Metabolism 2 Flashcards
What are the 3 irreversible steps of Glycolysis?
D-glucose to Glucose 6-Phosphate. Catalysed by Hexokinase
Fructose-6-Phospahte to Fructose-1,6-Bisphosphate. Catalysed by Phosphofructokinase
Phosphoenolpyruvate to Pyruvate. Catalysed by Pyruvate kinase
What are the differences between the structures of Glucose and Fructose?
The aldehyde on C1 and OH on C2 of Glucose switch places on fructose.
What are the differences between the structures of Fructose-6-Phosphate and Fructose-1,6-Bisphosphate ?
The numbers indicates where the Phosphate is.
Why are steps irreversible?
Due to their large negative Delta Gs
What is a co factor?
What is a cofactor called when it is organic?
Non-protein component of enzymes
Organic= coenzyme
What are most coenzymes derived ?
Vitamins
What is the coenzyme and function derived from niacin?
Coenzyme- NAD+
Function- oxidation/H+ transfer
NADH + H+ forms NAD+
Is this oxidation or reduction?
Reduction
The reverse is oxidation
How does pyruvate turn into L-lactase?
Pyruvate + NADH + H+ ( catalysed by lactate dehydrogenase) turns into lactate and NAD+
Where does the equilibrium lie in endergonic reactions?
in the favour of the substrate
Where does the equilibrium lie in endergonic coupled to an exergonic reactions?
in the favour of the product
What differs between GTP and ATP?
They both transfer energy but G=guanosine A= adenosine
Dephosphorylation reaction are exergonic or endergonic?
exergonic
Are oxidation reactions exergonic or endergonic?
Exergonic
Glyceraldehyde-3-phosphate is coupled with what to produce 1,3-bisphosphoglycerate?
G3P dehydrogenase and NAD+ to NADH +H+
