Brainscape's Knowledge GenomeTM

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


See full index

DMD 5242 > Fatty Acid Metabolism > Flashcards

Fatty Acid Metabolism Flashcards

1
Q

Where does B oxidation occur?

A

Matrix

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

Can large FA transport easily into matrix?

A

No, need acyl-carnitine/carnitine transporter

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

Basic B oxidation mechanism

A

FADH2 reduces alpha and beta carbon = double bond
H2O hydrates the beta C
NADH reduces the hydroxyl to a carbonyl
CoASH attacks, kicking off 2 Cs (acetyl CoA)

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

Type of double bond created in B oxidation

A

Trans

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

Acyl CoA DH

A

First enzyme in B ox

On IMM, transfers e- from FADH2

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

Enoyl CoA hydratase

A

2nd enzyme in B ox

Adds water

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

What does a flavin look like?

A

3 ring chain
Attaches to FAD complex at N in the middle ring
Reducing H’s attach at the other N in middle ring and at N on the oxygenated outer ring?

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

B-hydroxyacyl-CoA dehydrogenase

A

3rd step of B ox

Reduces hydroxyl group with NADH

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

Thiolase

A

Last step of B ox

Adds CoASH to B carbon

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

Total ATP for palmitic acid

A

108, net 106

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

How do you B ox an unsaturated FA?

A

B ox until you hit the double bond
Isomerase will convert cis to trans bonds at carbon 3
Reductase will reduce cis to trans not carbon 3

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

How do you B ox a FA with an uneven amount of c’s?

A

Get down to propionyl-CoA
PropionylCoA carboxylase will add CO2 to c2 with biotin
MethylmalonylCoA epimerase will switch C1 withe new CO2
MethylmalonylCoA mutase will radically shift CoA to the C4 position with B12 to get succinylCoA

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

What is so great about B12?

A

Can catalyze stable radical reactions, like epimerization reactions

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

When are ketone bodies made?

A

During starvation

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

Why are ketone bodies important?

A

Can be used as metabolic fuel from acetyl-CoA when OAA is depleted

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

Briefly explain ketogenesis

A

B hydroxybutyrate is dehydrated with NAD+
SuccinylCoA donates CoA making acetyoacetylCoA and succinate
CoASH is cleaved off with thiolase and you’re left with 2 acetyl CoA

17
Q

What is the acetyl-CoA carboxylase reaction?

A

Bicarbonate is added to the lys side chain of biotin by biotin carboxylase
The side chain flips to the transcarboxylase side of the enzyme and adds an acetyl CoA to the carboxylic acid
Malonyl CoA is now made and leaves the lys side chain

Beginning of FA synthesis

18
Q

Fatty acid synthase

A

5 domain enzyme with an acyl carrier protein that carries out FA synthesis

19
Q

Briefly explain FA synthesis

A

ACP will bind to malonyl coa
Condensation of acetyl CoA to malonyl CoA, co2 leaves
Reduction of b keto group with NADPH + H+, NADP+ leaves
Dehydration of hydroxy group, new double bond, water leaves
Reduction of double bond with NADPH + H+

Repeat

20
Q

To make enough malonyl CoA to make palmitate, how many ATP are used?

A

7 ATP

7 Ac CoA + 7 co2 + 7 ATP –> 7 malonyl CoA + 7 adp + 7 Pi

21
Q

How much NADPH do you use when making palmitate?

A

14 NADPH

Ac CoA + 7 malonyl CoA + 14 NADPH + 14 H+ –> palmitate + 7 co2 + 8 CoA + 14 NADP+ + 6 h2o

22
Q

What is the coast of getting acetyl CoA outside of the matrix?

A

2 ATP

23
Q

What is the total cost of ATP in FA synthesis?

A

3 ATP per 2 c unit

24
Q

What are sources of NADPH?

A

PPP or the malic enzyme rxn

25
Q

How does acetyl CoA get outside the matrix?

A

Citrate synthase will convert it to citrate with OAA
Citrate leaves through transporter
Citrate lyase turns it into OAA using ATP and CoASH, leaving acetyl CoA
MDH converts OAA to malate using NADH
Malate can shuttle back into mito via transporter then to OAA OR
Malic enzyme converts malate into pyruvate making NADPH
Pyruvate gets transferred back into mitosis via transporter
Pyruvate carboxylase turns Pyruvate back into OAA using ATP

26
Q

Rate limiting step of FA synthesis

A

Acetyl CoA carboxylase rxn (make malonyl CoA)

27
Q

Regulation of ACC

A

Inhibited by palmitoyl CoA
Activated by citrate

Phosphorylation from glucagon and epi = inactive

28
Q

Fatty acyl CoA desaturase

A

Reduces bonds on FA bt c9 and c10

29
Q

How is FA converted into a fatty acylCoA?

A

Two step reaction with fatty acyl CoA synthetase adding AMP to a FA, then CoASH will kick off the AMP. In the process, make PPi that will be hydrolyzes into 2 Pi

30
Q

What tissues do b ox?

A

Heart and liver

31
Q

Advantage of fats over polysaccharides

A

Carry more energy, less water

Long term energy storage (hibernating bears)

32
Q

How are dietary fats absorbed?

A
  1. Bile salts emulsify fats in small intestine = mixed micelles
  2. Lipases degrade triacylglycerols in intestine
  3. Intestinal mucosa convert breakdown products back into triacylglycerols
  4. TAGs are incorporated into chylomicrons with cholesterol which move through the blood stream
  5. Lipoprotein lipase (part of apoCII) converts TAGs to FA and glycerol
  6. FA will enter cells and will go through b ox or stored

DMD 5242 (8 decks)

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