Ch 6 Cellular Respiration

Energy for life + + Heat energy ECOSYSTEM Photosynthesis in chloroplasts CO2 Glucose + + H2O O2 Cellular respiration in mitochondria ATP (for cellular work) 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 C6H12O6 + 6 O2 6 CO2 + 6 H2O + 6 O2 6 CO2 + 6 H2O + ATPs Glucose Oxygen Carbon dioxide Water Energy

Cell Respiration

Redox Oxidation- loss of e- Reduction- addition of e- C6H12O6 + 6 O2 Loss of hydrogen atoms (oxidation) C6H12O6 + 6 O2 6 CO2 + 6 H2O + Energy (ATP) Gain of hydrogen atoms (reduction)

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

ETC Electron Transport Chain NADH NAD+ ATP + 2e– Controlled release of energy for synthesis of ATP H+ Electron transport chain 2e– 1  2 O2 H+ H2O

Cell Respiration

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

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

Formation of Acetyl CoA Carbon removed from pyruvic acid producing 2 carbon acetyl group Coenxyme A added producing Acetyl CoA 12

Krebs Cycle Acetyl CoA plugged into Krebs cycle - rxn series liberates electrons to NAD & FAD 13

Oxidative Phosphorylation NAD & FAD shuttle electrons to ETC Gain another 32 ATP mols = 34 total OXIDATIVE PHOSPHORYLATION 14

Stopping the chain ATP synthase Rotenone Cyanide, Oligomycin carbon monoxide Oligomycin ATP synthase H+ H+ H+ H+ H+ H+ DNP H+ DNP FADH2 FAD 1  2 NADH O2 NAD+ + 2 H+ H+ H+ ADP + P H2O ATP H+ Electron Transport Chain Chemiosmosis

ATP yield Electron shuttle across membrane Cytoplasm Mitochondrion 2 2 NADH NADH (or 2 FADH2) 2 6 2 FADH2 NADH NADH GLYCOLYSIS OXIDATIVE PHOSPHORYLATION (Electron Transport and Chemiosmosis) 2 Pyruvate 2 Acetyl CoA CITRIC ACID CYCLE Glucose  2 ATP  2 ATP  about 34 ATP by substrate-level phosphorylation by substrate-level phosphorylation by oxidative phosphorylation Maximum per glucose: About 38 ATP

Fermentation Glucose Glucose 2 NAD+ 2 ADP 2 NAD+ 2 ADP  2 P 2  P GLYCOLYSIS GLYCOLYSIS 2 ATP 2 NADH 2 NADH 2 ATP 2 Pyruvate 2 Pyruvate 2 NADH NADH 2 CO2 2 released NAD+ 2 NAD+ 2 2 Lactate 2 Ethanol Lactic acid fermentation Alcohol fermentation

Biosynthesis ATP needed to drive biosynthesis ATP GLUCOSE SYNTHESIS CITRIC ACID CYCLE Acetyl CoA Pyruvate G3P Glucose Amino groups Amino acids Fatty acids Glycerol Sugars Proteins Fats Carbohydrates Cells, tissues, organisms