T9. METABOLIC INTEGRATION

Question 1

Why does the heart require abundant fuel?

Answer 1

Because it must maintain continuous activity.

Question 2

What does high xylulose-5-phosphate indicate?

Answer 2

Good nutrient status.

Question 3

What does high xylulose-5-phosphate activate?

Answer 3

Phosphoprotein phosphatase 2A (PP2A).

Question 4

What does PP2A activation lead to in bifunctional enzymes?

Answer 4

Activation of glycolysis and inhibition of gluconeogenesis.

Question 5

Which enzymes are affected by PP2A?

Answer 5

PFK-2 is activated

Question 6

What is the effect of activating PFK-2 and inhibiting FBP-2?

Answer 6

Increased levels of F2

Question 7

What is the effect of PP2A on acetyl-CoA carboxylase?

Answer 7

It activates it.

Question 8

What does activated acetyl-CoA carboxylase produce?

Answer 8

Malonyl-CoA.

Question 9

What is the effect of increased malonyl-CoA?

Answer 9

Inhibits FA transport into mitochondria; FA are synthesized.

Question 10

What is the main signaling mechanism of glucagon?

Answer 10

cAMP

Question 11

What is the main signaling mechanism of insulin?

Answer 11

Phosphorylation

Question 12

What are glucagon effects on the liver?

Answer 12

Increases glycogenolysis

Question 13

What are insulin effects on the liver?

Answer 13

Stimulates glucokinase

Question 14

Does muscle respond to glucagon?

Answer 14

No

Question 15

What are insulin effects on muscle?

Answer 15

Increases glucose uptake (GLUT4)

Question 16

What are glucagon effects on adipose tissue?

Answer 16

Stimulates lipolysis.

Question 17

What are insulin effects on adipose tissue?

Answer 17

Increases glucose uptake (GLUT4) and TAG synthesis.

Question 18

What are the three metabolic states?

Answer 18

Post-prandial (0–3h)

Question 19

What activates metabolism in post-prandial state?

Answer 19

GLUT4

Question 20

What is inactivated in the post-prandial state?

Answer 20

Gluconeogenesis

Question 21

What activates metabolism in post-absorption?

Answer 21

Gluconeogenesis

Question 22

What is inactivated in post-absorption?

Answer 22

GLUT4 transport

Question 23

What is activated during starvation?

Answer 23

Liver gluconeogenesis

Question 24

What happens to GLUT4 during starvation?

Answer 24

It is inactivated.

Question 25

What happens upon awakening?

Answer 25

↓ Glucose & insulin

Question 26

What is the liver’s role upon awakening?

Answer 26

Uses glycogen

Question 27

What is the adipose tissue’s role upon awakening?

Answer 27

Releases fatty acids.

Question 28

What does the brain use for energy upon awakening?

Answer 28

Glucose.

Question 29

What does the muscle use upon awakening?

Answer 29

Fatty acids

Question 30

What happens after breakfast?

Answer 30

↑ Glucose and amino acids via portal vein to liver.

Question 31

What does the liver do after breakfast?

Answer 31

Captures glucose and amino acids for gluconeogenesis.

Question 32

What does the pancreas do after breakfast?

Answer 32

Releases insulin.

Question 33

What does adipose tissue do after breakfast?

Answer 33

↓ FA release

Question 34

What does the muscle do after breakfast?

Answer 34

Takes up amino acids for protein synthesis.

Question 35

What is the metabolic effect of a lazy day?

Answer 35

↑ Glucose and insulin

Question 36

What happens on an exercise day?

Answer 36

↑ Blood flow to muscles

Question 37

What happens during intense exercise?

Answer 37

Mobilization of fat in adipose tissue.

Question 38

What hormonal changes occur during intense exercise?

Answer 38

↓ Glucose → ↑ Glucagon.

Question 39

What is the effect of party night on metabolism?

Answer 39

↑ NADH → ↓ gluconeogenesis

Question 40

What does acetate do on party night?

Answer 40

Serves as precursor for cytosolic acetyl-CoA → ↑ ketone bodies → acidosis.

Question 41

What is Type I diabetes?

Answer 41

Insulin-dependent

Question 42

What causes Type I diabetes?

Answer 42

Malfunction of pancreatic β-cells.

Question 43

What is Type II diabetes?

Answer 43

Insulin-resistant; insulin is secreted but fails to stimulate cells.

Question 44

What causes Type II diabetes?

Answer 44

Malfunction in insulin signaling.

Question 45

What are metabolic consequences of Type II diabetes?

Answer 45

↑ Glucose in blood and urine