Tca Cycle

Front 1

Where do the Partially oxidized carbons for the TCA cycle come from?

Back 1

Carbohydrates
FA
AA
Ethanol

Front 2

What happenns when the C from Carbs, FA, AA, and ethanol enter the TCA Cycle? What is produced as a result?

Back 2

they are oxidized to CO2
- reduced NUCLEOTIDES are produced from this oxidation

Front 3

What happens to the reduced nucleotides in the TCAC?

Back 3

They are sent and reoxidixed by OxPhos to Produce ATP

Front 4

Where does the TCA cycle take place?

Back 4

Mitochondria

Front 5

What is the major source of Acetyl CoA for body-wide use in the NORMAL FED state?
What enzyme catalyzes this product formation?

Back 5

Pyruvate
Pyruvate dehydrogenase

Front 6

What is the major source of Acetyl CoA in the normal FASTED state?

Back 6

FA via B-Oxidation

Front 7

What reactions link Glycolysis to the TCA cycle?

Back 7

Glycolysis produces Pyruvate
Pyruvate is biggest source of Acetyl CoA
- Acetyl Co A is used in TCA cycle

Front 8

What two products can be formed from pyruvate?

Back 8

Acetyl CoA
Oxaloacetate

Front 9

What is the function of Pyruvate Carboxylase?
What its it cofactor?
Does this reaction require energy (ATP)?

Back 9

Pyruvate Carboxylase breaks down pyruvate to Oxaloacetate.
Cofactor= Biotin which adds the CO2 making OAA a 4C molecule
- Yes it requires ATP

Front 10

What are the startig materials for TCA?

Back 10

Acetyl CoA
NAD+
FAD
Pi
GDP

Front 11

What are the products of TCA cycle?

Back 11

2 CO2 (resulting from the 2 Acetyl Co from Pyruvate from Glycolysis
NADH, FADH2, GTP

Front 12

What is the regulating enzyme of TCA?

Back 12

Isocitrate Dehydrogenase

Front 13

What is the recycled compound of the TCA cycle?

Back 13

OAA

Front 14

What are the 3 main process of the TCA cycle?

Back 14

Oxidation of Cs
- reduction of Nucleotides
- transfer of energyfrom substrate bonds to a high energy Phos bond compound

Front 15

What are the fates of CO2 produced from the TCA cycle?

Back 15

- Conversion to HCO3-
- binding to Hb in RBC
- Reconversion to CO2 in lungs
- Use as carboxylase substrate

Front 16

Can the TCA cycle function under both anaerobid and Aerobic conditions?

Back 16

NO! only AEROBIC

Front 17

Is the TCA a direct or indirect source of energy?

Back 17

Indirect.
- it's main role in energy is reducing NAD and FADH to NADH and FADH2 which will be used for ATP production in Ox Phos

Front 18

T/F: akk TCA cycle enzymes require Vitamin-derived cofactors?

Back 18

True

Front 19

What would result from deficiencies in the vitamin derived cofactors needed for the TCA cycle?

Back 19

Compromised body-wide Energy production

Front 20

What is Coenzyme A (Co-A) made from?

Back 20

Panthonthenic acid

Front 21

WHat is Co-A used for?

Back 21

Co-A is used to transfer and activate acyl groups in the TCA cycle

Front 22

What intermediates us the high energy bond from co-A?

Back 22

Citrate Synthesis
GTP production
Acetate must be converted to Acetyl CoA before it can enter the TCA cycle

Front 23

What is GTP production an example of?

Back 23

Substrate level Phosphorylation

Front 24

What are the TCA cycle Nucleotide Cofactors? How many electrons do they gain?

Back 24

NAD+= Gain of 2 e- and reduced to NADH
FAD= gain of 2e- and reduced o FADH2

Front 25

What type of enzyme is a-ketoglutarate Dehydrogenase?

Back 25

Its a Decarboxylase

Front 26

What vitamin cofactors do a-ketoglutarate utilize?

Back 26

TPP made from Thiamine
Lipoic Acid made from dietary compound lipoamide

Front 27

A-ketoglutarate is catalzyzed to Succinyl CoA via what enzyme?

Back 27

a-ketoglutarate DH along with its TPP and Lipoate co-factors

Front 28

What is succinyl CoA made from?

Back 28

- Succinyl CoA is made from A-ketoglutarate via a-ketoglutarate dehydrogenase

Front 29

is the TCA cycle reversible or irreversible?

Back 29

IRREVERSIBLE

Front 30

What are the three ways Isocitrate Dehydrogenase ic controlled?

Back 30

-allosteric ACTIVATION via it isositrate substrate (feed-fwd)
- Allosteric feed-back ACTIVATED via ADP
- Akkosteric feedback INHIBITED via NADH

Front 31

How do high amounts of Ca2+ affect isocitrate Dehydrogenase?

Back 31

Ca allosterically activated it
- this occurs in skeletal m for m. contraction and for he inc energy production needed for that contraction

Front 32

What does the TCA do with AA?

Back 32

The TCA cycle collects the Carbons from the AA that enter the cycle

Front 33

What happens to the Cs from the AA of the TCA in the FED state?

Back 33

- They are further catabolized to CO2
- converted to FA for storage as TG

Front 34

What happens to the Cs from the AA of the TCA in the FASTED state?

Back 34

- they are used as a C source for gluconeogenesis

Front 35

What is the role of transamination in the TCA cycle?

Back 35

- Produces TCA cycle intermediates from AA
- Produces AA from TCS cycle Intermediates

Front 36

What are some Transamination keto Acid/ AA pairs in TCA cycle?

Back 36

a-ketoglutarate / Glutamate
Oxaloacetate / Aspartate
Pyruvate / Alanine

Front 37

What type of process is Gluconeogenesis.

Back 37

Hepatic, Mitochondrial Process

Front 38

What makes the Carbons from AA glucogenic?

Back 38

they must have entered the TCA cycle at or afte a-ketoglutarate

Front 39

What role does Oxaloacetate have in Gluconeogenesis?

Back 39

Oxaloacetate Carbons are the starting compound for Gluconeogenesis

Front 40

How does Oxaloacetate cross into the cytosol from the mitochonrial membrane?

Back 40

It is Converted to Malate via Malate DH OR
- its converted to Aspartate via Transamination

Front 41

What are some of the starting materials for other synthetic processes that are provided by the tCA cycle?

Back 41

- Succinyl CoA (for heme synth)
- a-ketoglutarate (for glutamate synthe via transam, glutamin synth from glutamate, NT synth)
- Citrate (for FA synth)

Front 42

What does Citrate do when it leaves the liver?

Back 42

Crosses mito mem
is converted to Acetyl Co for FA synth (fed, state hepatic)

Front 43

What is the link between Glycolysis and FA synthesis from carbohydrates?

Back 43

the TCA cycle via the AA carbons that are channeled into FA synth

Front 44

What are some pathologies related to the tCA cycle?

Back 44

- Vit Deficiencies
- Lack of O2 (hypoxia, or ischemia)
- Genetic Pyruvate carboxylase deficiency causes lactic acidosis

Front 45

Decreased TCA cycle in general will decrease the ability of the body to do what?

Back 45

- Heme Synth
- Produe NT Glutamate and GABA
- Catabolize or produce AA
- CHannel AA and Lactate C in gluconeogenesis
- synth FA