Glucose molecule

What is Glycolysis?

Glycolysis a specific set of reactions that cause a basic molecule of glucose to be converted into pyruvate.  Glucose is brought into the body by consumption of Carbohydrates, Proteins, and Fats.

Gluconeogenesis is another reaction but it is designed for glucose production from the breakdown of protein.

The result of glycolysis  is the release of energy which is used in molecules such as ATP and NADH.  ATP an NADH are molecules when broken apart release energy. These molecules are similar to gasoline in vehicles which when it is broken apart, causes a reaction that moves the vehicle. In this case, for example, your legs when running or your lungs when breathing is the vehicle.

Overall there are 10 reactions involved in this process. It is seen in both anaerobic [without oxygen] and aerobic [with oxygen].

When seen in anaerobic organisms or situations – 2 ATP molecules are created

When seen in aerobic respiration the end product is then used in the Krebs cycle for additional energy production.

Approximately 34 additional molecules of ATP are made through the Krebs cycle

This Pathway Is Seen In:

–   Bacteria
–   Animals
–   Humans
–   Nearly all organisms


1.)  Preparatory phase
2.)  Pay-off Phase

1.) Preparatory phase

–   Is the first 5 steps
–   Consumption of energy to jump start the reaction
–   2 ATP are used
–   Glucose is divided into 2 smaller molecules
–   Enzymes are used to modify the reaction

2.) Pay-off Phase

–   Second part of the reaction
–   Two molecules from the preparatory phase begin the reactions
–   Therefore this phase technically occurs twice, once with each molecule
–   Result is NADH x 2 and ATP x 4
–   Since 2 ATP were used in preparatory phase the overall result is 2 ATPÂ
–   2 Pyruvate molecules are the result

Regulation of Glycolysis

–   Control on this reaction either speeds up the process or slows it down.
–   The enzymes involved are the keys
–   If too much glucose – the enzymes will work faster
–   If too little glucose – the enzymes will slow down

The reaction: