2

299678

. Krebs cycle takes place in the mitochondrial matrix and produces NADH and FADH2, Which of the following is a list of Krebs cycle intermediates?

a) Pyruvate, glucose, oxaloacetate
b) NADH, acetyl CoA, malate
c) Acetyl CoA, FADH2, Succinyl CoA
d) Acetyl CoA, malate, oxaloacetate
 

MrBeans

MrBeans
5+ Year Member
2+ Year Member
7+ Year Member
Nov 6, 2009
1,285
3
Status (Visible)
  1. Pre-Dental
Is the answer d?

I would guess this because glucose is certainly NOT a TCA intermediate, for that matter pyruvate is not either; these two compounds are associated with glycolysis.

NADH and FADH2 are products of the TCA cycle and I would not consider them intermediates. And while Acetyl CoA is not generally considered part of the TCA, I think it plays a big enough role to be considered.

Therefore, I would guess answer d.

Anyone else have any thoughts?
 

Maygyver

10+ Year Member
5+ Year Member
Jun 14, 2008
2,309
27
Status (Visible)
  1. Pre-Dental
. Krebs cycle takes place in the mitochondrial matrix and produces NADH and FADH2, Which of the following is a list of Krebs cycle intermediates?

a) Pyruvate, glucose, oxaloacetate
b) NADH, acetyl CoA, malate
c) Acetyl CoA, FADH2, Succinyl CoA
d) Acetyl CoA, malate, oxaloacetate


D. Acetyl CoA is the substrate that enters the cycle. Oxaloacetate is created after acetyl CoA, and Malate is somewhere later.
 
About the Ads

dentalWorks

Nights Watchmen
10+ Year Member
Jun 25, 2009
5,646
159
Sterling Hts, Mi
Status (Visible)
  1. Dentist
. Krebs cycle takes place in the mitochondrial matrix and produces NADH and FADH2, Which of the following is a list of Krebs cycle intermediates?

a) Pyruvate, glucose, oxaloacetate
b) NADH, acetyl CoA, malate
c) Acetyl CoA, FADH2, Succinyl CoA
d) Acetyl CoA, malate, oxaloacetate

You can right away eliminate choice a) cause pyruvate doesn't enter the krebs cycle, its the after-math of it being decarboxylated that enters (acetyl-coa)

Then right away eleminate B) and C) cause NADH and FADH2 are the by-products of the krebs, not its intermediates

Leaving you with D

I HIGHLY HIGHLY HIGHLY doubt a question like this will ever show up on the DAT. This requires too much memorization of minor details about biochemistry, and the DAT's biology section is more designed to get you to think to answer the questions, not memorize a bunch of facts to answer the questions.
 

Maygyver

10+ Year Member
5+ Year Member
Jun 14, 2008
2,309
27
Status (Visible)
  1. Pre-Dental
You can right away eliminate choice a) cause pyruvate doesn't enter the krebs cycle, its the after-math of it being decarboxylated that enters (acetyl-coa)

Then right away eleminate B) and C) cause NADH and FADH2 are the by-products of the krebs, not its intermediates

Leaving you with D

I HIGHLY HIGHLY HIGHLY doubt a question like this will ever show up on the DAT. This requires too much memorization of minor details about biochemistry, and the DAT's biology section is more designed to get you to think to answer the questions, not memorize a bunch of facts to answer the questions.


I don't really think this is too in depth though because, like you said, you can eliminate 3 answers by knowing the starting point of krebs cycle. I feel like on the DAT they might not ask it like this, but I think the main points of Krebs are probably fair game.
 

dentalWorks

Nights Watchmen
10+ Year Member
Jun 25, 2009
5,646
159
Sterling Hts, Mi
Status (Visible)
  1. Dentist
I don't really think this is too in depth though because, like you said, you can eliminate 3 answers by knowing the starting point of krebs cycle. I feel like on the DAT they might not ask it like this, but I think the main points of Krebs are probably fair game.

Yeh maybe now that I think about it, your probably right.
However, FOR SURE, you should know the locations of where the aerobic respiration takes place:

-glycolysis = cytosol (this is VERY fundamental)
-the decarboxylation of pyruvate happens in the matrix of mitochondria
-the kreb's cycle (aka cirtic acid cycle) also happens in matrix of mito
-finally the ETC happens on the INNER MEMBRANE of the mitochondria (again, very fundamental)
 

Maygyver

10+ Year Member
5+ Year Member
Jun 14, 2008
2,309
27
Status (Visible)
  1. Pre-Dental
Yeh maybe now that I think about it, your probably right.
However, FOR SURE, you should know the locations of where the aerobic respiration takes place:

-glycolysis = cytosol (this is VERY fundamental)
-the decarboxylation of pyruvate happens in the matrix of mitochondria
-the kreb's cycle (aka cirtic acid cycle) also happens in matrix of mito
-finally the ETC happens on the INNER MEMBRANE of the mitochondria (again, very fundamental)

Yeah definitely. I've seen that stuff quite a lot. I wouldn't mind getting those on my exam.
 

OU11BB

10+ Year Member
5+ Year Member
Aug 7, 2008
366
4
Status (Visible)
  1. Dental Student
answer is D, and I hope and pray i get this over some random ecology/animal behavior/animal systems question
 

MrBeans

MrBeans
5+ Year Member
2+ Year Member
7+ Year Member
Nov 6, 2009
1,285
3
Status (Visible)
  1. Pre-Dental
answer is D, and I hope and pray i get this over some random ecology/animal behavior/animal systems question

I hear ya!

I rather have this kind of question than a question that asks about Tagias, Tundras, and Deserts :p
 
This thread is more than 10 years old.

Your message may be considered spam for the following reasons:

  1. Your new thread title is very short, and likely is unhelpful.
  2. Your reply is very short and likely does not add anything to the thread.
  3. Your reply is very long and likely does not add anything to the thread.
  4. It is very likely that it does not need any further discussion and thus bumping it serves no purpose.
  5. Your message is mostly quotes or spoilers.
  6. Your reply has occurred very quickly after a previous reply and likely does not add anything to the thread.
  7. This thread is locked.
About the Ads