Exam - Metabolic Integration

Question 1

what must metabolic integration maintain

Answer 1

blood glucose between 60-100mg/dL

Question 2

what happens if blood glucose is < 60 mg/dL

Answer 2

development of a coma and can be fatal

Question 3

why is blood glucose required by red blood cells

Answer 3

as an energy substrate because they have no mitochondria

Question 4

what is blood glucose required by

Answer 4

red blood cells
central nervous system
to maintain an active krebs cycle

Question 5

in the fed state, what is the predominant source of blood glucose

Answer 5

dietary CHO
dietary protein

Question 6

in the post-absorptive state, what is the predominant source of blood glucose

Answer 6

glycogen from liver (glycogenolysis)

Question 7

in the fasting state, what is the predominant source of blood glucose

Answer 7

gluconeogenesis from protein catabolism

Question 8

in the starvation state, what is the predominant source of blood glucose

Answer 8

gluconeogenesis from glycerol produced by TAG breakdown
some protein catabolism

Question 9

4 main hormones for metabolism regulation

Answer 9

insulin
glucagon
corticosteroids (cortisol)
catecholamines (epinephrine)

Question 10

what is the nature of insulin

Answer 10

anabolic

Question 11

what is the nature of glucogon

Answer 11

catabolic

Question 12

what is the nature of corticosteroids

Answer 12

catabolic

Question 13

what is the nature of catecholamines

Answer 13

catabolic

Question 14

what is insulin produced by

Answer 14

B-cells in pancreas

Question 15

what is glucagon produced by

Answer 15

a-cells in pancreas

Question 16

what is corticosteroids produced by

Answer 16

adrenal cortex

Question 17

what are catecholamines produced by

Answer 17

adrenal medulla

Question 18

what are the main effects of insulin

Answer 18

increases glucose and AA uptake in muscle and liver
increases glycogen and protein synthesis in muscle and liver
increases TAG synthesis and storage in adipose

Question 19

what are the main effects of glucagon

Answer 19

increased breakdown of glycogen, protein and fat
increased gluconeogenesis from AAs and glycerol

Question 20

what are the main effects of corticosteroids

Answer 20

increases protein catabolism
increases gluconeogenesis from AAs

Question 21

what are the main effects of catecholamines

Answer 21

increases glycogenolysis and lipolysis

Question 22

what are T3 (T4) hormones

Answer 22

tyrosine-based hormones produced by thyroid that affect metabolic rate

Question 23

what does the brain have a high requirement for

Answer 23

oxidative metabolism to suppor continuous electrical activity

Question 24

what does the brain depend on

Answer 24

glucose

Question 25

how many g of glucose is required by the brain per day

Answer 25

100-120

Question 26

why does the brain depend on glucose as opposed to other energy sources

Answer 26

fatty acids cannot cross the blood-brain barrier enough to provide sufficient energy

Question 27

how much glucose does the liver produce during an overnight fast

Answer 27

2mg/min/kg body weight

Question 28

how much of the glucose produced by liver in overnight fast is consumed by the brain

Answer 28

half

Question 29

what is the main purpose of the liver

Answer 29

regulating

Question 30

what does the liver regulate

Answer 30

blood glucose levels

Question 31

what is the liver a major site for

Answer 31

fatty acid B-oxidation

Question 32

what is the only tissue to produce ketone bodies

Answer 32

liver

Question 33

what kind of energy requirements does adipose tissue have

Answer 33

low - not a lot of oxidative fuel consumption

Question 34

when is glucose used in adipose tissue

Answer 34

for de novo lipogenesis TAG synthesis provide energy for fatty acid uptake

Question 35

what does adipose tissue release into circulation

Answer 35

non-esterified fatty acids from lipolysis

Question 36

can non-esterified fatty acids be metabolic fuel

Answer 36

yes - depending on circumstances

Question 37

what are non-esterified fatty acids the same as

Answer 37

free fatty acids

Question 38

what percentage of body weight does skeletal muscle represent

Answer 38

40%

Question 39

what are the main regulators for muscle fuel consumption

Answer 39

nutritional status and exercise

Question 40

2 fibres in skeletal muscle

Answer 40

slow twitch fast twitch

Question 41

when are slow twitch muscle fibres used

Answer 41

long duration activities - slow contraction

Question 42

what is the predominant source of energy for slow twitch skeletal muscle fibres

Answer 42

fatty acids

Question 43

when are fast twitch muscle fibres used

Answer 43

short duration activities - fast contraction

Question 44

what provides energy for fast twitch muscle fibres

Answer 44

local glycogen stores

Question 45

what type of glucose is used quickly

Answer 45

precious

Question 46

how long are glycogen stores sufficient for

Answer 46

24 hours

Question 47

when does protein breakdown occur

Answer 47

initially - releases glycogenic amino acids which slows down to preserve protein function

Question 48

why does fatty acid breakdown occur

Answer 48

to spare protein - eventually used to make ketone bodies

Question 49

how long does the fed state last

Answer 49

0-2 hours after eating

Question 50

what is the only hormone in the body that lowers blood sugar

Answer 50

insulin

Question 51

what are the percentages of urea and NH4+ during the fed state

Answer 51

90% urea 10% NH4+

Question 52

what is promoted in liver and muscle during fed state

Answer 52

glucose uptake and glycogen formation

Question 53

what is the primary hormone in the fed state

Answer 53

insulin

Question 54

what occurs in adipose tissue in the fed state

Answer 54

TAG synthesis - long term energy storage

Question 55

what occurs in the liver during the fed state

Answer 55

clears blood glucose (for glycogen or TAG production) urea cycle active

Question 56

what occurs in muscle during the fed state

Answer 56

protein synthesis (BCAA) replenish glycogen reserve

Question 57

what is the primary hormone in the post-absorptive state

Answer 57

glucagon

Question 58

what occurs in the adipose tissue in the post-absorptive state

Answer 58

nothing

Question 59

what occurs in the liver in the post-absorptive state

Answer 59

glycogen breakdown urea cycle active

Question 60

what occurs in the muscle in the post-absorptive state

Answer 60

glycogen breakdown protein catabolism

Question 61

when is the post absorptive state

Answer 61

3-18 hour after eating

Question 62

urea vs NH4+ during post absorptive state

Answer 62

still mainly urea

Question 63

what is the primary hormones in the fasted state

Answer 63

corticosteroids and glucagon

Question 64

what occurs in the adipose tissue during the fasted state

Answer 64

TAG start to become lipolysed (releasing free fatty acids and glycerol)

Question 65

what occurs in the liver during the fasted state

Answer 65

produces and secretes glucose via gluconeogenesis; urea cycle activity reduced

Question 66

what occurs in the muscle during the fasted state

Answer 66

protein catabolism

Question 67

urea vs NH4+ in fasted state

Answer 67

decrease of urea and increase of NH4+

Question 68

when does the fasted state occur

Answer 68

18-48 hours with no food intake

Question 69

what are the primary hormones during starvation

Answer 69

catecholamines and glucagon

Question 70

what occurs in the adipose tissue during starvation

Answer 70

TAG lipolysis

Question 71

what occurs in the liver during starvation

Answer 71

ketone production glycerol backbone of TAG used to make glucose urea cycle is minimally active

Question 72

what occurs in the muscle during starvation

Answer 72

muscle protects its protein still some protein catabolism happening to support blood glucose but not a lot

Question 73

how long does it take for it to be considered starvation

Answer 73

about 2 weeks

Question 74

urea vs NH4+ during starvation

Answer 74

10% urea 90% NH4+