In this lesson, we’ll be looking at the process of lactic acid fermentation. This is a crucial part of our muscles’ ability to regenerate after being worked out too hard.
You’ll also learn about the products of this process and even its equation. Then you can test your knowledge with a quiz!
What is Lactic Acid Fermentation?
Our muscles sometimes cry out from the strain we put on them, striving to work hard to meet our body’s demands. When we race too fast or work too hard the oxygen supply can’t keep up with the need. That is when our muscles switch from aerobic respiration to lactic acid fermentation. Lactic acid fermentation is the process by which our muscle cells deal with pyruvate during anaerobic respiration.
When our cells need energy, they break down simple molecules like glucose. The process for breaking down glucose anaerobically is called glycolysis. Glycolysis takes place in the cytosol of the cell and does not involve oxygen. The cells turn pyruvate, the products of glycolysis, into lactic acid.When glycolysis is complete, two pyruvate molecules are left. Normally, those pyruvates would be changed and would enter the mitochondrion. Once in the mitochondrion, aerobic respiration would break them down further, releasing more energy.
However, there are times when our muscle cells don’t receive the oxygen they need to perform aerobic respiration. This occurs when we work them too hard. They still need energy, so they perform glycolysis, but they cannot then perform aerobic respiration.
This is when they turn to lactic acid fermentation.
Products and Equation
The simple equation for lactic acid fermentation is glucose —glycolysis—> 2 pyruvate —fermentation–> 2 lactic acid. That is to say that glucose is broken down by glycolysis into 2 pyruvates, and then those pyruvates are fermented to produce 2 lactic acid molecules. This is shown in the diagram here.
So, in short, it’s the breakdown of a glucose molecule. Glycolysis occurs first, followed by lactic acid fermentation. The formula for lactic acid (also called lactate) is C3H6O3.
The molecule looks like the diagram here.
This is the end product of lactic acid fermentation.