Lecture 40 Flashcards

(23 cards)

1
Q

In a fasted state what pathways are on and what pathways are off?

A

ON

  • Gluconeogenesis
  • Glycogen breakdown (glycogenolysis)
  • Pyruvate carboxylase
  • Lipolysis

Off

  • Glycolysis
  • Pyruvate dehydrogenase
  • Glycogen synthesis
  • Lipogenesis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What enzyme is controlling glycolysis? Gluconeogenesis?

A
  • Citrate controls phosphofruktokinase activity (inhibits)

- Low phosphofruktokinase activity –> low fructose 2,6 P2 –> inc. gluconeogenesis/dec. glycolysis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

In a fasted state Pyruvate needs to be used to make ____ and not ____.

A
  • oxaloacetate (gluconeogenesis)

- TCA cycle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

During fasting pyruvate dehydrogenase is ___ while pyruvate carboxylase is ____. This is controlled by _____ that is derived from ______.

A
  • Inactive
  • Active (gluconeogenesis)
  • Acetyl CoA
  • b-oxidation of lipid (lipid breakdown)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

During fasting lipid breakdown is ___ and lipid synthesis is ____. What controls this?

A
  • Increased
  • Decreased
  • Long-chain acyl Co-A from b-oxidation blocks acetyl CoA carboxylase which is needed for lipid synthesis to make malonyl CoA
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

During fasted state what two hormones are contributing to stimulating glycogenolysis and gluconeogenesis? What is their mechanism of action?

A
  • Glucagon & Epinephrine
  • G-protein receptors –> cAMP –> PKA –> Enzyme phosphorylation –> Inc glycogenolysis/gluconeogenesis; Dec glycolysis/lipogenesis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the result of phosphorylating the following enzymes:

  1. Glycogen phosphorylase
  2. Glycogen synthase
  3. PFK2
  4. Pyruvate Kinase
  5. Pyruvate DHase
  6. Acetyl CoA Carboxylase
A
  1. On –> glycogen breakdown
  2. Off –> glucose storage
  3. On –> phosphatase removes F 2,6 P2
  4. Off –> inhibits glycolysis
  5. Off –> directs pyruvate to gluconeogenesis
  6. Off –> turns off lipogenesis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

AMP is a signal of ____ and ___ as a result of work/hypoxia.

A
  • Energy deprivation

- Rise

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the role of AMPK?

A

-Activated by high levels of AMP it phosphorylates key enzymes in the cell to promote glycolysis and turn off gluconeogenesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

In conditions of work/hypoxia indicate which pathway is increased/decreased:

  1. Gluconeogenesis
  2. Glycolysis
  3. Fatty acid oxidation
  4. Lipogenesis
  5. Protein synthesis
  6. cholesterol genesis
A
  1. Decreased
  2. Increased
  3. Increased
  4. Decreased
  5. Decreased
  6. Decreased
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What key enzymes does AMPK phosphorylate?

A
  1. Glycogen synthase
  2. Glycerol acyl transferase
  3. Acetyl Co-A carboxylase
  4. HMG CoA reductase
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

How are enzymes controlled at the gene level in fasted state?

A

Glucagon –> PKA –> CREB-P –> binds response elements to turn on gluconeogenesis/off lipogenesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

In a well fed state what are 3 enzymes that are promoting glycolysis?

A
  1. Glucokinase
  2. PFK –> Fructose 2,6 P2
  3. Pyruvate Kinase
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

In the well-fed state PDHase is ___ while pyruvate carboxylase is ____.

A
  • active

- inactive

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

In the well-fed state lipogenesis is turned ___ while lipolysis is turned ____. This is controlled by ____ and _____.

A
  • on
  • off
  • citrate stim of acetyl CoA carboxylase
  • malonyl CoA inhibition of b-oxidation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

In the fasted state glucagon and epinephrine promote enzyme ____ while in the well fed state insulin promotes enzyme _____

A
  • phosphorylation

- dephosphorylation

17
Q

Insulin turns off genes in gluconeogenic and fatty acid oxidation pathway by inhibiting ______ which bind to _____

A
  • forkhead txn factor

- insulin response elements

18
Q

True or False:

Excess glucose can directly regulate gene txn?

A

True

-Glucose can activate txn factor that is binding to carbohydrate response element (CarRE) which turns on lipogenesis

19
Q

Indicate whether the following enzyme would be active in the fasted or well-fed state:

  1. PFK2
  2. Malic enzyme
  3. Glucose 6-phosphatase
  4. Citrate lyase
  5. HMG CoA synthase
  6. Fructose bis-phosphatase
  7. PEP carboxykinase
  8. HMG CoA reductase
A
  1. WF
  2. WF
  3. F
  4. WF
  5. F
  6. F
  7. F
  8. WF
20
Q

Indicate whether the following enzymes will be active in the fasted or well-fed state:

  1. Pyruvate Kinase
  2. FA synthase
  3. Pyruvate carboxylase
  4. Acetyl CoA carboxylase
  5. Pyruvate Dehydrogenase
  6. Amino transferases
  7. Pentose phosphate pathway
  8. Carnitine Palmityl transferase
A
  1. WF
  2. WF
  3. F
  4. WF
  5. WF
  6. F
  7. WF
  8. F
21
Q

Carnitine is used by the ___ but synthesized in the _____

A
  • Heart and muscle

- Kidney and liver

22
Q

How is carnitine formed?

A

Proteolysis of proteins that contain a tri-methyl lysine.

-TML portion becomes carnitine

23
Q

What important metabolite is generated from Methionine, Glutamine, and Glycine? What is the significance of this? Where is it made?

A
  • Glutathione
  • Helps control oxidative damage by removing ROS
  • made in liver