The bonds of the sugar glucose provide major much of the energy for living cells. To break down the glucose for extracting energy for cellular metabolism, glycolysis comes first. A significant portion of organisms carries glycolysis as a part of the metabolism system. This process does not need oxygen to function. Therefore, this process can occur under anaerobic conditions.
Typically, glycolysis starts with a six-carbon ring-shaped structure of an isolated glucose molecule. It ends up with two molecules of a three-carbon molecule (pyruvate). This entire process occurs in the cytoplasm wherein prokaryotic and eukaryotic cells exist.
There are two methods for the glucose to enter in heterotrophic cells. These ways are as follows –
The first one is to go through secondary active transport where the transport will take place against the glucose concentration gradient.
The second method utilizes a cluster of integral proteins named – GLUT proteins. They are also known as glucose transporter proteins. They usually facilitate the diffusion of glucose.
Additionally, the glycolysis comprises of two different phases in which the first one traps the glucose molecule in the cell. After that, it makes use of energy for a change, which will split up six-carbon sugar molecule into two three-carbon molecules. The second phase extracts energy from the molecules and keeps in the form of ATP and NADH (the reduced form of NAD^++ start superscript, plus, end superscript).
Functions of Glycolysis
Following are the functions of glycolysis –
- Glycolysis is responsible for generating ATP from the available energy. Glycolysis does that by rearranging the atoms in the monosaccharides (mainly glucose).
- Glycolysis also breaks down the glucose to offer an opening point for a complete oxidation of glucose through another pathway to carbon dioxide.
- Since glycolysis is part of aerobic respiration pyruvate, it makes citric acid cycle available.