Krebs Cycle

[DW3843]

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can anybody share some helpful insights on quickly (ie cramming for a test) learning the essentials of the Krebs Cycle

thanks

 

[SarahGM]

can anybody share some helpful insights on quickly (ie cramming for a test) learning the essentials of the Krebs Cycle

thanks

Hmmm... actually, since we have a test on this tomorrow...

I think the important things to know are how many carbons are involved at each phase of the cycle (2+4, then 5, then 4 again)... the major players (oxaloacetate, acetyl-CoA, alpha ketoglutarate, citrate, etc), where certain molecules can be formed, breaking off from the krebs cycle (ie alpha ketoglutarate can become glutamate, purines, etc).

Also, what each cycle produces: 2CO2, 3NADH2, 1FADH2, 1GTP. Don't quote me on this bc I haven't checked it!

Idk how in-depth you are going, but if you have to memorize something, memorize that stuff, I say!

Good luck!

 

[DW3843]

Here are some tricks that should help anyone unlucky enough to find themselves staring at the horrible cycle like a deer in headlights.

break it down into 8 reactions
#1 is Acetyl CoA (+ oxaloacetate) ----> citrate
#8 is malate ----> oxaloacetate

then memorize the intermediates along the way
make up your own mnemonic for ACIASSFMO
I have a really good that a friend of mine made up, but it might not be appropriate to post in public if you know what I mean.

1. Acetyl CoA
2. Citrate
3. Isocitrate
4. Alpha-ketoglutarate
5. Succinyl-CoA
6. Succinate
7. Fumarate
8. Malate ---> Oxaloacetate

ACIASSFMO

Other things that might help:
You get
NADH - at steps 3,4,8
FADH2 - at 6
CO2 - at 3,4
GTP - at 5

(Remeber, for each turn of the cycle you get 3 NADH, 1 FADH2, 2 CO2, and 1 GTP)


Also, if there is an enzyme that contains the word "dehydrogenase," then the reaction that it catalyzes will yield either NADH or FADH2

Major sites of regulation of the cycle are the Pyruvate Dehydrogenase omplex (PDC) and steps 1,3,4


That's all I have for now, but hopefully it will be of some use

 

[gatsbyjo]

we had to know the coenzymes/cofactors, and where certain things like malonate inhibit.

also we had to know loads about the PDH complex and alphaKG complex, and the differences between the two, also try to get a big picture idea of this all relates to ETC and glycolisis, we had a few MC questions on that

 

[SaltySqueegee]

ACIASSFMO

Golden!!! Ding Ding Ding. We have a winner!!!

It's sad how many people dont use this technique.

Try this same technique for the enzymes:

CAIαSSFM - "Kie-Ass-FM"

In a weird sort of way it makes a word.

Citrate Synthetase
Aconitase
Isocitrate Dehydrogenase
α-ketoglutarate Dehydrogenase
Succinyl-CoA Synthetase
Succinate Dehydrogenase
Fumerase
Malate Dehydrogenase

When it comes to the test all you need to know is the steps that produce NADH, FADH2 and direct substrate level Pi. Also that Isocitrate is a key regulatory step affected by ADP.

 

[donnyfire]

Cindy
Is
Kinky
So
She
Fornicates
More
Often

 

[dentate_gyrus]

Citrate Synthetase
Aconitase
Isocitrate Dehydrogenase
α-ketoglutarate Dehydrogenase
Succinyl-CoA Synthetase
Succinate Dehydrogenase
Fumerase
Malate Dehydrogenase

CAn I Keep Selling Sex For Money Officer?


Always helped me out.

 

[drlexygoat]

I wrote out the TCA cycle on my own sheet of paper a few times to make sure I had it all down. If you can redraw it yourself, you should be set.

 

[Tiki]

I'd also know what steps are allosterically regulated if I were you. 😀

 

[HoodyHoo]

Citrate Synthetase
Aconitase
Isocitrate Dehydrogenase
α-ketoglutarate Dehydrogenase
Succinyl-CoA Synthetase
Succinate Dehydrogenase
Fumerase
Malate Dehydrogenase

CAn I Keep Selling Sex For Money Officer?


Always helped me out.

Carey Ann Is Kneeling So Sweetly For Money and also for the products:

Oh Citrate Is A Silly Stupid Funny Molecule