Lecture 6 - CHO metabolism during exercise Flashcards Preview

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Flashcards in Lecture 6 - CHO metabolism during exercise Deck (23):
1

liver glucose output is subject to _____, _____ controls

multiple, redundant

2

Training reduces reliance on ___ as a fuel source

CHO

3

What converts Pyruvate to Lactate?

lactate dehydrogenase

4

Early on in exercise the rate of glycogen breakdown is..

most rapid

5


When glycogen runs out, this is associated with

exhaustion - assoicated with fatigue

6

What are the factors that regulate glycogen breakdown?

Ca2+, Pi - the important local stimuli, will activate glycogen phosphorylase

Adrenaline - activates b receptors, stimulates glycogen breakdown

Muscle [glycogen] - offset slightly, but still advantageous to load muscle with glycogen = more of it

FFA - reciprocally increases/decreases

Temperature - direct effect of muscle temp - speeds up rate of reaction. Also supplies more adrenaline

7

Trained individuals will reduce the amount of glycogen breakdown at a certain intensity because

there is less adrenaline

better regulation of your ATP turnover so the increase in Pi is not as high

8

What are the determinants of glucose uptake into the muscle?

diffusion gradient

concentration in the capillaries

amount of GLUT 4 at the membrane

metabolism - hexokinase activity


9

over time if the glucose concentration falls..

the glucose uptake is effected

10

Glycogen in the muscle will reduce...

the glucose uptake (leaves it for the CNS)

11

Adrenaline doesn't necessarily influence glucose uptake, but does effect....

glycogen breakdown

12

Liver glucose output is closely matched with...

muscle glucose uptake - but elongated exercise period cause liver glucose output to fall (there is a finite capacity)

13

Is there glyocogen in the liver?

yes - broken down by _______

14

Gluconeogenesis is mainly done in the ...

liver, but also kidney and muscle

15

an hour of exercise will drop liver glycogen levels by.

50%

16

Glucagon will stimulate the enzymes involved in...

gluconeogenesis

17

What are the factors which regulate liver glucose output during exercise?

feedforward and feedback mechanisms:

insulin (downreg.) and glucagon (from pancreas)

Adrenaline

Sympathetic nerves

Liver [glycogen] - if there's more of it, more will be broken down (same as in muscle)

Blood [glucose] - when injested the endogenous glucose production is reduced - its already there from the GIT

18

The liver is supplies by blood circulation from the...

Gut and pancreas

19

After training there's a reduction in _____ uptake and oxidation

glucose uptake and oxidation

20

PDH activity goes down over time during exercise causing ..

a reduction of CHO oxidation - PDH a the rate limiting enzyme

21

Liver glucose output is closely matched with Glucose ____

uptake

22

What can be converted to glucose in the liver

AA, glycerol, Pyruvate, lactate

process called gluconeogenesis

23

Does the muscle perform gluconeogenesis?

only a very small amount - during recovery

The kidney does a little but as well in the fasted state