Biochemistry: Catabolism of Pyruvate Flashcards
how is NADH+ reoxidised for glycolysis
via oxidative metabolism of pyruvate
where does NADH+ deliver electrons to
respiratory chain
where does the TCA cycle occur
mitochondria
what does the mitochondrial matrix contain
TCA cycle enzymes
what does the mitochondrial inner membrane contain
ETC proteins, ATP synthase and transport proteins
what enzyme catalyses the reaction that converts pyruvate to acetyl-CoA
pyruvate dehydrogenase complex
describe the TCA cycle
- a 4C molecule binds with 2C acetyl-CoA producing a 6C molecule
- 2CO2 (decarboxylation ) and 2NADH+ are released creating a 4C molecule
- GTP is released and converts ADP+pi to ATP (phosphorylation)
- FADH2 is release as is NADH+ again
- cycle happens again
how are - carbohydrates - lipids - amino acids converted to take part in the TCA cycle
- carbohydrates are all broekn down to glucose then pyruavte via glycolysis
- all lipid are broken down to pyruvate via beta-oxidation
- amino acids can be converted into TCA cycle intermediates
what one TCA cycle enzyme isnt associated with the mitochondrial matrix and where is it associated with
- succinate dehydrogenase
- inner mitochondrial membrane
what are the controls of the TCA cycle
- ATP, NADH+ and acetyl-CoA inhibit the TCA cycle as excess energy is present
- ADP and NAD+ activate the TCA cycle as there is a lack of energy
- high succinyl-CoA and acetyl-CoA activate the TCA cycle as precursors are plentiful
what are the products of the TCA cycle
- 3NADH+ + H+, FADH2, 3CO2, GTP (ATP)
after the TCA cycle what is the net gain of ATP for each glucose molecules
4 ATP (2 used in glycolysis)
what is pyruvate fermentation
pyruvate is converted into lactic acid in the mitochondrial matrix using NADH+
describe what happens in a PDC deficiency
- XX - survivable
- XY - lethal, stillborn
presents as a neurological disorder in early childhood
what type of disorder is a PDC deficiency
stage II metabolic
