The Beginning of Energy Production Glycolysis The Beginning of Energy Production

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

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

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

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

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

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

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

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

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

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

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