Reyes, Ariane Janelle

Quiñones, Bernadette

Quiling, Gabriel Lorenzo

-is a 10 step pathway that converts glucose, a six carbon monosaccharide, to two molecules of pyruvate

-derived from the Greek glykys meaning sweet and lysis meaning splitting

Glycolysis

-divided into two parts: energy - investment phase and energy - generating phase

Energy-investment phase comprises steps 1-5. The addition of 2 phosphate group requires the energy stored in two ATP molecules. Cleavage of a carbon-carbon bond forms 2 3-carbon products

Anaerobic pathway ( Embden-Meyerhof pathway)

Energy-generating phase comprises steps 6-10. each of the three-carbon products is ultimately oxidized, forming NADH, and two high energy phosphate bonds are broken to form two ATP molecules

Anaerobic pathway ( Embden-Meyerhof pathway)

Coenzyme NAD+ is a biological oxidizing agent that converts C-H bonds to C-O bonds. In the process, NAD+ is reduced to NADH + H+.

The phosphorylation of ADP requires energy and forms ATP, a high-energy nucleoside triphosphate.

The hydrolysis of ATP releases energy and forms ADP

Step 1 – begins with the phosphorylation catalyzed by a hexokinase of glucose to form glucose 6-phosphate.

Step 2- is the isomerization of glucose 6-phosphate catalyzed by Phosphoglucoisomerase to fructose 6-phosphate takes place with an isomerase enzyme

Steps in glycolysis

Step 3- is the phosphorylation catalysed by Phosphofructokinase yielding fructose 1,6 – biphosphate

Step 4- cleavage of fructose 1,6 biphosphate catalysed by Aldolase to form 2 three-carbon products: dihydroxyacetone phosphate and glyceraldehyde 3-phosphate

Steps in glycolysis

Step 5- as glyceraldehyde 3-phosphate continues in it’s step in glycolysis, dihydroxyacetone phosphate is isomerized by Triose phosphate isomerase to form glyceraldehyde 3-phosphate.

Step 6- is the oxidation of the –CHO group of glyceraldehyde 3-phosphate and phosphorylation with HPO₄ ²⁻ to form 1,3 bisphosphoglycerate. Oxidizing agent NAD+ is reduced to NADH + H+

Steps in glycolysis

Step 7- is the transfer of a phosphate group from 1,3- bisphosphoglycerate to ADP forms 3-phosphoglycerate which was catalyzed by Phosphoglycerate kinase and generates ATP

Step 8- isomerization of the phosphate group catalyzed by Phosphoglycerate mutase to form 2-Phosphoglycerate

Steps in glycolysis

Step 9- step in which there is a loss of water to form phosphoenolpyruvate which was catalyzed by Enolase.

Step 10- transfer of a phosphate catalysed by Pyruvate kinase to form ATP and pyruvate. Thus, one NADH molecule is produced in step 6 and two ATPs are formed in steps 7 and 10 for each glyceraldehyde 3-phosphate

Steps in glycolysis

also known as krebs cycle or tricarboxylic acid (TCA) cycle

Series of eight reactions in which the acetyl group of acetyl-COA is oxidized to carbon dioxide and water. As these reactions takes place, many reduced coenzymes (both NADH and FADH₂) are formed.

Aerobic sequence (citric acid cycle

Two ATP molecules are used in the energy-investment phase (steps 1 and 3) and four molecules of ATP are formed in the energy-generating phase (steps 7 and 10). The net result is the synthesis of two molecules of ATP from glycolysis

Net result of glycolysis

•Fructose is obtained by the hydrolysis of the disaccharide sucrose, found in sugar beets and sugarcane

•Galactose is obtained by the hydrolysis of the dissacharide lactose in milk

•Mannose is obtained from polysaccharides in fruits such as cranberries and currants

Glycolysis and other hexoses

Acetyl CoA, CH₃COSCoA, is formed under aerobic conditions

Lactate, CH₃CH(OH)CO2⁻, is formed under anaerobic conditions.

Ethanol CH₃CH2OH, is formed in fermentation

Fate of pyruvate

Cancerous tumors depend largely on glycolysis to supply their energy needs

Glycolysis and cancer cells