Brainscape's Knowledge GenomeTM

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


See full index

MCBM Part 1 > Mitsouras - Hexose Monophosphate Shunt > Flashcards

Mitsouras - Hexose Monophosphate Shunt Flashcards

1
Q

what are the 2 main products of the HMP

A

Ribulose 5-phosphate and NADPH

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

what is ribulose 5-phosphate used for

A

nucleotide and nucleic acids synthesis

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

what is NADPH used for

A

reproductive biosynthetic pathways and cellular detoxification

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

which branch produces 2 NADPH

A

oxidative branch

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

which branch starts with ribulose-5P

A

non-oxidative branch

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

which tissues/organs have non-oxidative HMP active

A

in rapidly dividing cells (normal and malignant)

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

what are 7 tissues/organs where the oxidative HMP is active

A

adrenal cortex (steroids), Lactating mammary glands and adipose (fatty acids), testes and ovaries (steroids), RBCs, and liver (fatty acid and cholesterol)

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

how many steps are in the oxidative branch of the HMP and what is the end product

A

3 irreversible steps and ribulose-5P

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

what regulates the first step of the oxidative branch

A

glucose-6-phosphate dehydrogenase (G6PD)

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

what is the reactant and product in the first step of the oxidative branch

A

glucose-6-phosphate –> 6-phosphoglucono-delta-lactone

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

what happens to the first step of the oxidative branch if NADPH is high

A

turns it off

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

what is the allosteric control of the first step of the oxidative branch

A

the NADPH/NADP+ ratio

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

what induces the first step in the oxidative branch to occur (turns G6PD on)

A

insulin

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

what regulates the irreversible hydrolysis the 2nd step of the oxidative branch

A

lactonase

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

what regulates the oxidative decarboxylation in the 3rd step of the oxidative branch

A

6-phosphogluconate dehydrogenase

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

what is the net result of the oxidative branch

A

2 NADPH +1 CO2 + 1 ribulose-5P per glucose-6P

17
Q

how does NADPH regulate the activity of the oxidative branch

A

NADPH will turn off the first reaction if there is too much (turn on if NADP+ is high)

18
Q

what does the non-oxidative branch turn ribulose-5P into

A

glycolytic intermediates via reversible reactions

19
Q

what two enzymes catalyze the non-oxidative branch

A

transketolase and transaldolase

20
Q

what does transketolase do

A

transfers 2C units

21
Q

what co-factor does transketolase need

A

thiamine pyrophosphate cofactor/TTP

22
Q

what does transaldolase do

A

transfers 3C units

23
Q

when is mode 1 of HMP used

A

in rapidly dividing cells - need ribulose-5P for nucleotide synthesis

24
Q

what is the reaction of mode 1

A

fructose-6P and glyceraldehyde-3P (glycolysis) -> ribulose-5P (non-oxidative)

25
Q

when is mode 2 of HMP used

A

cell needs ribulose-5P and NADPH

26
Q

what is the reaction in mode 2

A

glucose-6P (glycolysis) -> NADPH (oxidative) + Ribose (non-oxidative)

27
Q

when is mode 3 of HMP used

A

cell needs NADPH for fatty acid synthesis in liver or adipose tissue

28
Q

what is the reaction in mode 3

A

glucose-6P (glyconeogenic) -> NADPH (oxidative) -> glyceraldehyde-3P +fructose-6P (non-oxidative)
-> glucose-6P (circles around)

29
Q

when is mode 4 of HMP used

A

cell needs NADPH and ATP - (RBCs)

30
Q

what is the reaction of mode 4

A

glucose-6P -> NADPH -> glyceraldehyde-3P + fructose-6P -> ATP

31
Q

what decides what mode HMP will use

A

the cellular needs for ATP, NADPH, and ribose-5P

32
Q

what is the role of NADPH in RBCs

A

needed for production of G-SH (glutathinone in RBCs for oxidative stress)

33
Q

what is the function of glutathione in RBCs

A

reduced glutathione (G-SH) is needed to detoxify free radicals and H2O2 -> oxidative stress

34
Q

how does G6PD deficiency cause hemolytic anemia

A

G6PD deficiency -> low NADPH -> low G-SH so the RBC will have accumulation of oxidized glutathione (oxidative stress) -> hemolysis and anemia

MCBM Part 1 (29 decks)

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