Brainscape's Knowledge GenomeTM

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


See full index

BIO1332 - Biochemistry > Fatty Acid Metabolism > Flashcards

Fatty Acid Metabolism Flashcards

1
Q

What is the function of fatty acids?

A
  • Energy storage and production
  • Structural components of membranes
  • Some hormones are derived from fatty acids
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is a saturated fatty acid?

A

no double bonds

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

What is an unsaturated fatty acids?

A

One or more double bonds

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

Do fatty acids normally have an even or odd number of C atoms?

A

Even

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

What is aliphatic?

A

Composed of hydrogen and carbons

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

What are fatty acids made of?

A

Aliphatic side chain

Acidic head

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

What is an acidic head?

A

carboxylic acid

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

Are saturated fatty acids better than unsaturated fatty acids?

A

No, unsaturated fatty acids are better

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

What are lipids?

A

A mixture of fatty acids and glycerol

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

What does a triacylglycerol consist of?

A
  • 3 fatty acids
  • On glycerol

Linked by ester bonds

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

What are esters?

A

Linkages formed between a carboxylic acid (-COOH) and alcohol –OH) groups by loss of water

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

Are lipids hydrophilic or hydrophobic?

A

Hydrophobic

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

Are lipids easy or hard to transport?

A

Hard

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

What can triacylglycerol be?

A

An energy source

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

What can all tissues except the brain do?

A

Oxidise fatty acids derived from triacylglycerol to produce energy

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

When is triacylglycerol used?

A

When glucose supplies are low

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

triacylglycerol + 3H2O =

A

Glycerol and 3 fatty acids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

How is lipase activated?

A

Normally by glucagon

19
Q

How are fatty acids transported?

A

In the blood complexed with serum albumin

20
Q

What are the three step process of oxidation of fatty acids?

A

Step 1: Free fatty acids in the cytosol are activated forming fatty acyl-CoA

Step 2: Fatty acyl-CoA uptake into mitochondria.

Step 3: b-oxidation pathway in mitochondrial matrix

21
Q

What happens in the first stage of oxidation of fatty acids?

A
  • Oxygen from fatty acid attacks phosphorus
  • Releases inorganic pyrophosphate
  • AMP and fatty acid attached (bonded together by ester bond)
  • Co-A reacts with acyladenylate mixed anhydride where AMP is rejected and fatty acyl-co A is formed
22
Q

What happens in the second stage of oxidation of fatty acids?

A
  • Fatty acid oxidised by mitochondria (in mammals)
  • The inner mitochondrial membrane is not permeable to fatty acids or fatty acyl CoA
  • So the carnitine shuttle is used to transport fatty acyl CoA from the cytoplasm to the mitochondrial matrix.
23
Q

What happens in the third stage of oxidation of fatty acids?

A
  • Beta (C3) carbon oxidised
  • H removed from a and B carbons by acyl CoA dehydrogenase (contains FAD cofactor)
  • Electrons delivered to coenzyme Q in electron transport chain
  • Hydration of double bond (addition of water). To produce hydroxyacyl-CoA
  • C-OH oxidised to C=O
  • NADH formed is oxidised by electron transport chain to produce ATP
  • CoASH attacks b carbon to produce acetyl CoA and a fatty acyl CoA which is now 2 C atoms shorter.
  • Acetyl CoA oxidised by citric acid cycle.
24
Q

What is important about step 3 of oxidation of fatty acids?

A

Even chain fatty acids this process repeats until all of the molecule is converted into acetyl CoA

25
Q

What is the net yield of ATP in oxidation of fatty acids?

A

106 ATP

26
Q

How many ATPs are generated per acetyl CoA?

A

10

27
Q

What does the glyoxylate cycle allow?

A

Plants, fungi and bacteria to make sugar from fatty acids

28
Q

What can plants, fungi and bacteria that animals cant?

A

Convert acetyl CoA

29
Q

Where does glyoxylate cycle operate?

A

Glyoxysomes

30
Q

What is the overall reaction of glyxoylate cycle?

A

2 Acetyl CoA —-> malate —-> oxaloacetate

31
Q

What can mammals create glucose from?

A

Propionyle CoA

32
Q

What do odd chain length of fatty acids yield?

A

Acetyl CoA and propionyl CoA

33
Q

Where does B oxidation occur?

A

in the mitochondrion

34
Q

Where does biosynthesis take place?

A

Cytoplasm

35
Q

How are B oxidation and biosynthesis similar?

A

Same intermediates

36
Q

How are B oxidation and biosynthesis different?

A

-Occurs in the cytoplasm using a different carrier (acyl carrier protein (ACP) instead of CoA), different cofactors (NADP+ instead of FAD and NAD+) and a different C2 donor/product (malonyl CoA instead of acetyl CoA).

37
Q

What does the pirate shuttle deliver?

A

Acetyl CoA from the mitochondria to the cytoplasm.

38
Q

Describe the process of fatty acid synthesis:

A
  • Energy to form C-C bonds is supplied indirectly by synthesizing malonyl CoA from acetyl CoA using ATP and CO2 (catalyzed by Acetyl CoA carboxylase )
  • The C=O group on C3 (b carbon) is reduced to C-OH by NADPH.
  • Dehydration (removal of water) – generates a double bond between the a and b carbons (C2 and C3).
  • Reduction of double bond to single bond
  • fatty acyl-ACP, now 2C longer, can re-enter the process OR the process is stopped by removing ACP (using fatty acyl-ACP thioesterase)
39
Q

What is fatty acid synthase?

A
  • single multifunctional enzyme
  • Exists as dimers
  • Arrangement eases movement of fatty acyl chain through the complex process
  • Anchored to ACP
40
Q

Is Acetyl CoA carboxylase is tightly regulated?

A

Yes

41
Q

How is Acetyl CoA carboxylase is tightly regulated?

A
  • inhibited by phosphorylation

- controlled by glucagon and adrenaline.

42
Q

How does insulin signalling favour fatty acid synthesis?

A

Activating a phosphatase that dephosphorylates acetyl CoA carboxylase

43
Q

Finish the sentence:

Fatty acid synthesis and breakdown are …

A

reciprocally regulated

44
Q

What does glucagon promote in fatty acids?

A

Release of fatty acids from adipocytes

BIO1332 - Biochemistry (19 decks)

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