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Glycolysis

Glycolysis

Description:

This lesson will describe in detail the processes that occur in the glycolysis phase of cellular respiration.

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Tutorial

What's Covered

Welcome to today’s lesson on glycolysis. Today, you will be learning about the processes that occur in the glycolysis phase of cellular respiration. Specifically, you will learn about:

  1. Cellular Respiration
  2. Glycolysis Process

1. Cellular Respiration

Glycolysis this is the first step in cellular respiration.

Term to Know

Glycolysis

The first stage of cellular respiration which breaks a molecule of glucose into two molecules of pyruvate.

Cellular respiration is a process in which ATP, or adenosine triphosphate, is produced for the cell. ATP is basically an energy storage molecule that cells use.


2. Glycolysis Process

In glycolysis, the main thing that's occurring is that one glucose molecule is being transformed into two molecules of pyruvate. Glycolysis occurs in the cytoplasm of the cell and it's an anaerobic process, meaning it does not require oxygen to happen. You'll notice later stages of cellular respiration occur within the mitochondria. However, glycolysis occurs in the cytoplasm.

The main thing that's happening is a glucose molecule is being transformed into two molecules of pyruvate.

Terms to Know

Glucose

A type of sugar used in glucose to produce ATP. Glucose is broken down in the first stage of cellular respiration.

Pyruvate

A 3 carbon sugar produced when glucose is broken down in the glycolysis phase of cellular respiration.

Glucose is basically a six carbon sugar and when glucose enters the process of glycolysis, two ATPs will donate their phosphate groups to this glucose molecule. This donation of phosphate from ATP is called phosphorylation.

Term to Know

Phopshorylation

The transfer of a phosphate group from an ATP molecule to another molecule thus the transfer of energy to that molecule.

Basically, the purpose of this is to transfer energy. ATPs are transferring their energy to this glucose molecule, so that it can go through the following phases of glycolysis-- so that glycolysis can be carried out; ATP is donating one of its phosphates.

ATP stands for adenosine triphosphate; the prefix "tri" means three so it has three phosphate groups attached to it. When an ATP gets rid of one of its phosphates, it becomes ADP, which means adenosine diphosphate, meaning it has two phosphates.

Next, the molecule is going to break down in half so that there are two three-carbon molecules still with this phosphate group attached. Then the phosphates are going to be donated back to ATP. After it donated its phosphate, it became ADP and when it gains its phosphate back, it becomes ATP again.

Then, you’re left with two three-carbon molecules and each of these molecules are a molecule of pyruvate. Now, in actuality, four molecules of ATP are being produced but since ATP was used for the process to occur, there is only have a net gain of two ATP.

Big Idea

That's what's happening in glycolysis: glucose is being broken down into pyruvate. Then pyruvate will move into the next phase of cellular respiration to produce more ATP.


Summary

Today you learned about the process of glycolysis. In order for glycolysis to happen, two molecules of ATP have to enter glycolysis. Two molecules of ATP are being used in glycolysis, and two molecules of ATP are being produced. This ATP energy actually comes from previous cycles of cellular respiration so we're using ATP that was made in previous cycles to power glycolysis, to produce more ATP here. The net gain is two ATP out of glycolysis.


Keep up the learning and have a great day!

Source: THIS WORK IS ADAPTED FROM SOPHIA AUTHOR AMANDA SODERLIND

TERMS TO KNOW
  • Glycolysis

    The first stage of cellular respiration which breaks a molecule of glucose into two molecules of pyruvate.

  • Glucose

    A type of sugar used in glucose to produce ATP. Glucose is broken down in the first stage of cellular respiration.

  • ​Pyruvate

    A 3 carbon sugar produced when glucose is broken down in the glycolysis phase of cellular respiration.

  • Phopshorylation

    ​The transfer of a phosphate group from an ATP molecule  to another molecule thus the transfer of energy to that molecule.