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21 Cards in this Set
- Front
- Back
What is this?
This plus what enxzyme makes a product in the TCA cycle? |
Citrate
Citrate synthase + AcetylCoA + OAA + H2O + HSCoA makes Citrate |
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Describe the aconitase reaction.
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Citric acid (6c) is made to isocitrate.
an OH is moved from 3rd carbon to the second to last C. An isomerase rxn that is reversible |
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Describe the isocitrate dehydrogenase rxn.
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this rxn turns isocitrate into aKG (5C)
other products are NADH and CO2 THE FIRST CO2 comes off in this rxn IRREVERSIBLE |
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Describe the aKG dehydrogenase reaction.
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this rxn turns aKG into succinyl CoA (4C)
other products: NADH and CO2 IRREVERSIBLE |
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Describe the succinyl CoA synthetase reaction.
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This rxn turns Succinyl CoA into Succinate
other product: GTP IRREVERSIBLE |
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Which two rxns in the TCA cycle produce CO2 as a product?
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Isocitrate dehydrogenase and aKG dehydrogenase
Here the 6 carbon citric acid goes to a 5C then 4C molecule |
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What are the 3 rxns in the TCA cycle that produce NADH?
FADH? |
Isocitrate Dehydrogenase
aKG dehydrogenase malate dehydrogenase make NADH succinate dehydrogenase makes FADH |
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Which TCA rxn is an oxidative decarboxylation? What does this mean?
To which rxn is this similar? |
aKG dehydrogenase rxn is an oxidative carboxylation rxn.
it requires Thiamine pyrophosphate, lipoic acid, FAD and NAD and HSCoA. This is just like the Pyruvate Dehydrogenase rxn. |
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What is special about Citrate Synthase rxn?
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It is the first committed step in the TCA cycle.
Thioester bond is cleaved by hydrolysis (HSCoA chopped off) to generate a large drop in free energy. It is irreversible |
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Is the Succinate Synthetase rxn reversible?
What is this rxn an example of? |
Yes.
Substrate level phosphorylation - bc the rxn yields a GTP via cleavage of a thioester bond to get energy to make the phosphoanhydride bond. |
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Which rxn of the TCA cycle is an alkane being oxidized to an alkene?
Is the rxn reversible? |
Succinate dehydrogenase rxn. This rxn is makes Succinate (alkane) into Fumarate (alkene.
IRREVERSIBLE. The FADH produced go straight to ETC. |
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Which rxn is also part of the ETC?
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Succinate Dehydrogenase is Compex II in the ETC.
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Which rxn in the TCA cycle is an alkene hydrated to an alcohol?
Is the rxn reversible? |
Fumarase rxn makes Fumarate (alkene) into Malate (secondary alcohol).
rxn is reversible. |
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Which TCA rxn is a secondary alcohol made into a ketone?
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The Malate Dehydrogenase rxn makes malate (secondary alcohol) into oxaloacetate (ketone).
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Describe the TCA cycle in terms of molecule class starting from succinate.
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succinate is an alkane.
alkane-->alkene-->alcohol-->ketone |
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The net rxns of the TCA cycle result in the _________ of acetate into two ____.
What are the net products all together? |
The net rxns of the TCA cycle result in the OXIDATION of acetate into 2 CO2.
From one acetylCoA: 3 NADH 1 GTP 1 FADH 2 CO2 |
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COOH
. CH2 . CH2 . COOH is what molecule? Becomes what? |
Succinate
and becomes Fumarate - and alkene with the double bond in the middle bt CH2 groups. |
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Fumarate becomes what? What is added to make this happen?
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H2O is added to Fumarate with Fumarase and results in malate.
The double bond in the alkene is broken and instead malate has an -OH group on it's 2nd C. |
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O=C-COOH
. CH2 . COOH is what ? What does it turn into? |
This is Oxaloacetate. (Notice the 4 carbon structure)
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Which are the molecules in the TCA cycle that have 6 carbons?
What is the difference bt the two molecules? |
Citrate and Isocitrate have 6 carbons.
=OH on 3rd carbon in citrate. -OH on 5th carbon in isocitrate. |
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In aKG, where is the carboxyl group formed?
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on the 4th carbon.
COOH . CH2 . CH2 . C=O . COOH |