Recap: structure of ATP ribose guanine inorganic phosphate deoxyribose thymine organic phosphate nicotinamide cytosine adenine flavine

Recap: where in the cell? Glycolysis Phosphorylation Oxidation Link reaction Krebs cycle Oxidative phosphorylation

Recap: glycolysis

Recap: link reaction

Recap: Krebs cycle

Enzymes Glycolysis: Krebs cycle: Phosphofructokinase Decarboxylases Dehydrogenases

phosphofructokinase enzyme Regulatory enzymes glucose ↑ ATP ↑ citrate ↑ ADP ↓ ATP ↓ citrate phosphofructokinase enzyme pyruvate Krebs cycle

How much ATP has been produced? Glycolysis: Link reaction: Krebs cycle: Is this enough???

The electron transport chain

The electron transport chain Hydrogen atoms released from NADH and FADH as they are oxidised Hydrogen atoms split into protons and electrons Electrons move along the electron transport chain, losing energy at each carrier Energy is used to pump protons into intermembrane space forming an electrochemical gradient Protons move down electrochemical gradient back to matrix via ATP synthase Movement of protons drives synthesis of ATP from ADP and inorganic phosphate Protons, electrons and oxygen combine to form water, the final electron acceptor

Evidence for chemiosmosis pH of intermembrane space is lower than pH of matrix Proton gradient exists between intermembrane space and matrix Artificial vesicles created with proton pump proteins resulted in ↓ pH in vesicle Proton gradient can be used to synthesise ATP Mitochondria in pH8 solution produced no ATP Proton gradient can be used by mitochondria to make ATP Uncouplers destroyed proton gradient in mitochondria Proton gradient is required by mitochondria to make ATP

In 1997 1 NADH → 3 ATP and 1 FADH → 2 ATP! How much ATP? Oxidative phosphorylation makes ATP using energy from NADH and FADH 1 NADH → 2.5 ATP 1 FADH → 1.5 ATP More cutbacks: In 1997 1 NADH → 3 ATP and 1 FADH → 2 ATP!

How much ATP? Stage of respiration Molecules produced Number of ATP molecules Glycolysis Link reaction (x2) Krebs cycle (x2) Total ATP =

Anaerobic respiration glucose pyruvate carbon dioxide + ethanal lactic acid ethanol

Aerobic and anaerobic respiration Where? Is oxidation complete? What are the waste products? How much energy? Where? Is oxidation complete? What are the waste products? How much energy?