Energy Output Phase

Notes

GAP (x2)

ENZYME: Glyceraldehyde 3-phosphate dehydrogenase 

Naming: Glyceraldehyde: GAP; 3-phosphate: phosphate on carbon 3; Dehydrogenase: loses a hydrogen; Glyceraldehyde 3-phosphate dehydrogenase: This adds a phosphate on carbon 3 of GAP by losing a hydrogen to NAD+. 

• Note: NAD+ is now converted to NADH. 

1,3-Biphosphoglycerate (X2)

~The previous enzyme added a phosphate group, which is now why the name is 1,3 Diphosphoglycerate 

ENZYME: phosphoglycerate kinase

Naming explanation: Phospho- Phosphate; Glycerate- Glycerol! (Our 3 carbon sugar) ; Kinase- adds a phosphate group from a high energy donor

*Note: This kinase here makes it seem like we are going to need an input of ATP to make this. However, the 1,3-Biphosphoglycerate is now the donor, and adds a phosphate group to ADP. 

Yield: 1 ATP per GAP molecule → 2 ATP molecules in total are made. 

3-phosphoglycerate (X2)

~One of the phosphate groups has been removed!

ENZYME: Phosphoglycerate Mutase

Naming Explanation: Phospho- Phosphate; Glycerate- Glycerol (Our 3 carbon sugar) ((Notice this does not change much since the backbone stayed the same)); Mutase: So these are a group of isomerases that specifically tend to only move phosphate groups. (Also, I like to think about the fact that they sound like “mutate” so they are rearranging the molecule) 

2-phosphoglycerate (X2)

All that changed here was the position of the phosphate. It is now on carbon 2 instead of carbon 3... Why?

• This structure is important to then lead to our high energy intermediate (PEP) and catalyze the production of another ATP molecule.  

ENZYME: Enolase 

Naming Explanation: Enol: Have a C=C double bond! → Enolase, creates that double bond! 

Phosphoenolpyruvate (X2) (PEP)

~From the last enzyme, you can see the term “enol” within the new molecule! So now the molecule has a phosphate group, an enol, and a pyruvate group. 

ENZYME: Pyruvate Kinase (irreversible) 

Naming Explanation: Pyruvate→ pretty simple. Kinase: moves a phosphate group from a high energy donor. 

*Note: Again, our high energy donor is NOT ATP but is phosphoenolpyruvate 

Generates ATP from ADP!!! 

Pyruvate (X2) Final Product!