Coordination of Energy Metabolism

Question 1

Since the brain has no significant fuel stores, during fasting or starvation what can the brain adapt to use for energy?

Answer 1

Ketone bodies

Question 2

What does resting muscle primarily use for fuel?

Answer 2

Fatty acids from the blood

Question 3

During exertion, what does skeletal muscle use for fuel?

Answer 3

Glucose from muscle glycogen, then fatty acids. It is however not released

Question 4

Why does the heart metabolism differ from skeletal muscle?

Answer 4

Its work output is more consistent

Question 5

What is the main function of adipose tissue?

Answer 5

Stored fuel to be used for energy over a long period of time

Question 6

What 2 enzymes regulate blood glucose levels?

Answer 6

Glucokinase and hexokinase

Question 7

Glucokinase is found where? Hexokinase?

Answer 7

Liver. Hexokinase is everywhere

Question 8

Does glucokinase or hexokinase love to interact with glucose more?

Answer 8

Hexokinase kM = 0.05 mmol

Question 9

Is glucokinase or hexokinase inhibited by its product?

Answer 9

Hexokinase

Question 10

When glucose is abundant why is glucokinase not inhibited?

Answer 10

So glycogen can still be synthesized for storage

Question 11

What is insulin’s function?

Answer 11

Decrease blood glucose level

Question 12

What is glucagon’s function?

Answer 12

Increase blood glucose level

Question 13

What is epinephrine’s glucose level?

Answer 13

Increase blood glucose level

Question 14

What do pancreatic beta cells secrete?

Answer 14

Insulin

Question 15

What do pancreatic alpha cells secrete?

Answer 15

glucagon

Question 16

Liver has receptors for _ and responds to _

Answer 16

Epi and glucagon and responds to both

Question 17

Muscle has receptors for _ therefore it responds to

Answer 17

Epi but no glucagon so it only responds to epi

Question 18

Epinephrine raises blood glucose level but really only as a _ response

Answer 18

stress

Question 19

AMPK is an energy sensor that is activates what?

Answer 19

Energy producing pathways (promote glucose uptake) and inhibits energy utilizing pathways to raise the energy charge level

Question 20

mTOR is active when?

Answer 20

Active during nutrient rich conditions and promote glucose uptake to promote energy utilizing pathways and maintain energy charge level

Question 21

What is the Warburg effect?

Answer 21

Cancer cells will undergo aerobic glycolysis and convert most glucose to lactate regardless of whether oxygen is present

Question 22

Cells in quiescent state (not dividing) use what metabolism?

Answer 22

Oxidative phosphorylation

Question 23

Dcells in a proliferating use what metabolism?

Answer 23

Anaerobic glycolysis - proliferative metabolism

Question 24

What metabolism do cancer cells use?

Answer 24

Aerobic glycolysis, a lot of oxygen available but cells still undergo lactic acid fermentation

Question 25

Does AMPK or mTOR promote food intake or block food intake?

Answer 25

AMPK promotes food intake because you need enery and mTOR blocks food intake because you have enough energy

Question 26

Acetyl-CoA is a molecule that links all the pathways

Answer 26

Can be made into fatty acids

Question 27

What 2 fuels can liver store?

Answer 27

TGs and glycogen

Question 28

Where do VLDLs go to store fats?

Answer 28

Adipose tissue

Question 29

TGs are hydrolyzed by what enzyme?

Answer 29

Lipase

Question 30

What does the cori cycle in the liver produce?

Answer 30

Glucose

Question 31

Acetyl-CoA in the heart enters what pathway?

Answer 31

CAC because glucose is available to make oxaloacetate

Question 32

How does glucose know to go to the brain instead of going to the liver or skeletal muscle?

Answer 32

The brain doesnt require insulin receptors to use glucose

Question 33

What 2 fuels are left when you are starving?

Answer 33

Fatty acids and protein

Question 34

What is the mechanism of type 1 diabetes?

Answer 34

Loss of insulin production by the pancreas. Autoimmune, destroys their own beta cells

Question 35

Describe lipid overload hypothesis for diabetes

Answer 35

There is a disruption in signlaing pathway that translocates GLUT4 so glucose cant enter the cell

Question 36

Describe inflammation hypothesis for diabetes

Answer 36

Increase in adipose tissue size leads to inflammatory cytokines being secreted that bind and inhibit insulin signaling

Question 37

Untreated diabetes causes cells to be in what mode?

Answer 37

Starvation mode because they cant get glucose

Question 38

Why is oxaloacetate in short supply for untreated diabetics?

Answer 38

no glucose absorbtion inhibits oxaloacetate

Question 39

How do you treat type 1 diabetes?

Answer 39

Insulin injection or insulin pump so the glucose can be taken up by cells