Biochemistry- Lipids

Question 1

What is the action of lipase?

Answer 1

breaks down ester bonds

Question 2

What constitutes a triglyceride?

Answer 2

3 fatty acids attached to a glycerol backbone

Question 3

Lecithin or phosphatidylcholine is found in what substance?

Answer 3

phospholipids

Question 4

what mineral is important in cell membranes?

Answer 4

phosphorous

Question 5

What does saturated refer to?

Answer 5

all carbons of a fatty acid are saturated with hydrogens (no double bonds)

Question 6

double bonds are seen in what kind of fatty acid?

Answer 6

unsaturated

Question 7

how are lipids transported in the blood?

Answer 7

via lipoproteins

Question 8

how many carbons are in a short chain fatty acid?

Answer 8

6-10

Question 9

how many carbons are in a medium chain fatty acid?

Answer 9

12-14

Question 10

how many carbons are in a long chain fatty acid?

Answer 10

16-20

Question 11

Animal fat is a good source of what type of fatty acid?

Answer 11

saturated

Question 12

oleic, linoleic and alpha linolenic acids are examples of what type of fatty acid?

Answer 12

unsaturated

Question 13

hydrogenation of fatty acids produces what?

Answer 13

trans fatty acids

Question 14

What are 2 effects of trans fatty acids on the body?

Answer 14

1. interfere with essential fatty acid metabolism

2. may be athergenic

Question 15

what substance emulsifies fatty acid?

Answer 15

bile

Question 16

How do triglycerides cross the intestinal membrane?

Answer 16

drop 2 fatty acids, cross the membrane and reform intracellularly

Question 17

Ho do tricglycerides travel in general circulation?

Answer 17

via chylomicrons in the lymphatics and blood

Question 18

Where does beta oxidation take place?

Answer 18

in the mitochondria of all cells

Question 19

where does fatty acid synthesis take place?

Answer 19

in the cytosol of all cells

Question 20

what is the activated form of a fatty acid?

Answer 20

Acyl-CoA

Question 21

How is Acyl-CoA transported into the mitochondria?

Answer 21

carnitine shuttle- (carnitine palitoyl transferase I, II and the carnitine acyl transferase enzymes)

Question 22

What coenzyme is needed in the activation of fatty acids into acyl-CoA?

Answer 22

B5 pantothenic acid (acyl CoA synthase)

Question 23

What coenzymes are needed in the beta-oxidation pathway?

Answer 23

B2 FAD

B3 NAD

Question 24

What is the rate limiting enzyme in fatty acid synthesis?

Answer 24

Acetyl-CoA carboxylase

Question 25

What is the intermediate substrate for fatty acid synthesis?

Answer 25

Acetyl-CoA--> AcetoacetylCoA--> Acyl CoA --> FFA

Question 26

Acetyl CoA carboxylase acts on Acetyl-CoA to form what?

Answer 26

Malonyl CoA

Question 27

What coenzyme is important for the production of malonylCoA from acetyl CoA?

Answer 27

Biotin

Question 28

What reducing agent is used in fatty acid synthesis?

Answer 28

NADPH

Question 29

How does acetyl CoA get out into the cytoplasm for fatty acid synthesis?

Answer 29

citrate leaves the mitochondrion and the action of citrate lyase forms acetyl CoA and oxaloacetate

Question 30

What hormone promotes fatty acid synthesis?

Answer 30

insulin

Question 31

What is the end product of de novo fatty acid synthesis?

Answer 31

palmitate

Question 32

What substance is the activated end product of lipogenesis and will cause feedback inhibition on actyl-CoA carboxylase?

Answer 32

Palmitoyl-CoA

Question 33

What 3 tissues undergo lipogenesis?

Answer 33

liver, skeletal muscle, cardiac muscle

Question 34

where does chain elongation take place?

Answer 34

in the mitochondrion and smooth ER

Question 35

which tissues undergo de novo fatty acid synthesis?

Answer 35

liver and adipose tissue

Question 36

Where does de novo synthesis take place?

Answer 36

in the cytoplasm

Question 37

What are the 3 ketone bodies?

Answer 37

Acetoacetate, acetone, betak hydroxybutyrate

Question 38

Keton production takes place when which substance is low?

Answer 38

oxaloacetate

Question 39

in what tissue does ketone synthesis take place?

