Ch 6 Cellular Respiration

Energy for life ECOSYSTEM Photosynthesis in chloroplasts Glucose Cellular respiration in mitochondria H2OH2O CO 2 O2O2   (for cellular work) ATP Heat energy

Breathing vs Cellular Respiration Breathing- gas exchange Cellular respiration- aerobic harvesting of energy from food molecules by cells

Cellular Respiration Stores energy in ATP C 6 H 12 O 6 + 6O2O2 Glucose Oxygen 6 CO 2 Carbon dioxide + 6 H2OH2O Water + ATPs Energy

Cell Respiration

Redox Oxidation- loss of e- Reduction- addition of e- Loss of hydrogen atoms (oxidation) 6 CO H 2 O + Energy Gain of hydrogen atoms (reduction) (ATP) C 6 H 12 O O 2

Glucose Oxidation Dehydrogenase NAD + 2 H e – Oxidation Dehydrogenase Reduction NAD H NADH+H+H+ (carries 2 electrons)

ETC Electron Transport Chain ATP NAD + NADH H+H+ H+H+ 2e – Electron transport chain Controlled release of energy for synthesis of ATP + O2O2 H2OH2O 1212

Cell Respiration

Glycolysis Splits sugar Breaks Glucose into 2 three C sugars Yields 2 pyruvate molecules – Net gain of +2 ATP Glucose NAD ADP NADH2 P2 2 ATP 2 + H+H+ 2 Pyruvate

Glycolysis 2 Pyruvate Substrate-level phosphorylation – Transfer of P from substrate to ADP Energy banked in ATP and NADH  ADP ATP Enzyme Product Enzyme P P P Substrate

Formation of Acetyl CoA

Krebs Cycle

Oxidative Phosphorylation OXIDATIVE PHOSPHORYLATION

Stopping the chain ATP H+H+ O2O2 H2OH2O 1212 H+H+ NAD + NADH FADH 2 FAD PADP + Chemiosmosis + 2 Electron Transport Chain H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ ATP synthase DNP H+H+ H+H+ H+H+ Rotenone Cyanide, carbon monoxide Oligomycin DNP

ATP yield Cytoplasm Glucose FADH 2 Mitochondrion Maximum per glucose: OXIDATIVE PHOSPHORYLATION (Electron Transport and Chemiosmosis) CITRIC ACID CYCLE Electron shuttle across membrane 2 NADH (or 2 FADH 2 ) 2 Acetyl CoA GLYCOLYSIS 2 Pyruvate About 38 ATP  about 34 ATP by substrate-level phosphorylation by oxidative phosphorylation  2 ATP by substrate-level phosphorylation  2 ATP

Fermentation Glucose NADH NAD ADP P ATP 2 NADH 2 NAD ADP P ATP2 2 Pyruvate 2 Lactate GLYCOLYSIS Lactic acid fermentation NADH NAD NADH2 NAD Pyruvate 2 Ethanol Alcohol fermentation Glucose CO 2 2 released  2  2

Biosynthesis Cells, tissues, organisms ProteinsFatsCarbohydrates Glucose ATP needed to drive biosynthesis CITRIC ACID CYCLE Acetyl CoA GLUCOSE SYNTHESIS Pyruvate Amino acids GlycerolSugarsFatty acids Amino groups G3P ATP