Brainscape's Knowledge GenomeTM

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


See full index

Biochemistry > Krebs > Flashcards

Krebs Flashcards

1
Q

Main step in Krebs prep stage

A

c-c-c pyruvate has carbon removed by pyruvate dehydrogenase (PDH) becomes Acetyl coA

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

PDH

A

Pyruvate dehydrogenase-makes ccc pyruvate into cc Acetyl coA. Huge complex made up of three enzymes and five coenzymes. Has lipoic acid covalently bound.

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

First four steps in Krebs

A

Claisen condensation
Dehydration /rehydration
Oxidative decarboxylation
Oxidative decarboxylation

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

Claisen condensation, enzyme, and intermediate

A

*citrate synthase coverts methyl in Acetyl CoA to methylene in *citrate

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

Dehydration/rehydration

A

Aconitase repositions OH group in citrate to *cis Aconitate and *Isocitrate

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

Oxidative decarboxylation

A

Isocitrate dehydrogenase oxidizes OH to carbonyl, stabilizes carbanion *alpha ketoglutarate *succinyl coA

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

Last four steps in Krebs

A

Substrate level phosphorylation
Dehydrogenation
Hydration
Dehydrogenation

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

Substrate level phosphorylation

A

Succinyl CoA synthetase hydrolyzes succinyl CoA to succinate. Thioester leads to high energy phosphate bond, negative G. GTP/ATP

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

Dehydrogenation 1

A

Succinate dehydrogenase introduces double bond in center create fumarate

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

Hydration

A

Fumarase adds water, removes double bond in fumarate creates malate

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

Dehydrogenation 2

A

Malate dehydrogenase generates carbonyl creates OAA (oxaloacetate)

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

Products of Krebs (prep included)

A

2 NADH prep
6 NADH
2 ATP
2 FADH

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

Products from glycolysis and Krebs

A

4 ATP
10 NADH
2 FADH
Ready for ETC

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

Three irreversible steps in Krebs

A

Claisen comdensation, and both oxidative decarboxylations

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

Aconitase

A

Enzyme used in dehydration/rehydration
FeS center
Cysteine residues bind to Fe

If Fe low uptake increased and storage deceased

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

Vertebrates cannot…

A

Convert Acetyl coA to carbs(or fatty acids to carbs)

17
Q

Glyoxylaye cycle

A

Bypass that allows microbes and invertebrates to convert to carbs (done by plants)

18
Q

Enzymes unique to glyoxylaye

A

Isocitrate lyase and malate synthase

19
Q

What are the three stages in Krebs

A

Acetyl coA production
Acetyl coA oxidation
ETC/oxidative phosphorylation

20
Q

OAA uniformly labeled is condensed with Acetyl coA, how much radioactivity in OAA after one cycle

A

1/2

21
Q

Acetyl coA labeled reacts with unlabeled OAA how many on OAA after one cycle

A

All

22
Q

Two CO2 produced in first cycle Krebs have their origin from

A

Two carboxyl groups from OAA

23
Q

Which enzymes are irreversible

A

Citrate synthase
Isocitrate dehydrogenase
a ketoglutarate dehydrogenase

24
Q

How many electrons from Krebs will enter ETC

A

20

25
Q

How many NADH can convert 4FE 4S to a fully reduced state

A

2

26
Q

How many intermediates in Krebs can be trannaminated to amino acids

A

Three

27
Q

Which intermediates and what amino acids

A

Pyruvate to alanine
OAA to aspartate
A ketoglutarate to glutamate

28
Q

Krebs only operates when O2 is present because

A

O2 accepts electrons from ETC

29
Q

Subsequent step after removing CO2 and attaching Acetyl group

A

Reduction of lipoic acid

30
Q

When does Krebs directly yield reducing owner NADH or FADH

A

Succinate to fumarate by succinate dehydrogenase

31
Q

If succinyl coA is labeled at C1 where in fumarate

A

Equally in C1 and C4

32
Q

What would slow or stop Krebs

A

High ATP and high NADH

33
Q

What intermediate does the glyoxylate cycle pass

A

Succinate

34
Q

Why is Claisen condensation irreversible

A

The standard free energy is so negative

35
Q

The iron in FeS clusters participate in rxns by

A

Gaining or losing electrons

36
Q

Intermediates in Krebs at used in a one step biosynthesis of

A

Amino acids

37
Q

Which intermediate is not removed by another metabolic pathway

A

Isocitrate

Biochemistry (7 decks)

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