Answer 39

liver

Question 40

where in the cell does ketone synthesis take place?

Answer 40

mitochondrial matrix

Question 41

What is the fate of acetone?

Answer 41

usually exhaled

Question 42

What is the fate of 3-hydroxybutyrate?

Answer 42

gets oxidized into acetoacetate

Question 43

What 2 tissues can use acetoacetate?

Answer 43

brain, skeletal muscle

Question 44

What are the 3 essential fatty acids?

Answer 44

linoleic acid alpha-linolenic acid arachidonic acid

Question 45

What is a good source of linoleic acid?

Answer 45

vegetables, nuts, seeds

Question 46

What is a good source of alpha-linolenic acid?

Answer 46

flaxseeds

Question 47

what is the name of the enzyme that converts linoleum and alpha linolenic acid into their metabolites?

Answer 47

delta-6 desaturase

Question 48

Which essential fatty acid is omega-3?

Answer 48

alpha-linolenic

Question 49

Which essential fatty acid is omega-6?

Answer 49

linoleic acid

Question 50

Which EFA is a precursor for series 2 eicosanoids?

Answer 50

arachadonic acid

Question 51

Which EFA is a precursor for series 1 eicosanoids?

Answer 51

linoleic acid

Question 52

Which EFA is a precursor for series 3 eicosanoids?

Answer 52

alpha-linolenic acid

Question 53

Linoleum acid turns into what fatty acid?

Answer 53

gamma linolenic acid (GLA)

Question 54

What are some good sources of GLA?

Answer 54

Evening primrose oil, borage oil, black currant oil

Question 55

What does alpha-linolenic acid become?

Answer 55

Eicosapentaeinoic acid (EPA)

Question 56

What is a good source for eicosapentaeinoic acid? (alpha-linolenic acid)

Answer 56

cold water fish oils (EPA)

Question 57

What is the name of the enzyme that releases arachidonic acid from cell membranes?

Answer 57

phospholipase A2

Question 58

What is the name of the enzyme that converts arachidonic acid into prostaglandins?

Answer 58

cyclooxygenase (also forms thromboxanes), is susceptible to NSAID inhibition

Question 59

What is the name of the enzyme that forms leukotrienes from arachidonic acid?

Answer 59

lipoxygenase

Question 60

What products inhibit phospholipase A2?

Answer 60

corticosteroids

Question 61

What products inhibit cyclooxyrgenase activity?

Answer 61

Aspirin (NSAIDs)

Question 62

What hormone promotes the conversion of carbohydrates into triglycerides?

Answer 62

Insulin

Question 63

What enzyme causes the release of fatty acids from triglycerides?

Answer 63

hormone sensitive lipase

Question 64

What are free fatty acids usually bound to?

Answer 64

albumin

Question 65

What hormone inhibits that action of hormone sensitive lipase?

Answer 65

insulin

Question 66

What promotes hormone sensitive lipase?

Answer 66

growth hormone, glucagon, epinephrine

Question 67

Esterification is used in the formation of TCGs from what two substances?

Answer 67

Acyl CoA and Glucose-6-Phosphate

Question 68

Free fatty acids are mobilized from what cell?

Answer 68

adipocyte

Question 69

What apoprotein marks HDL for hepatic uptake?

Answer 69

Apo A1, (and Apo E, but that is primarily for chylomicrons)

Question 70

What carries dietary fat in the body?

Answer 70

Chylomicrons

Question 71

Which tissues synthesize chylomicrons?

Answer 71

mucosal cells of the small intestine

Question 72

Apoprotein A is found on what lipoprotein?

Answer 72

HDL

Question 73

Which lipoprotein functions to carry TCGs from the liver to extra hepatic tissues?

Answer 73

VLDL

Question 74

Which lipoprotein functions to carry cholesterol from the liver to extra hepatic tissues?

Answer 74

LDL

Question 75

Which apoprotein allows for uptake of cholesterol by cells?

Answer 75

Apo B

Question 76

Chyloremnants are formed from the action of which enzyme?

Answer 76

Lecithin acyl transferase

Question 77

What apoprotein activates lecithin acyl transferase?

Answer 77

Apo A (HDL)

Question 78

Which transfer protein facilitates transfer of cholesterol from LDL and VDL to HDL?

Answer 78

cholesterol transfer protein