Packet #26 Chapter #9

Introduction Glycolysis is a stage common to all organisms. The chain of reactions, that make up glycolysis, convert each molecule of glucose into smaller molecules. Pyruvate Although it is not necessary to know all of the intermediate compounds/enzymes, but an appreciation for the major features is required.

Introduction II Glycolysis is derived from the Greek glykos, meaning sugar, and lysis, meaning splitting. Glycolysis is the chain of reactions that convert each molecule of glucose* into smaller pyruvate molecules. During the chain of reactions, used in the making of pyruvate, two important molecules are produced. ATP NADH

Production of ATP During Glycolysis Glycolysis produces ATP without the involvement of molecular oxygen. The production of ATP, without the use of oxygen, is called substrate level phosphorylation. During glycolysis, substrate level phosphorylation allows the net production of 2 ATP’s. Four ATP’s are produced while two ATP’s are used. Yielding two net ATP’s

Substrate Level Phosphorylation An enzyme, normally a protein kinase, removes a phosphate from the substrate and adds it to ADP to form ATP.

Production of NADH During the production of sugar intermediates, oxidation occurs when NAD + removes electrons, via the H + found on the original sugar (glucose) molecule, to make NADH. During glycolysis, two NADH’s are produced per glucose molecule.

End Product of Glycolysis Pyruvate At the end of the series of reactions, the production of the three carbon molecule, pyruvate, is complete. Two pyruvates per glucose molecule. Pyruvate, the three carbon product resulting form the splitting of sugar, passes from the cytosol to the mitochondria where the molecule is converted into CO 2 plus an acetyl group (contains two carbons—ACoA). This occurs immediately following the ten steps of glycolysis. Also formed is one NADH molecule. (per pyruvate)

Immediately Following Glycolysis Pyruvate (3C) is converted into an acetyl group (2C). Acetyl group (2C) attaches to coenzyme A (CoA) to form acetyl CoA (ACoA).

Review Glycolysis is a series of 10 steps that occurs inside the cytosol of the cell. Glucose (6C) is split into two parts that ultimately result in the production of two pyruvates (3C. 2 net ATP’s are produced per glucose molecule. 2 NADH’s are produced per glucose molecule. Immediately following glycolysis, each pyruvate (3C) is used to produce ACoA (2C) and one CO 2.

Deeper Insight I Steps #1 – 3 is the energy investment phase

Deeper Insight II Steps #4 – 5 is the cleavage of the six- carbon molecule to two three carbon sugars. Glyceraldehyde 3- phosphate

Deeper Insight III Steps #5 – 10 The energy generation phase End product be pyruvate.