1. The Beginning of Energy Production
Glycolysis
The Beginning of Energy Production

2. Glycolysis: Overview There are 10 steps to glycolysis
Glycolysis takes place in the cytoplasm of the cell
Each step is catalyzed by an enzyme
Glycolysis has 2 phases: Energy Investment / Energy production
The net result of glycolysis is 2ATP, 2 NADH and 2 pyruvate molecules
Glycolysis: Overview

3. Step 1 Glucose enters the cell
The energy Investment phase begins when an ATP is used to phosphorylate the glucose
The result is Glucose-6-phosphate
Step 1

4. Step 2 The glucose is quickly changed Into an isomer
FRUCTOSE-6-phophate
Step 2

5. Step 3 Another ATP is spent to add another
Phosphate group to the F6P forming
FRUCTOSE 1,6-BISPHOSPHATE (F1,6-BP)
Step 3

6. Step 4 The fructose molecule is split into 2 3 carbon sugars.
Glyceraldyhyde-3-phosphate (G3P))
Dihydroxyacetone phosphate (DHAP) (TEMPORARY)
Step 4

7. The DHAP is quickly isomerized into G3P as it is used in the rest of glycolysis.
Now we have two G3P molecules to finish the rest of the steps
Step 5

8. G3P is now oxidized as a H- molecules is removed and a phosphate molecule is added
This forms 1,3 Bisphosphoglycerate
(BPG)
Subsequently a molecule of NAD+ is reduced as the high energy electron with a hydrogen molecule (H2) is transferred forming NADH + H+
This step begins the energy production phase of glycolysis
Step 6

9. Step 7 One phosphate from BPG is removed and given to ADP forming ATP
This process is called substrate level phosphorylation
Left with 3-phosphoglycerate
Step 7

10. The phosphate on 3PG is moved creating 2-phosphoglycerate (2PG)
Step 8

11. A water molecule is removed from 2PG forming Phosphoenolpyruvate
(PEP)
Step 9

12. Each PEP molecule performs substrate level phosphorylation for a second time and ATP is produced once more.
This leaves Pyruvate
Steps 6-10 are done twice for each molecule of G3P
Step 10