Ch 9- Cellular Respiration Equation for cellular respiration 6 O₂+ C₆H₁₂O₆→ 6 CO₂+ 6 H₂O + Energy Photosynthesis? 6 CO₂+ 6 H₂O + Energy→6 O₂+ C₆H₁₂O₆ Occurs in 3 stages Glycolysis- anaerobic, takes place in cytoplasm, products enter mitochondria Kreb’s Cycle- aerobic (requires oxygen), occurs in mitochondria Citric Acid Cycle Electron transport chain- aerobic, occurs in mitochondria

Main Stages of Cell respiration Glycolysis needs 2 ATP molecules to begin process What happens during glycolysis? 2 molecules of pyruvic acid, 2 molecules of ATP, and 2 molecules of NADH are produced Kreb’s Cycle- Citric Acid Cycle During cycle, pyruvic acid is broken down into carbon dioxide in a series of energy extracting reactions Energy output from one molecule of pyruvic acid= 4 NADH, 1 FADH₂, and 1 molecule of ATP NADH, FADH ₂ are high energy electron carriers

Main Stages cont. Electron transport chain- takes place in mitochondria Uses high energy electrons from Krebs cycle to convert ADP to ATP 8 NADH and 2 FADH ₂ from Kreb’s cycle Each NADH produces 3 molecules of ATP Each FADH ₂ produces 2 molecules of ATP Oxygen serves as last electron acceptor, and water is last product made

Totals Glycolysis- 2 ATP and 2 NADH 2 NADH produces 4 ATP Krebs Cycle- 2 ATP, 8 NADH, and 2 FADH ₂ Electron Transport Chain- uses NADH and FADH ₂ to produce ATP NADH produces 24 ATP FADH ₂ produces 4 ATP Total ATP molecules formed during cellular respiration= 36