Energy Input Phase

Notes

Glucose (Our starting material!) 

ENZYME: Hexokinase (irreversible)

Naming explanation: Hexokinase: hex means six; Kinase: a kinase is something that transfers a phosphate group from high donor molecules. ;Hexokinase: adds a phosphate group to the 6th carbon from ATP 

• Note: The step of adding a phosphate group traps the glucose in the cell

Glucose-6-phosphate 

~The phosphate group is now on carbon 6! 

ENZYME: phosphoglucose isomerase

Naming explanation: Phosphoglucose: phosphate+glucose ; Isomerase: Makes an isomer (changes the arrangement of the molecule) ; Phosphoglucose isomerase: makes an isomer from glucose with a phosphate on it. 

Fructose-6-phosphate

~It is now a fructose sugar molecule (5 member ring instead of 6) but still has the phosphate on carbon 6. Remember: we did not lose any atoms, they were simply rearranged. 

ENZYME: Phosphofructokinase (irreversible) 

Naming Explanation: Phosphofructo: phosphate+fructose ; Kinase: again, a kinase is something that transfers a phosphate group from a high donor molecule. ; Phosphofructokinase: adds a phosphate group from ATP onto fructose-6-phosphate.

Fructose-1,6-bisphosphate

~Fructose with 2 phosphate groups in it! One on carbon 6 and now one on carbon 1. 

ENZYME: Aldolase

Naming explanation: Aldolase is an enzyme that makes aldose. GAP (one of the next molecules it makes) is an aldose. The other molecule it makes, DHAP, is a ketose, which will later have to be rearranged to become GAP as well. 

Dihydroxyacetone (DHAP) + Glyceraldehyde 3-phosphate (GAP)

ENZYME: Triose phosphate isomerase 

Triose: three carbon sugar ; Phosphate: has a phosphate group; Isomerase: rearrange the molecule to make an isomer ; Triose phosphate isomerase: Modify a 3 carbon sugar with a phosphate group into an isomer (GAP). 

• Note: look at the two structures and think about how the isomerase will have to rearrange DHAP to make GAP. 

GAP (X2)