Integration of metabolism

Question 1

What can the brain not use as a metabolic fuel source

Answer 1

fatty acids

Question 2

where is the body’s main carb store

Answer 2

liver

Question 3

what is glucose stored as

Answer 3

glycogen

Question 4

what method of respiration does skeletal muscle do in light contraction

Answer 4

ox phos

Question 5

why can’t skeletal muscle do ox phos in vigorous exercise

Answer 5

ATP consummation faster than supplied, limited by O2 and glucose/fatty acid

Question 6

what does muscle do in vigorous exercise

Answer 6

break down glycogen

Question 7

what happens in anaerobic respiration

Answer 7

pyruvate to lactate which enters liver

Question 8

What fuel can the brain use

Answer 8

ketone bodies and glucose

Question 9

hypoglycaemia causes…

Answer 9

fainting and coma

Question 10

hyperglycaemia causes..

Answer 10

irreversible change

Question 11

How is heart designed for aerobic respiration

Answer 11

many mt

Question 12

what fuel does the heart use

Answer 12

TCA substrates: fatty acid and ketone bodies

Question 13

loss of O2 to heart causes

Answer 13

MI

Question 14

metabolic processes that take place in liver

Answer 14

glycolysis, gluconeogenesis, transamination, lipoprotein metabolism

Question 15

how much of body’s metabolic rate does liver do

Answer 15

20%

Question 16

what happens to excess glucose - 6- phosphate

Answer 16

turns to glycogen - liver and muscle

Question 17

what happens to aexcees acetyl CoA

Answer 17

turns to fatty acid

Question 18

in fasting what happens to acetyl CoA

Answer 18

ketone body production

Question 19

how can pyruvate and TCA intermediates make AA

Answer 19

backbones form nucleotides

Question 20

how does glucose-6-phosphate contribute to the production of NADPH

Answer 20

make nucleotides via pentose phosphate pathway

Question 21

at what glucose conc will the body become hypoglycaemic

Answer 21

3mM

Question 22

How does the body avoid hypoglycaemia

Answer 22

breakdown glycogen, release fatty acids, convert acetyl CoA to ketone bodies

Question 23

how long does it take for glycogen stores to be depleted

Answer 23

12-18 hours

Question 24

purpose of gluconeogenesis

Answer 24

produce glucose from non-carb sources (pyruvate)

Question 25

when is gluconeogenesis important

Answer 25

starvation

Question 26

why is gluconeogenesis not a reversal of glycolysis

Answer 26

different enzymes - irreversible reactions

Question 27

where does gluconeogenesis occur

Answer 27

liver

Question 28

what does gluconeogenesis need and why

Answer 28

ATP source, make reactions energetically favourable

Question 29

which precursors enter gluconeogenesis

Answer 29

lactate, aa, glycerol

Question 30

How can lactate regenerate pyruvate

Answer 30

Cori cycle - LDH

Question 31

Where do AA come from for gluconeogenesis

Answer 31

diet/breakdown of muscle

Question 32

What does triglyceride hydrolysis do?

Answer 32

yield fatty acid and glycerol - glycerol backbone generate DHAP

Question 33

which enzymes catalyse the irreversible reactions in glycolysis

Answer 33

hexokinase, phosphofructokinase, pyruvate kinase

Question 34

enzymes in gluconeogenesis

Answer 34

``` pyruvate carboxylase (p - oxyloacetate) phospoenolpyruvate carboxykinase (o-phospoenolpyruvate) Fructose 1,6 bisphosphatase(fructose 1,6 bp - f 6 p) ``` glucose 6 phophotase (g-6-p - glucose)

Question 35

where does pyruvate decarboxylase act

Answer 35

mt

Question 36

waste product of deamination

Answer 36

urea

Question 37

What are the glycogenic AA skeletons

Answer 37

Pyruvate, alpha - ketoglutarate, succinyl CoA, fumarate, oxaloacetate

Question 38

what are the ketogenic aa skeletons

Answer 38

acetyl CoA, acetoacetyl CoA

Question 39

What are glucogenic AA

Answer 39

skeleton give ris to glucose by gluconeogenesis

Question 40

what are ketogenic AA

Answer 40

used to synthesis fatty acid and ketone bodies

Question 41

How is the increased demand for glucose met?

Answer 41

increase in the number of glucose transporters on membrane of muscle cells

Question 42

what does adrenaline do

Answer 42

increase glycolysis and gluconeogenesis rate, increase release of fatty acids

Question 43

why is pyruvate converted to lactate in anaerobic respiration

Answer 43

restore NAD+ levels

Question 44

Which reactions are the best to control to control metabolic pathways

Answer 44

irreversible steps

Question 45

How can you control metabolic pathways

Answer 45

product inhibition, signalling molecules

Question 46

Km hexokinase 1 (muscle)

Answer 46

o.1mM

Question 47

effect of low Km

Answer 47

active at low glucose conc

Question 48

What inhibits hexokinase 1

Answer 48

glucose-6-phosphate

Question 49

Km of hexokinase 1V (liver)

Answer 49

4mM

Question 50

effect of high Km

Answer 50

less sensitive to blood glucose conc

Question 51

sensitivity of hexokinase 1V to glucose-6-phosphate

Answer 51

low

Question 52

where is glucose-6-phosphotase found

Answer 52

liver

Question 53

What do glucocorticoids do

Answer 53

increase synthesis of met enzymes concerned with glucose availability

Question 54

where are adrenaline and glucocorticoids secreted from

Answer 54

adrenal glands

Question 55

insulin effects:

Answer 55

increased glucose uptake, liver and muscle, triglyceride synthesis, increased use of metabolic intermediates (stimulatory effect on synthesis and growth)

Question 56

to stop glucose levels dropping...

Answer 56

glucagon secreted, gluconeogenesis, fatty acid breakdown as a substrate for ATP production.

Question 57

what happens after prolonged fasting

Answer 57

``` glucagon/insulin ratio increases hydolysise fatty acids TCA intemediates break down protein break down ketone bodies from fatty acids and aa ```

Question 58

overall effect of diabetes

Answer 58

metabolism controlled as if in starvation

Question 59

what causes acidosis

Answer 59

increase in ketone bodies

Question 60

How does diabetes cause cardiovascular problems

Answer 60

increased fatty acids and lipoprotein levels

Question 61

effect of glucagon

Answer 61

stimulate gluconeogenesis

Question 62

risk of relative excess of glucagon compared to insulin

Answer 62

high heptic output of glucose - hyperglycaemia