Cellular Respiration How organisms make ATP

Cellular Respiration The process that produces energy (ATP) by breaking down food molecules 6O 2 + C 6 H 12 O 6  6CO 2 + 6H 2 O The process that produces energy (ATP) by breaking down food molecules 6O 2 + C 6 H 12 O 6  6CO 2 + 6H 2 O

Glycolysis: the first step in respiration Happens in the cytoplasm Glucose is split into 2 molecules of pyruvic acid Results in the net production of 2 ATP Happens in the cytoplasm Glucose is split into 2 molecules of pyruvic acid Results in the net production of 2 ATP

Two Types of Respiration Aerobic Occurs in the presence of oxygen Occurs in the mitochondria Krebs cycle – pyruvic acid is broken down into carbon dioxide in a series of energy producing steps (electron transport chain) Net ATP production: 34 ATP (per glucose molecule) + 2 ATP (glycolysis) = 36 ATP Aerobic Occurs in the presence of oxygen Occurs in the mitochondria Krebs cycle – pyruvic acid is broken down into carbon dioxide in a series of energy producing steps (electron transport chain) Net ATP production: 34 ATP (per glucose molecule) + 2 ATP (glycolysis) = 36 ATP Anaerobic Fermentation – occurs in the absence of oxygen. Two types: alcohol fermentation lactic acid fermentation Occurs in the cytoplasm Net ATP production: 2 ATP per glucose molecule

Two Pathways to ATP Aerobic 1.Glycolysis = 2 ATP 2.O 2 present = 3.Pyruvic acid enters the mitochondria 4.34 ATP produced 5.Net ATP = 36 Aerobic 1.Glycolysis = 2 ATP 2.O 2 present = 3.Pyruvic acid enters the mitochondria 4.34 ATP produced 5.Net ATP = 36 Anaerobic 1.Glycolysis = 2 ATP 2.No O 2 present = 3.Lactic acid or alcohol fermentation 4.No additional ATP produced 5.Net ATP = 2

Mitochondria Drawing Copy, color, and glue in the MITOCHONDRIA, figure 4.2 on page 108. I’ll check off next class for 10 points. Copy, color, and glue in the MITOCHONDRIA, figure 4.2 on page 108. I’ll check off next class for 10 points.