Glycolysis occurs in the cytosol, also known as intracellular fluid or cytoplasmic matrix, which is the liquid found in cells. The cytosol is separated by membranes into lots of compartments and is made of many different substances dissolved into water.
Glycolysis plays a part in cellular respiration and is a series of reactions. It makes up the first part of carbohydrate catabolism, which breaks down larger molecules into smaller ones. Why glycolysis, the larger molecules of glucose are broken down into pyruvate by using molecules of adenosine triphosphate. These ATP then become ADP. Firstly, glucose is energized by adding a high-energy phosphate from ATP which forms glucose-6-phosphate. The molecules are rearranged to become fructose-6-phosphate and a second ATP molecule is used to add a second phosphate atom, creating fructose-1,6-biphosphate. This molecule is split into a dihydrooxacetone molecule and a glyceraldehyde 3-phosphate molecule. The DHAP is rearranged into another G3P molecule, giving two G3P.
Each G3P gains a phosphorus atom and gives two electrons and a hydrogen atom to NAD+ which forms the carrier molecules, NADH. This results in the G3P molecules becoming 1,3-biphosphate glycerate. The extra phosphates are then given back to the ADP, elevating them back to ATP. The remaining phosphate on each molecule is moved to the center position, making phospho-enolpyruvate. This last phosphate is also given to ADP to make more ATP and the result is pyruvate.