produced

A

7 malonylCoA
7 ATP
14 NADPH

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

Where does the conversion of palmitate to other FA’s occur

A

smooth ER

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What does elongation require in order to convert palmitate to other FA’s

A
  1. palmitoylCoA with no ACP and malonylCoA
  2. NADPH
  3. stearic acid
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

how many carbons in stearic fatty acid

A

18- no double bonds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

what does desaturation require (prod DB)

A

oxygen, NADH and cytochrome b5, DB usually occurs at number 9 position

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is the rate limiting step

A

adding acetylCoA carboxylase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Most of acetyl CoA we make is in:

A

mitochondria; no mitochondrial transporters; so you have to convert them to citrate to make it go to cytoplasm for FA synthesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

How is citrate formed

A

oxaloacetate + acetyl CoA; citrate lyase converts it back to ^

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What activates citrate lyase

A

insulin; its our fed hormone and we want to store energy as fat; so we convert it to tryglycerides and send it to adipose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Glucagon and ___inhibit process

A

epinephrine

25
Q

How do you make glycerol - 3-phosphate

A
  1. In liver, glycerol is taken up and adds ATP via glycerol kinase–>glycerol3phosphate
  2. In adipose: goes through dihydroxyacetone phosphate and needs NADH to make glycerol-3-phosphate
26
Q

what is precursor of triglycerides

A

glycerol 3 phosphate

27
Q

Synthesis of triglycerides:

Triacylglycerol and Phosphatidic Acid

A
  1. Long chain fatty acylCoA’s are substrates to add FA’s at carbon 1 and 2 via acyl-CoA synthetase. This requires ATP
  2. Phosphatidic acid phosphatase removes phosphate; acyl transferase adds 3rd FA to form triacyglcerol; addition of each FA requires 2 high energy bonds
28
Q

what are the broken down steps to make triacylglycerols

A
  1. glucose + aa –> acetyl coA via activation of insulin to activate glycolysis
  2. Acetyl cOA converts to malonyl CoA makes fatty acids
  3. Fatty acids make triacylglycerols
29
Q

What is lipoprotein lipase

A

activated by insulin; binds to lipoproteins and cleaves off lipids from triglyceride and releases glycerol back in to bloodstream which goes back to liver which can be made into glycerol 3 phosphate to make more triglycerides. Free FA come into adipose to combine with triacylcerols for storage

30
Q

What are the different things that can be attached to polar head group of phospholipids

A
  1. Serine
  2. Ethanolamine
  3. Choline
  4. Glycerol
  5. Inositol
  6. cardiolipid
31
Q

What are two strategies to attach head groups

A
  1. Diacylglycerol activated with CDP and then stick on glycerol, inositol, or cardiolipin
  2. Head group activated with CDP; ethanolamine or choline
32
Q

Phosphatidylserine is made via ___exchange

A

base; with PE or PC

33
Q

Phosphatidylcholine is made from

A

PE; which is made from CDP choline +DAG or methylation of PE

34
Q

Phosphatdilethalamine is made from

A

CDP-ethanolamine +DAG

35
Q

Sphingolipids have ___backbone

A

serine

36
Q

PalmitoylCoA + serine=

A

sphingosine + CO2

37
Q

Sphingosine + acetylCoA =

A

ceramide + CoA

38
Q

Ceramide + PC=

A

sphingomyelin +DAG

39
Q

Ceramide + UDP-glucose =

A

cerebroside +UDP

40
Q

multiple sugars =

A

globoside; blood group antigens

41
Q

Sphingosine are:

A

Serine backbone with palmitoyl CoA

42
Q

Ceramide can convert to cerebroside or ____

A

sphingomyelin

43
Q

What are four major stages of cholesterol synthesis

A
  1. Condensation:3 Acetyl CoA to make mevalonate + CoA
  2. Formation of activated isoprene: via mevalonate +3 ATP
  3. Polymerization: squalene + 6 CO2
  4. cyclization &transformation: end up with cholesterol
44
Q

What makes ketone bodies

A

HMG CoA lyase

45
Q

What is the committed step in cholesterol synthesis

A

HMG CoA reductase; activated by insulin, and blocked by glucagon.

46
Q

What is found in fungal pathogens

A

Engosterol

47
Q

Cholesterol head groups get masked so it becomes ____so it could get stored. They do this by forming ____

A

hyrophobic; esters

48
Q

What does ACAT do

A

Enzyme to make cholesterol esters from cholesterol.

49
Q

Prostaglandins and thromboxanes are made from an enzyme called:

A

prostaglandin endoperoxide synthase (COX)

50
Q

What are the two catalytic activities of prostaglandin enderoperoxide synthase

A
  1. cyclooxygenase

2. peroxidase

51
Q

What are the end products of eicosinoids

A
  1. Prostaglandins
  2. Thromboxane
  3. Leukotriene
52
Q

What inhibits phospholipase A2

A

Cortisol

53
Q

WHat is Cox1

A

Made all the time in most cells. Required for gastric tissue, renal homeostatsis, and platelet aggregation

54
Q

What is Cox 2

A

Inducible in response to inflammation; PGs mediate pain, heat, redness, swelling of inflammation.

55
Q

What inhibits both Cox1 and Cox2

A

Aspirin and indomethacin

56
Q

What do Cox2 inhibitors cause

A

clots; production of thromboxane A2, and loss of production of PGI2

57
Q

There are ___lipoxygenase inhibitors and leukotriene receptor antagonists are used to treat

A

5; asthma

58
Q

what makes leukotrienes

A

lipoxygenase

MCBM (59 decks)

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