Brainscape's Knowledge GenomeTM

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


See full index

Biochemistry > Fatty acid metabolism > Flashcards

Fatty acid metabolism Flashcards

1
Q

what are the sources of lipids and fatty acids

A

diet
adipose storage
synthesis in tissue

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

what are the fates of lipids and fatty acids

A

energy substrates
precursors (acrachodinate acid)
structural elements(phospholipids)
signaling molecules(

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

what are bile salts and what do they do

A

emulsify dietary fats(lipids) in the small intestine and form mixed micelles

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

what do lipases do

A

degrade triaclyglycerols in to fatty acid

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

what do fatty acids get put back together in?

A

chylomicrons

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

what is a chylomicron?

A

it is an apolipoprotein that travels through the lymphatic system and blood stream to tissues that need them
carry triglycerides and fatty acids
made in enterocyte ER

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

what are apolipoproteins

A

lipid binding proteins
combine with lipids to form lipoproteins
diverse functions

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

what are the two ways that fatty acids are transported?

A

carried by serum albumin(free fatty acids)

and in lipoproteins (chylomicron)

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

what are the four types of lipoproteins

A

chylomicrons
very low density lipoprotein (VLDL)
low density lipoprotein (LDL)
high density lipoprotein (HDL)

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

where are the VLDLs produces?

A

liver

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

VLDL takes the fatty acid and cholesterol to the blood stream to target tissues. What are they called once they deliver the fatty acids or cholesterol?

A

LDL and go back to liver

also can deliver cholesterol to Macs

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

What is the exogenous pathway?

A

fats from our diet are packaged into chylomicrons and is sent to the liver for processing into VLDL

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

what is the endogenous pathway?

A

fats from the liver are put into VLDL and sent to target tissues (muscle, adipose, adrenal gland, gonads)

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

what do high density lipoproteins do?

A

take the excess cholesterol from the macs and the body back to the liver

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

what is the receptor on the LDL particle necessary for endocytosis?

A

apoB-100

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

When an LDL is internalized and broken down what can it be made into?

A

AAs, FAs and cholesterol

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

What is the triacylglycerol cycle?

A

under conditions of starvation or intense exercise fatty acids from adipose tissue and released into blood.
75% of released FAs are cycled back liver where they are make into triglycerides and transported via lipoproteins t target tissues

18
Q

fatty acid mobilization process

A

glucagon released from pancreas stimulates Gprotein receptor to activate adenylyl cylcase

  • this activates PKA(protein kinase A)
  • this phosphorylates perilipin
  • this causes it to dissociate and release CGI
  • CGI activates Adipose tryglyceride lipase (ATGL)
  • ATGL breaks down lipids into monoacylglycerol and diacylglycerol
  • PKA also phosphorylates hormone sensitive lipase
  • HSP breaks down the diacylglycerol into monoacylglycerols
  • Monoglyceride lipase removes the glycerol so the fatty acids can be released
19
Q

how are triglycerides broken down?

A

via lipases
broken down into glycerol and fatty acids
fatty acids form fatty acyl CoAs
glycerol is made into glyceraldehyde 3-phosphate

20
Q

how do the fatty acyl CoA get into the matrix of mitochondria?

A

via carnitine through an antiporter

**the CoA does NOT get transferred with the fatty acyl

21
Q

what are the three stages of fatty acid oxidation?

A
  1. beta oxidation
  2. citric acid cycle
  3. Oxidative phosphorylation
    * *remember this happens in the matrix of mitochondria
22
Q

how much ATP is produced by 1 16 carbon (palmiate) fatty acid?

A

108

23
Q

per 1 oxidation step in beta oxidation what are the products?

A 
1 Acetyl CoA (goes to CAC)
1 NADH ( goes to ETC)
1 FADH2 (goes to ETC)
24
Q

what enzyme feeds directly into the ETC?

A

acyl-CoA dehydrogenase, produces FADH2

25
Q

what are the two fates of acetyl CoA made in the liver?

A
  • goes into CAC for production of glucose through gluconeogenesis
  • can go form ketone bodies
26
Q

what are the three ketone bodies to know? why are they important?

A
  • Acetoacetate, Acetone(cannot be converted back into acetylCoA), beta-hydroxybutyrate
  • allow for recycling of CoA and also serve as energy for fuel for heart, muscle, kidney, and brain
27
Q

how do dietary proteins and carbs get turned into fatty acids and eventually triacylglycerols?

A
  • the acetyl CoA is carboxylated into malonyl CoA
  • acetyl CoA and malonyl CoA combine to start a acyl chain
  • fatty acid synthase adds malonyl CoA carbons to create palmitate
  • modified in ER (sterols, phospholipids)
28
Q

the citrate shuttle

A

transports acetyl CoA that is produced in the matrix into the cytoplasmic space where lipid synthesis occurs

29
Q

what does malic enzyme do and what does it produce?

A

takes malate to pyruvate

produces NADPH

30
Q

What enzyme carboxylates acetyl CoA into Malonyl-CoA

A

Acetyl-CoA carboxylase (ACC)

biotin is required(vit. B7)

31
Q

What are the two types of fatty acid synthase?

A
  • type I vertebrates and fungi (only makes plamitate) 16 carbon saturated fatty acids
  • type II in bacteria and plants
32
Q

Acyl carrier protein

A

fatty acid synthase(FAS) prosthetic group
holds malonyl group to FAS
needs pantothenic acid (vit. B5)

33
Q

lipid synthesis steps

A 
malonyl added to acetyl via condensation step
NADPH reduces 
dehydration
reduction again by NADPH
**adds two carbons at a time
34
Q

what essential fatty acid is produced by fatty acid synthase II

A

alpha linolenate

35
Q

what is the longest carbon chain that we can create as humans?

A

18 carbons

36
Q

how does Acetyl-CoA Carboxylase activity regulate fatty acid synthesis and breakdown

A

insulin activates ACC(phosphate dephosphoryates)
glucagon deactivates ACC(phosporylated by PKA)
**high levels of malonyl CoA deactivate fatty acid beta oxidation at the carnitine acyl transferase I enzyme

37
Q

fatty acid addition make phospholipids and triglycerides

what is the process?

A
  • glucose and glycerol and 2 acyl chains form phosphatidic acid
  • head groups and FAs are added to phosphatidic acid to make phospholipids
  • phosphatase can remove phosphate group and allow addition of another fatty acid to make a triglyceride
  • this occurs at the ER of the cell
38
Q

what does excess acetate lead to?

A

the formation of cholesterol, which is the basis for many sterols

39
Q

T/F cholesterol is involved in lipoprotein and hormone formation?

A

True, it is a necessary component of lipoprotein walls and for hormones

40
Q

what are foam cells?

A

macrophages that have taken up too many cholesterol molecules and build up in the arteries and form atherosclerosis.
*hence HDL is very important in removing the cholesterol from the macrophages

Biochemistry (14 decks)

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