Question

Energetics of Phosphorylation of Glucose - making a phospho-ester

Use the data in Table to calculate ∆G'° for this reaction:

Glucose + Pi --> Glucose-6-phosphate + H2O

Give the answer in kJ/mole but only write the number in the box, no units!

Hint: Is the energy going to be positive or negative? Pay attention to the direction of the reaction!

Reflection: What does this mean? Will this happen spontaneously in your cells?

Here are screenshots of the Table we are supposed to use to solve this:

Reactants Products AG'O (kJ/mol) Type of Composite Functional Group Hydrolyzed Structures of Reactants Acetic anhydride + H2O 2 Acetic acid -91.1 Carboxylic Acid Anhydride HO Phospho-ene-ol Pyruvate (PEP) + H2O Pyruvate + Pi -61.9 Enol phospho- ester OH HO HO OH 1,3-bis-phospho- glycerate + H2O 3-phospho- glycerate + Pi -49.3 Carboxylic- Phosphoric Mixed Acid Anhydride НО-Р OH Но н. phospho-creatine + H2O creatine + Pi -43 Phospho- Amide HON ОН NH CH HOT 0 HO OH NH UDP-Glucose + H2O UMP + Glucose-1- Р -43 Phosphoric Acid Anhydride Loto OH OH OH OH NH2 ?? ATP + H20 AMP + PPI -38 Phosphoric Acid Anhydride HO OH OH OH

Answer 1

Glucose + pi-->glucose-6-phosphate + H2O, this given reaction is just opposite of the above reaction in photo.

Glucose-6-phosphate + H2O Glucose + Pi -12 Phospho- ester НО НО НО НО ОН ОН

Hence, the ∆G value is just opposite of the given in photo, then ∆G =+12 of the reaction of glucose +Pi--> glucose-6-phosphate +H2O

This means this reaction not gonna take because ∆G is positive according to thermodynamics those reactions are spontaneous in the forward direction which have negative ∆G value

Thus the reaction in the photo is possible.