D2 post absorptive state

Question 1

what are the 2 major essential polyunsaturated fatty acids

Answer 1

linoleic acid [C18:2]
linolenic acid [C18:3]

Question 2

what lipid soluble vitamins are only present in dietary fat and require fat for absorption

Answer 2

A, D, E, and K

Question 3

3 types of fat in our diet and body

Answer 3

-triacylglycerols (triglycerides)
-phospholipids
-cholesterol

Question 4

basic structure of triacylglyerols

Answer 4

3 fatty acids attached to a glycerol

Question 5

basic structure of phospholipids

Answer 5

2 fatty acids and a head group attached to glycerol

Question 6

basic structure of cholesterol

Answer 6

4 ring hydrocarbon

Question 7

what does saturated and unsaturated mean

Answer 7

saturated= no double bonds
unsaturation= 1+ double bonds

Question 8

what are the 4 common head groups of phospholipids
(glycerophospholipids)

Answer 8

-phosphocholine
-phosphoethanolamine
-phosphoserine
-phosphoinositol

Question 9

what is digestion of fat carried out by

Answer 9

lipases

Question 10

what carries out digestion of fat in the mouth

Answer 10

lingual lipase

Question 11

what carries out digestion of fat in the stomach

Answer 11

gastric lipase

Question 12

what carries out digestion of fat in the intestine

Answer 12

pancreatic lipase,
phospholipase
(absorption of fatty acids, glycerol, fats)

Question 13

properties of lipids (FA)

Answer 13

hydrophobic
insoluble in aq environments

Question 14

what transports FA around the body

Answer 14

lipoproteins

Question 15

name of fatty acid oxidation

Answer 15

b-oxidation

Question 16

what are the 5 major step names in the oxidation of fatty acids in the mitochondria

Answer 16

1. activation
   1a transport
2. oxidation
3. hydration
4. oxidation
5. thiolysis

Question 17

activation

Answer 17

to form a thioester bond with CoA

Question 18

transport

Answer 18

into mitochondia

Question 19

oxidation 1

Answer 19

2 H removed - double bond C=C

Question 20

hydration

Answer 20

H2O added across double bond C=C

Question 21

oxidation 2

Answer 21

C-OH converted to C=O

Question 22

thiolysis

Answer 22

acetyl-CoA cleaved from activated end

Question 23

what does the thiol group of coenzyme A form

Answer 23

a high energy thioester bond with the carboxylic acid group of the fatty acid

Question 24

what is the energy source in the activation of fatty acids by CoA

Answer 24

driven by ATP and subsequent hydrolysis of pyrophosphate
(2 high energy bonds)

Question 25

where are fatty acids transported to

Answer 25

mitochondria

Question 26

what does the transport of activated fatty acids into mitochondria use as a carrier

Answer 26

carnitine

Question 27

what is carnitine

Answer 27

an acyl-carrier that transports the fatty acyl chains

Question 28

how much ATP does each round of b-oxidation produce

Answer 28

14 ATP (2.5 NADH 1.5 FADH2 10 acetyl CoA)

Question 29

how many rounds of oxidation does palmitate need

Answer 29

7

Question 30

what is the total yield of ATP from complete breakdown of fatty acids

Answer 30

106 (14x7)+10=108 but 2 used to activate the fatty acid

Question 31

what enzyme is required for the degradation of unsaturated fatty acids for one c=c double bond

Answer 31

cis-D 3-Enoyl CoA isomerase

Question 32

what enzymes are required for the degradation of unsaturated fatty acids for two C=C double bonds

Answer 32

cis-D3-Enoyl CoA isomerase 2,4-Dienoyl CoA reductase

Question 33

when can acetyl CoA only enter the TCA

Answer 33

if carbohydrate and fat metabolism are balanced

Question 34

what occurs if fat metabolism predominates and why

Answer 34

shortage of oxaloacetate because its used for gluconeogenesis (to make glucose) and hence an excess of acetyl CoA

Question 35

if fat predominates what is acetyl-CoA converted to

Answer 35

ketone bodies

Question 36

what do odd chain fatty acids yield at the end of the degradation

Answer 36

propionyl-CoA (3C)

Question 37

what is propionyl-CoA converted into

Answer 37

succinyl-CoA by addition of bicarbonate (HCO3) which then enters TCA cycle

Question 38

what 2 things are required for the degradation of odd chain fatty acids

Answer 38

ATP and vitB12

Question 39

what is the daily glucose requirement of the brain of a typical human being

Answer 39

120g

Question 40

how much glucose needed daily by the whole body

Answer 40

160g

Question 41

how much glucose is found in body fluids

Answer 41

20g

Question 42

how much glucose is stored in glycogen

Answer 42

190g

Question 43

when is gluconeogenesis esp important

Answer 43

during period of starvation

Question 44

what is gluconeogenesis and where does it mainly occur

Answer 44

conversion of pyruvate into glucose in liver

Question 45

major carbohydrate precursors are

Answer 45

lactate propionate aa glycerol

Question 46

where does lactate come from

Answer 46

rate of glycolysis exceeds the rate of oxidative metabolism

Question 47

where does aa come from

Answer 47

breakdown of proteins

Question 48

where does propionate and glycerol come from

Answer 48

hydrolysis of triacylglycerols

Question 49

in what body parts are glucose 6 phosphate present in

Answer 49

liver and kidney

Question 50

where in cells is glucose 6 phosphate located

Answer 50

membrane of ER

Question 51

how many proteins are needed to transform glucose 6 phosphate into glucose

Answer 51

5

Question 52

3 steps of converting glucose 6 phosphate to glucose

Answer 52

-G6P transported into ER -G6P hydrolysed -glucose and Pi transported into cytosol

Question 53

what are the cofactors to fructose 1,6-biphosphatase

Answer 53

Mg2+ Mn2+ and/or Zn2+

Question 54

what activates fructose 1,6-biphosphatase

Answer 54

citrate

Question 55

can pyruvate be converted to phosphoenolpyruvate (PEP) by pyruvate kinase

Answer 55

no because the reaction is irreversible under intracellular conditions

Question 56

how is the reversal of the reaction achieved (pyruvate conversion)

Answer 56

coupling of 2 rxns requiring ATP and GTP

Question 57

where is pyruvate carboxylase localised

Answer 57

mitochondrium

Question 58

what does pyruvate carboxylase carry as a prosthetic group

Answer 58

biotin

Question 59

what does biotin function as

Answer 59

carrier for activated CO2

Question 60

where is the activated carboxyl group transferred to to form what

Answer 60

pyruvate to form oxaloacetate