Fate of Pyruvate Flashcards

1
Q

what are the 3 fates of pyruvate?

A

citric acid cycle , homolactic fermintation, alcohol fermination

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

During aerobic conditions what happens to pyruvate?

A

citric acid cycle

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

What happens to pyruvate in anaerobic conditions in muscle

A

homolactic fermintation

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

anaerobic conditions in yeast

A

alcohol fermintation

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

what 2 products are produced during alcohol fermintation?

A

co2 and ethanol

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

what product is produced during homolactic fermintation?

A

lactate

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

what is the name of the enzyme used in homolactic fermintation?

A

lactate dehydrogenase

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

do we see oxidative phosphorylation or anarobic phosphorylation during intense exercise?

A

in the muscle when demand for ATP is high and o2 is low, ATP is synthesized via anarobic glycolysis which rapidly generates ATP.

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

What is often refferred to as Reaction 11 of glycolysis?

A

Homolactic Fermintation

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

is pyruvate to lactate reversible or irreversible?

A

LDH reaction is freely reversible

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

where does homolactic fermintation occur?

A

Overall process of anaerobic glycolysis in muscle

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

Write out the reaction for homolactic fermentation

A

Glucose + 2 ADP + 2 Pi ➔ 2 lactate + 2 ATP + 2 H20 + 2 H+

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

once lactate has been created what will happen to the lactate?

A

Lactate can either be exported from the cell or converted back to pyruvate

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

What happens to Lactate produced in skeletal muscle cells ?

A

Lactate produced in skeletal muscle cells is carried by the blood to the liver, where it is used to synthesize glucose

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

why do we have the 3 phates of pyruvate?

A

WE NEED TO GATHER MORE NAD+ which is why we use one of these 3 fates.

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

What is the overall goal of homolactic fermintation?

A

The overall goal is to get more NAD+

since the NADH is losing hydrogens , it is getting oxidized. this means that we are reducing the pyruvate.

17
Q

Where do we see alcohol fermintation

A

Under anaerobic conditions in yeast

18
Q

what are the products generated in alcohol fermintation?

A

Conversion of pyruvate to ethanol and CO2

19
Q

Yeast produces ethanol and CO2 via two consecutive reactions: Describe them!

A
  1. The decarboxylation of pyruvate to form acetaldehyde and CO2 as catalyzed by pyruvate decarboxylase
    Enzyme not present in animals

2.The reduction of acetaldehyde to ethanol by NADH as catalyzed by alcohol dehydrogenase
Regenerates NAD+ for use in the GAPDH reaction of glycolysis.

20
Q

what are the 2 enzymes in alcohol fermintation

A

pyruvate decarboxylase

alcohol dehydrogenase

21
Q

True/ False pyruvate decarboxylase is not found in animals

A

True, pyruvate decarboxylase

enzyme is not present in animals

22
Q

Alcohol dehydrogenase is a reversible process, yet we only see an arrow going in one direction . Why is this?

A

Even though that step is reversible we only see an brown going in one direction . this is because that first step ( pyruvate decarboxylase) is a very negative process. due to the idea of coupling it powers the next reaction and therefore prevents it from being reversible.

23
Q

What is the name of the coenzyme that pyruvate decarboxylase has?

A

Pyruvate decarboxylase contains the coenzyme thiamine pyrophosphate (TPP; also called thiamine diphosphate; ThDP)

24
Q

what is TPp Synthesized from?

A

Synthesized from thiamine (vitamin B1)

25
Q

T/F Tpp binds covalently to pyruvate decarboxylase

A

False .Binds tightly but noncovalently to pyruvate decarboxylase

26
Q

is TPp a prostetic group?

A

Yes. TPP is an example of a prosthetic group, permanent it stays with the enzyme

27
Q

Does Tpp act as an electron sink

A

yes

28
Q

what vitamin is thiamine

A

Thiamine (vitamin B1)

29
Q

thiamine is necessary for synthesis of ____

A

thiamine is necessary for synthesis of TPP

30
Q

what is the name of the Enzyme that converts acetaldehyde to ethanol

A

Yeast alcohol dehydrogenase (YADH)

31
Q

what is the function of the Zn charge in yeast alcohol dehydrogenase

A

Zn2+ polarizes the carbonyl group of acetaldehyde to stabilize the developing negative charge in the transition state of the reaction