regulation of glucose uptake, HK and PFK

Question 1

what is the process of glycolysis

Answer 1

the process of taking glucose to from pyruvate in the cytosol of the cell to generate a few ATP

Question 2

oxidative pyruvate metabolism

Answer 2

needs to take the pyruvate from the cytosol get it into the mitochondria to generate more ATP

Question 3

how does glucose get into the muscle

Answer 3

protein transporter or facilitated transfusion “GLUT”

Question 4

how do we trap glucose

Answer 4

add a phosphate group (HK) that cost use 1 ATP

Question 5

GLUT 1

Answer 5

cell surface, at rest, always there basal uptake (non fed) low capacity

Question 6

GLUT 4

Answer 6

movers from intracellular to cell surface (regulated)
fed and active skeletal muscle
most important during exercise

Question 7

what 2 signals recruit GLUT 4 to plasma membrane in order to increase glucose uptake

Answer 7

1. insulin (feeding) (insulin signal isn’t there to tell glut 4 to get the glucose into the muscle so glucose gets stuck in the blood)
2. muscle contraction (exercise)

Question 8

insulin signalling cascade

Answer 8

• pepide hormone
  -binds to a specific receptor
• kinase phoslate to tell glut 4 vesicle to go the muscle membrane to get glucose into the cell

Question 9

doesnt insulin go down during exercise ?

Answer 9

its not just the concentration in the blood there are other factors
- depends on blood concentration and muscle blood flow

Question 10

trapping glucose

Answer 10

HK needs to trap glucose by adding a phosphate group to the glucose making it stuck to the muscle

Question 11

process in muscle

Answer 11

glucose uptake in the muscle trapped by HK to make glucose 6 phosphate then that can be used for glycolysis or stored as glycogen

Question 12

process in the liver

Answer 12

glucose uptake in the muscle trapped by HK to make glucose 6 phosphate then that can be used for glycolysis or stored as glycogen
- liver can produce glucose, by mobilized it with the enzymes glucagon and epinephrine to get it out of the liver to maintain blood glucose
-b/c the liver has glucose 6 phosphatase to take off the phosphate group

Question 13

Glucose + ATP __

Answer 13

HK = glucose 6 phosphate + ADP

Question 14

HK has a low Km

Answer 14

to be taked in the muscle easiliy

Question 15

Glucokinase has a high Km

Answer 15

we don’t want all the glucose to by trapped in the liver

Question 16

glycogen degradation

Answer 16

?

Question 17

glycogen phosphorylase turn on

Answer 17

• non equilibrium covalent regulated
• turn on by add Pi with phosphorylase kinase to make phosphorylation

Question 18

glycogen phosphorylase turn off

Answer 18

phosphorylase phosphatase turns off

Question 19

regulation (phosphorylase kinase

Answer 19

activators - CA2+ and epinephrine (feed forwards)
inhibitor - H+

Question 20

inhibitors phosphorylase phosphatase

Answer 20

epinephrine
inhibits Phos Phosphatase as stimulates phos Kinase = potent activate of glycogolisis

Question 21

glucose is a

Answer 21

polymer
density is created through cleaves
debranching enzyme to cleave a 1,6 bond

Question 22

rate limiting step

Answer 22

PFK
allosterically inhibited by ATP
- at rest ATP levels are high and inhibit of glucose

Question 23

what influences how strong the atp binding to the allostatic site

Answer 23

to fine tune the activity of PFK
-ADP,Pi ans AMP reduce ATP binding to allosteric site increase PFK activity
-H+, citrate increase ATP binding to allostric site- reduce PRK activity