Cellular Catabolism Glycolysis Packet 26 Chapter 9 Introduction

Cellular Catabolism Glycolysis 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—ACo. A). � This occurs immediately following the ten steps of glycolysis. � Also formed is one NADH molecule. (per pyruvate)

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

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