Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Advanced Metabolism > Week 3 > Flashcards

Week 3 Flashcards

1
Q

What is the primary role of red blood cells?

A

transporting oxygen

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

What is the only source of energy for red blood cells?

A

Glycolysis, therefore lactate is produced. The intermediates of glycolysis can be redirected to other processes to ensure that lactate levels remain low in circulation

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

10-20% of the glycolysis intermediate 1,3 biphosphoglycerate is diverted to?

A

2, 3 biphosphoglycerate, tells RBC to give up O2 to tissues

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

10% of the glycolysis in RBC is shunted into the PPP, to provide what?

A

protection against oxidative stress

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

What does PPP provide in normal nucleated cells?

A

NADPH for biosynthetic, anabolic reactions.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the double activity of 2, 3 BPG?

A

mutase and phosphatase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

At what point doe the PPP branch from glycolysis?

A

glucose 6 phosphate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

If the pentoses needed from PPP are not needed they are shunted back to glycolysis through ?

A

fructose 6P and glyceraldehyde 3P

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

What is the electron acceptor in the PPP?

A

NADP+

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

What damage can the PPP protect against?

A

The damaging effects of oxygen free radicals - cells of the eye and erythrocytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the 2 stages of the pentose phosphate pathway?

A

irreversible redox stage and a reversible interconnection stage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What happens in the first, irreversible stage of PPP?

A

NADPH is yielded and pentose phosphate

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

What happens in the second stage, the reversible interconnection stage?

A

To reconvert pentoses to metabolic intermediates of glycolysis.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Why is the PPP important for RBCs?

A

As they do not need to generate pentoses for nucleic acid synthesis but need to make NADPH and energy .

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

Is ATP consumed or made in the PPP?

A

no ATP is consumed or made.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are the 2 purposes of PPP?

A

Provides ribose 5 phosphate for nucleotide synthesis

Provides biochemical reductants - NADPH

17
Q

What are the 3 redox enzymes for generating NADPH?

A

G6P dehydrogenase
Lactonase
6 phosphogluconate dehydrogenase

18
Q

In the redox reactions for PPP what needs to be kept at 1%?

A

NADPH needs to be kept at a very low level as it is a driver for glycolysis, TCA and OXPHOS

19
Q

What are the key enyzymes in the interconnection phase of PPP?

A

isomerases and epimerases
Transketolase (catalyzes 2C unit transfers)
Transaldolase (catalyzes 3C unit transfers to sugars)

20
Q

How is ribulose 5 phosphate in PPP converted to fructose 2 phosphate and glyceraldehyde 3 phosphate?

A

2 or 3C transfers

21
Q

In the RBC the glycolytic intermediates of the PPP continue through glycolysis to lactate, what is the result of this?

A

Glucose being only temporarily shunted away from mainstream glycolysis

22
Q

What is the rate limiting step of PPP?

A

Glucose 6 phosphate dehydrogenase

23
Q

What inhibits the rate limiting step of PPP?

A

NADH inhibits the rate limiting step of PPP: G6P dehydrogenase

24
Q

What increases the flux of the PPP Cycle?

A

An increased demand for NADPH increases the flux of the cycle by relieving inhibition of G6PD enzyme

25
Q

What increases G6PD activity and the absorption of glucose?

A

Insulin

26
Q

What is not used in ATP synthesis?

A

Electrons

27
Q

What is used in biomolecule synthesis?

A

Electrons

28
Q

What are some other uses of NADPH?

A
  • reducing ROS reactive oxygen species/chemicals
  • hydroxylation of steroid intermediates by CYP450
  • Detox of Zenobiotics - hydroxylation - Microsomal CYPs
  • Phagocytosis - pathogen destruction
  • Synthesis of nitric oxide
29
Q

What protects cells from highly reactive oxygen derivatives?

A

NADPH and Glutathione

30
Q

What is seen in a blood film of a patient suffering from glucose 6 phosphate dehydrogenase deficiency?

A

Heinz bodies

31
Q

Where does gluconeogenesis get its sources of glucose from?

A
  • Glucose from 3C compounds - glycerol, lactate, pyruvate
  • Lipids
  • Glucose from amino acid metabolism intermediates

Advanced Metabolism (8 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions