Brainscape's Knowledge GenomeTM

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


See full index

Medical Biochemistry > PPP pathway and G6PD deficiency > Flashcards

PPP pathway and G6PD deficiency Flashcards

You may prefer our related Brainscape-certified flashcards:
USMLE® Step 1 flashcards
1
Q

what are other names for the pentose phosphate pathway?

A

hexose monophosphate shunt (HMP shunt) or 6-phosphogluconate pathway

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

where does PPP occur?

A

cytosol of cells

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

what is PPP and what is it NOT?

A

its a alternate pathway for metabolism of glucose - doesn’t produce ATP or any energy

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

what does the PPP produce?

A

provides NADPH + H

provides pentoses

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

what is NADPH produced in the oxidative pathway used for?

A

reductive biosynthetic reactions

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

what are the pentoses used for?

A

nucleotide synthesis for nucleic acid synthesis RNA and DNA!

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

where is the PPP active? - important

A

liver
lactating mammary glands
adipose tissue (provides NADPH for fatty acid biosyn)
adrenal cortex
testes/ovaries (NADPH for syn of steroid hormones)
RBCs (NADPH for red. of glutathione)
WBCs and macrophages (NADPH for phagocytosis)

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

what is the regulatory enzyme?

A

glucose 6-phosphate dehydrogenase

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

what uses TPP as a coenzyme in PPP?

A

transketolase

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

what can be used to test nutritional thiamine deficiency?

A

transketolase activity in RBCs

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

what is NADPH used for in the biosynthesis of?

A

reactions in fatty acid synthesis of steroid hormones

Synthesis of nitric oxide (NO)

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

what does NADPH reduce and detoxify?

A

hydrogen peroxide

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

what is used in the cytochrome P450 system?

A

NADPH

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

NADPH is used for phagocytosis in what?

A

WBCs

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

what produces superoxide free radicals in WBCs?

A

NADPH oxidase

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

what does deficiency of NADPH oxidase cause?

A

chronic granulomatousdisease characterized by severe persistent infections
•Infections result in increased production of oxidants

17
Q

what is the major antioxidant in RBCs to detox hydrogen peroxide?

A

GSH

18
Q

what can PPP defect cause in RBCs?

A

accumulation of hydrogen peroxide because of no GSH is being produced from NADPH and there for is damages the membrane and causes hemolysis in RBCs

19
Q

what is the most common enzyme abnormality?

A

G6PD = x linked recessive- then PK

20
Q

what can G6PD deficiency result in?

A

accumulation of free radials like hydogen peroxide
formation of denatured proteins as insoluble masses = heinz bodies

Hemolytic anemia

21
Q

where does G6PD deficiency occur?

A

all cells, but more severe in RBC

22
Q

what is the only way RBCs can get NADPH?

A

PPP

23
Q

what exactly causes a deficiency in G6PD?

A

oxidative stress
infection
fava beans - Met
oxidant drugs = sulfa drugs - primaquine

24
Q

what cells are especially vulnerable to G6PD deficiency?

A

old (senile) RBCs - they have no nucleus or ribosomes and cannot synthesize new enzyme

25
Q

what does G6PD A- result in?

A

moderate form of G6PD deficiency

its a drug induced hemolytic anemia

26
Q

when do patients have hemolytic manifestations? even if the sig. portion of young RBCs with G6PD A- have sufficient levels of the enzyme?

A

when expoed to one of the precipitating factors = infection, oxidant rug, fava beans

27
Q

what are the precipitating factors(oxidants)?

A

infection
oxidant drugs = sulfa drugs/antimalarial drugs = primaquine
fava beans

28
Q

in short, what does G6PD deficiency reduce ?

A

the levels of GSH levels - can’t break down oxidants!

29
Q

how is nitric oxide synthesized?

A

nitric oxide synthase uses NADPH
oxygen
arginine

29
Q

what is Glutathione reductase coenzyme?

A

NADPH

30
Q

what is coenzyme of glutathione perioxidase?

A

Selenium

30
Q

what two major pathways in the liver use NADPH for reductive biosynthesis?

A

fatty acid de-novo synthesis and cholesterol synthesis.

31
Q

what enzymes need NADPH for drug metabolism?

A

The group of cytochrome P450 needs NADPH.

31
Q

what is coenzyme of glutathione perioxidase?

A

Selenium

32
Q

what two major pathways in the liver use NADPH for reductive biosynthesis?

A

fatty acid de-novo synthesis and cholesterol synthesis.

32
Q

what two major pathways in the liver use NADPH for reductive biosynthesis?

A

fatty acid de-novo synthesis and cholesterol synthesis.

33
Q

what enzymes need NADPH for drug metabolism?

A

The group of cytochrome P450 needs NADPH.

33
Q

what enzymes need NADPH for drug metabolism?

A

The group of cytochrome P450 needs NADPH.

Medical Biochemistry (17 decks)

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