Glycolysis

After every meal we have, the food is broken down in our stomachs into small molecules. The most important molecule is known to be glucose. Glucose provides energy for all different kinds of cells and tissues in our body, allowing cellular processes to take place. This is done by the transfer of the potential energy found in the bonds of glucose into the chemical bonds of ATP, through biochemical reactions.

For the next posts, we will have a overlook in these biochemical reaction and their mechanism.

Glycolysis Overview

Glycolysis is a series of 10 connected reactions that will break down glucose and will result in pyruvate. The point of this post is not trying to get you to memorize, instead we will have a overview in some of the principles of this process, in order to comprehend it better.

The first thing to notice is that several molecules of ADP, ATP, NAD, and NADH are involved with the reactions. Glycolysis will result in the formation of two identical pyruvate molecules. Another thing to notice is that glycolysis is a anerobic process.

The 7 principles of Glycolysis

1. Glycolysis is a series of 10 connected reactions. Some of these reactions are coupled.
2. During the process of glycolysis, glucose is broken in half, hence its potential energy is rearranged in the bonds.
3. Every single reaction is exergonic (obviously). Some will small negative free energy, while others will have large.
4. Every reaction have its own enzyme. Interesting enough, cells can actually ihibit or activate them depending on how much ATP they need.
5. Glycolysis primes ATP. Which means that it actually uses 2 ATP molecules in order to make 4.
6. Glycolysis is anaerobic, but will produce two NADH molecules which will be used later on with their high potential energy levels.
7. It produces 2 pyruvate molecules, which are still full of energy and must be reused in another reaction.

What happens after glycolysis

We just talked about the formation of NADH. These molecules come from NAD, and these must me recycled, otherwise, there wouldn't be any more NAD to be used. 

Gladly there are several ways to recycle NADH. In order to do so, there must be a oxidizing agent, which can be oxygen (if present), or pyruvate itself. When pyruvate is used, it can either format lactic acid, or ethanol and carbon dioxide.

When the presence of oxygen occurs we will have what we called Oxidative Phosphorylation which we will see in later posts.