Glycolysis, Kreb's Cycle and

glycolysis step 1 what happens

Glucose receives a phosphate from ATP, producing glucose-6-phosphate

glycolysis step 1 enzyme

hexokinase

step 1 glycolysis type of rxn

Phosphorylation reaction

glycolysis step 2 what happens

Glucose -6-Phosphate is rearranged to Fructose – 6- Phosphate

glycolysis step 2 enzyme name

Phospho gluco-isomerase

glycolysis step 2 name of rxn

Isomerization reaction

glycolysis step 3 what happens

Another phosphate group from ATP is attached to fructose-6-phosphate, producing Fructose -1,6,bisphosphate

glycolysis step 3 enzyme name

Phosphofructokinase

glycolysis rxn name for step 3

Phosphorylation reaction

glycolysis step 4 what happens

Fructose-1,6-bisphosphate is split into glyceraldehyde-3-phosphate (G3P) and dihydroxyacetone phosphate (DAP)

glycolysis step 4 enzyme name

Aldolase

glycolysis step 4 rxn name

HYDROLYSIS or CLEAVAGE

glycolysis step 5 what happens

The DAP produced in reaction 4 is converted into G3P, giving a total of two of these molecules per molecule of glucose.

glycolysis step 5 enzyme name

Triose phosphate isomerase

glycolysis rxn name step 5

Isomerization

glycolysis step 6 what happens

Two electrons and two protons are removed from G3P. Some of the energy released in this reaction is trapped by the addition of an inorganic phosphate group from the cytosol (not derived from ATP). The electrons are accepted by NAD+, along with one of the protons. The other proton is released to the cytosol.

glycolysis step 6 rxn name

Dehydrogenation reaction or redox reaction

glycolysis step 6 enzyme name

Glyceraldehyde-3-phosphate dehydrogenase or Triose phosphate dehydrogenase

glycolysis step 7 what happens

One of the two phosphate groups of 1,3-bisphosphoglycerate is transferred to ADP to produce ATP (substrate-level phosphorylation reaction).

glycolysis step 7 enzyme name

Phosphoglycerate kinase

glycolysis step 7 reaction name

Substrate level Phosphorylation reaction

glycolysis step 8 what happens

. 3-Phosphoglycerate is rearranged, shifting the phosphate group from the 3rd carbon to the 2nd carbon to produce 2-phosphoglycerate

glycolysis step 8 enzyme name

Phospho-glyceromutase

glycolysis step 8 rxn name

Mutase reaction—shifting of a chemical group to another within same molecule

glycolysis step 9 what happens

Electrons are removed from one part of 2-phosphoglycerate and delivered to another part of the molecule. Most of the energy lost by the electrons is retained in the product, phosphoenolpyruvate.

glycolysis step 9 enzyme name

enolase

glycolysis step 9 rxn name

dehydration

glycolysis step 10 what happens

The remaining phosphate group is removed from phosphoenolpyruvate and transferred to ADP. The reaction forms ATP and the final product of glycolysis, PYRUVATE.

glycolysis step 10 enzyme name

Pyruvate Kinase

glycolysis step 10 rxn name

Substrate –level phosphorylation

kc 1 rxn ( Condensation)

A 2-carbon acetyl group carried by COA is transferred to oxaloacetate to form citrate.

kc rxn 2 isomerization

Citrate is rearranged to Isocitrate.

kc rxn 3 first oxidation

Isocitrate is oxidized to alpha-ketoglutarate and one carbon is lost as carbon-dioxide and NAD+ is reduced to NADH and H+.

kc rxn 4 second oxidation

Alpha-Ketoglutarate is oxidized to succinyl CoA and one carbon is released as Co2, and NAD+ is reduced to NADH and H+.

kc rxn 5 Substrate -level phosphorylation

CoA is released from succinate and this produces energy which is used to convert GDP to GTP and this in turn powers conversion of ADP to ATP. The only ATP made directly by substrate level

kc rxn 6 third oxidation

Succinate is oxidized to fumarate. 2 electrons and 2 protons are removed and transferred to FAD to produce FADH2.

kc rxn 7 hydration reaction

Fumarate is converted to Malate by the addition of one water molecule

kc rxn 8 fourth oxidation

Malate is oxidized to Oxaloacetate, reducing NAD+ to NADH and H+. This regenerated oxaloacetate can reenter the cycle.