Cell Metabolism 1 Flashcards
- How much free energy is required to hydrolyse ATP
-31 Kjmol^-1
what is the first step to glycolysis?
what enzyme is used?
why does this reaction occur?
glucose -> glucose 6 phosphate and a H+ ion
used ATP to phosphorylate glucose, so ATP becomes ADP
hexokinase enzyme
traps glucose inside the cell by means of negative charge
outline the second step to glycolysis
what is the enzyme used for this reaction
why does this reaction occur
glucose 6 phosphate to fructose 6 phosphate
phosphoglucose isomerase
so fructose can be split into equal halves when cleaved in next step
what is the third step to glycolysis?
what enzyme was used?
fructose-6-phosphate to fructose 1,6 bisphosphate
ATP to ADP as it phosphorylate fructose 6 phosphate
phosphofructokinase
- Outline step 4- what two products are made?
- via which enzyme
- what type of reaction is it
fructose 1,6 bisphosphate to glyceraldehyde 3 phosphate and dihydroxyacetone phosphate (two high energy compounds)
via aldolase
this reaction is hydrolysis
what does one of the two products formed in step 4 get converted into?(step 5)
via which enzyme?
what is the consequence of a deficiency in TPI?
the dihydroxyacetone phosphate then gets converted to glyceraldehyde 3 phosphate via TPI (triose phosphate isomerase)
fatal, most sufferers die in the first 6 years of life
outline step 6 of glycolysis reaction?
what happens to NAD in this step?
what type of reaction is this?
glyceraldehyde 3 phosphate molecules converted to 1,3 biphosphoglycerate
via glyceraldehyde 3 phosphate dehydrogenase
energy released from the reaction
used to phosphorylate NAD
to form NADH
which is used in oxidative phosphorylation to generate more ATP
redox and group transfer
outline the seventh step to glycolysis
what enzyme is used
what type of reaction is it
what happens to ADP
1,3 biphosphoglycerate to 3 phosphoglycerate
via phosphoglycerate kinase
phosphate lost from 1,3 biphosphoglycerate used to phosphorylate ADP to ATP
outline the 8th step of glycolysis
3 phosphoglycerate converted to 2 phosphoglycerate
via phosphoglycerate mutase
removal and addition of phosphoryl groups help to shuttle phosphate from position 3 to 2
isomerisation reaction
outline the ninth step of glycolysis
2 phosphoglycerate converted to phosphoenolpyruvate , waste product water
via enolase
group removal (or dehydration)
outline the 10th step of glycolysis
phosphoenolpyruvate converted to pyruvate
via pyruvate kinase
phosphorylate an ADP molecule to form ATP
group transfer
explain alcoholic fermentation of pyruvate
where does it occur
pyruvate to acetaldehyde via pyruvate decarboxylase
takes in H+ ion and produces C02
acetaldehyde to ethanol via alcohol dehydrogenase
takes in NADH and H+, produces NAD+
mostly in yeast, can occur in anaerobic conditions
explain the generation of lactate
pyruvate to lactate by lactate dehydrogenase
reversible reaction
NADH + H+ to NAD+ (when going from pyruvate to lactate- other way round if lactate to pyruvate)
using when oxygen is a limiting factor
explain how pyruvate is involved in the generation of acetyl co A
where does this reaction occur
pyruvate + HS-CoA -> acetyl CoA and C02 via pyruvate hydrogenase complex
series of reactions in the mitochondria of the cell
Acetyl Co A committed to entry of TCA cycle
- Why is it essential that NAD+ is regenerated?
- How much free energy is required to break down creatine phosphate?
Needed for dehydrogenation of glyceraldehyde-3-phosphate to produce ATP
Allows glycolysis to occur anaerobically -43 Kj/mol
