Overview of Cell Respiration • What is cell respiration? – Process that converts sugar into ATP using oxygen – Aerobic- requires oxygen – Takes place in the mitochondria – Like a mirror image of photosynthesis Glycolysis • Takes place in 3 stages – Glycolysis, Krebs Cycle, and Electron transport chain • Glycolysis must take place first – – – – Anaerobic- does not require oxygen Takes place in cytoplasm Splits glucose into two three carbon molecules- pyruvic acid 2 molecules of pyruvic acid, 2 molecules of ATP, and 2 molecules of NADH are produced Krebs Cycle • Krebs cycle- transfers energy to an electron transport chain – Breaks down three-carbon molecules from glycolysis – Makes a small amount of ATP – Releases carbon dioxide – Energy output from one molecule of pyruvic acid= 4 NADH, 1 FADH₂, and 1 molecule of ATP – Transfers energy-carrying molecules Electron Transport Chain • Electron transport chainproduces a large amount of ATP – Energy transferred to electron transport chain – 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 enters process – ATP produced – Water released as a waste product 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 Overview of Cell Respiration • Overall equation• Reactants in photosynthesis are same as the products of cell respiration 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