kreb cycle

Question 1

what does high energy/ high ATP tell the TCA cycle?

Answer 1

to stop

Question 2

would increase in ATP/NADH/GTP/ Succinyl CoA inhibit or activate the TCA cycle?

Answer 2

inhibit- tells the cell to slow down because it does not need to make any more energy

Question 3

what are the common activators of the TCA cycle?

Answer 3

calcium and ADP

Question 4

What are the 4 regulated enzymes?

Answer 4

citrate synthetase, isocitrate dehydrogense, alpha ketogluterate dehydrogenase, succinate dehydrogenase

Question 5

how is citrate synthatase activated?

Answer 5

by substrate availabilty

Question 6

what inhibits citrate synthetase?

Answer 6

ATP, NADH, succinly CoA and fatty acyl CoA

Question 7

what is citrate synthetase activated by?

Answer 7

calcium and ADP

Question 8

what is isocitrate inhibited by?

Answer 8

ATP, NADH

Question 9

What is isocitrate activated by?

Answer 9

ADP, Calcium

Question 10

what is special about alph ketoglutarate?

Answer 10

it requires the same coenzymes as pyruvate dehydrogenase

Question 11

what activates alpha KG dehydrogenase?

Answer 11

calcium

Question 12

what inhibits alpha KG dehydrogenase?

Answer 12

ATP, GTP, NADH, and succinyl CoA

Question 13

what activates succinate dehydrogenase?

Answer 13

ADP, inorganoc phosphate and succinate (negative feedback)

Question 14

what inhibits succinates dehydrogenase?

Answer 14

OOA the end product

Question 15

will the inhibition of one enzyme stop the TCA cycle completely?

Answer 15

yes

Question 16

What does citrate inhibit in glycolysis?

Answer 16

PFK-1

Question 17

why is citrate important for the TCA cycle?

Answer 17

it generates energy

Question 18

how much ATP is generated in glycolysis?

Answer 18

8

Question 19

How much ATP is generated from PDH?

Answer 19

2 NADH = 2x3=6ATP

Question 20

How much ATP is generated by the TCA cycle?

Answer 20

24 (6 NADH =3x6=18 + 2 FADH2= 2x2=4) and have to multiple by two because we have 2 pyruvates

Question 21

where is FADH2 and NADH produced?

Answer 21

in the matrix

Question 22

what can produce acetyl CoA?

Answer 22

triglycerides(free fatty acid, beta oxidation), glycogen (glucose, oxidation, glyolysis), protein (amino acids, proetolysis, deamination of oxidation)

Question 23

what is the first molecule that is formed from the loss of CO2?

Answer 23

alpha keto glutarate

Question 24

what is the second molecule formed from the loss of C02?

Answer 24

Succinyl CoA

Question 25

if have a deficiency in making the enzyme that link glycolysis and the TCA cylce, what will be lost?

Answer 25

30 ATP

Question 26

if pyruvate dehydrogenase is absent what will happen?

Answer 26

pyruvate will be stuck and the TCA cycle will not be able to start

Question 27

if pyruvate dehydrogenase is absent, what is the fates of pyruvate?

Answer 27

there is an increase in lactate, alanine, no Acetyl CoA, and reduction in ATP

Question 28

what are the clinical features of pyruvate dehydrogenate dificency?

Answer 28

lactic acidosis, neurologic defects, myopathy, usually fatal at early age

Question 29

what enzymes will thiamine deficiency change?

Answer 29

alpha KG dehydrogenase in the TCA cycle and pyruvate dehydrogenase in glycolysis

Question 30

what does asernic posioning bind to and inhibit in the TCA cycle?

Answer 30

lipolic acid

Question 31

why is it bad that arsenic acid binds to lipolic acid?

Answer 31

because lipolic acid is needed for the activity of dihydrolipoyl transacetylase (e2) needed for the TCA cycle

Question 32

what result in the inhibition of dihdrolipoyl trasacetylase (E2)?

Answer 32

lactic acidodsis, neurological defects, brain and can lead to death

Question 33

what other enzyme does arsenic affect?

Answer 33

alpha KG DH and branched chain ketoacid DH

Question 34

what inhibits aconitase?

Answer 34

fluroacetate

Question 35

what are the vitamin deficiencies in the citric acid cycle?

Answer 35

niacin (B3), riboflavin (B2), thiamine (B1), panthothenate-CoA, Cobalamine

Question 36

what does malonate inhibit?

Answer 36

succinate dehydrogenase

Question 37

what is the hereditary mitochondrial diseases that has a defect in NADH dehydrogenase (ETC)?

Answer 37

leber's hereditary optic neropathy

Question 38

what does the hereditary mitochondrial disease affect?

Answer 38

TCA, ETC, Beta ocidation of fatty acids

Question 39

what are the 2 mitocondrial myopathies going to affect?

Answer 39

oxidative wanting atp tissues, brain, heart and liver

Question 40

what are the 3 mitochondrial myopathies?

Answer 40

kearns-sayre syndrome, MELAS syndrome ( mitochondrial myopathy, lactic acidosis, and stroke like episodes), MERRF syndrome ( myoclonic epilepsy; ragged red fibers)

Question 41

what is characterized as ragged red fibers?

Answer 41

mitochondrial disorders

Question 42

what can stain a mitochondrial disorder?

Answer 42

succinic dehydrogenase stain in the inner mitochondrial matrix

Question 43

what is a good mitochondrail marker?

Answer 43

succinic dehydrogenase stain