feast or famine

Question 1

What does acetyl-CoA inhibit and activate?

Answer 1

inhibit = pyruvate dehydrogenase

activate = pyruvate carboxylase

Question 2

What does AMP signal?

Answer 2

low energy charge

Question 3

What does AMP activate regarding sugar metabolsim?

Answer 3

AMP activates glycogen phosphorylase and PFK1

Question 4

What does citrate regulate regarding fat and sugar metabolsim?

Answer 4

citrate activates acetyl-CoA carboxylase

citrate inhibits PFK1 and PFK2

Question 5

Regarding sugar metabolism, what does F16bP activate?

Answer 5

pyruvate kinase

Question 6

What does malonyl-CoA inhibit?

Answer 6

CPT-I

Question 7

cAMP induces gluconeogenesis and inhibits lipid synthesis via what?

Answer 7

CREB

Question 8

Can fatty acids cross the blood brain barrier?

Answer 8

no

Question 9

Can fatty acids be converted to glucose?

Answer 9

NO

Question 10

How do RBCs provide energy?

Answer 10

glycolysis

Question 11

What do muscles prefer for their energy needs?

Answer 11

fatty acids

Question 12

Other than fats, what else can muscles use for their enery requirements?

Answer 12

glucose and ketone bodies

Question 13

What does the heart prefer for an energy source?

Answer 13

fatty acids

Question 14

What does the brain use for energy?

Answer 14

exclusively glucose

Question 15

During the well-fed state, where is glucose stored?

Answer 15

muscle and liver

Question 16

During the well-fed state, what does the liver convert excess glucose into?

Answer 16

VLDLs

Question 17

What are amino acids used for in the well-fed state?

Answer 17

protein synthesis.

Excess AA’s are converted into glucose or ketone bodies

Question 18

During the early fast, what happens to glucose stores?

Answer 18

glycogen stores are released as glucose

Question 19

During the early fast, what happens to fatty acids and glycerol stores?

Answer 19

released from adipose tissue

Question 20

During the early fast, what does the liver produce regarding fats?

Answer 20

ketone bodies

Question 21

During the early fast, what happens to muscles?

Answer 21

amino acids are released from muscles

Question 22

During the early fast, what does the liver do to amino acids?

Answer 22

converts them to glucose and ketone bodies

Question 23

When do enzymes of the urea cycle get turned on?

Answer 23

during the early fast

Question 24

What signals the late starvation?

Answer 24

release of corticosteroids

Question 25

In the late fast, what does the brain begin to use for an energy source?

Answer 25

ketone bodies

Question 26

What other organ, excluding the liver, can produce ketone bodies?

Answer 26

Kidney

Question 27

What sort of enzyme becomes depleted during the late fast?

Answer 27

digestive enzymes Patient cannot breakdown dietary fats or carbohydrates

Question 28

Can muscles perform glugoneogenesis?

Answer 28

No

Question 29

Is lactate produced by the heart?

Answer 29

No

Question 30

What two stores of energy does the brain not have?

Answer 30

glycogen or fat

Question 31

When are urea cycle enzymes turned on? Why is this?

Answer 31

the early fast to cope with increased amino acid breakdown

Question 32

Regarding metabolism, what do corticosteroids signal?

Answer 32

metabolic rate drops and tissues consume less energy

Question 33

What does insulin do to potassium and phosphate levels?

Answer 33

insulin moves potassium and phosphate into the cells

Question 34

During the early fast, which nutrient is utilized first, glycogen or fat?

Answer 34

glycogen

Question 35

When is the urea cycled induced? Why?

Answer 35

early fast to cope with the release of amino acids

Question 36

What two nutrient stores does starvation deplete?

Answer 36

phosphate and potassium