Overview of Cellular Respiration Chapter 8 Cellular Energy 8.3 Cellular Respiration Overview of Cellular Respiration Organisms obtain energy in a process called cellular respiration. Formula:

Cellular respiration occurs in two main parts. Chapter 8 Cellular Energy 8.3 Cellular Respiration Cellular respiration occurs in two main parts. Glycolysis (Anaerobic) Aerobic respiration (Kreb’s Cycle)

Glycolysis: Glucose is broken down in the cytoplasm of the cell. Chapter 8 Cellular Energy 8.3 Cellular Respiration Glycolysis Glycolysis: Glucose is broken down in the cytoplasm of the cell. The process does NOT require oxygen: anaerobic

Glycolysis Occurs in the Cytoplasm—Not in an Organelle!!

Glycolysis Enzymes break down one molecule of glucose (C6H12O6) into 2 pyruvic acid (C3H4O3) molecules and 4 hydrogens The process needs 2 ATP molecules to get started—it creates 4 ATP Net gain of ATP in glycolysis is 2 ATP

Overhead Diagram

Aerobic Respiration Stage (Kreb’s Cycle) Chapter 8 Cellular Energy 8.3 Cellular Respiration Aerobic Respiration Stage (Kreb’s Cycle) Glycolysis has a net result of two ATP and two pyruvic acid molecules. Most of the energy from the glucose is still contained in the pyruvic molecules. The pyruvic acid needs to be broken down.

The two pyruvic acid molecules move into the mitochondria by active transport (this requires 2 ATP) Aerobic respiration takes place in the mitochondria (must have oxygen)

The pyruvic acid is acted upon by enzymes and broken down into acetic acid —2 ATPs are formed Acetic acid is acted upon by enzymes and broken down into citric acid CO2 and H2O are given off as waste

36 ATP are formed, but 2 are used to get the pyruvate into the mitochondria 2 ATP from glycolysis + 34 ATP from aerobic respiration = 36 ATP (net result)