Lecture Notes for Jan 29, 2009

Respiration Lecture 6, Chapter 9 Why do we eat? Why do we breathe? Overview of Catabolism Electron Transport: hydrogen ion pumps (transfer ions to other regions). Enabolysm and catabolysm are the two branches of biochemistry. Glycolosis: Breaks sugars in half Why does our metabolism combine organic compounds with oxygen? C6H12O6 + 6O2 6CO? 2 + 6H2O neg ?G This is not hte only way creatures get energy! ? CH4 + 2O2 CO? 2 + 2H2O ? C6H12O6 + 12H2 6(CH? 4) + 6H2O ? S + H2 H? 2S ? S + 2O2 SO? 4- The enviornment is very important! Oxidation Reduction (Redox) When an atom or molecule reacts with hydrogen, or when it acquires an electron, we say that it is reduced. When an atom or molecule reacts with oxygen, or when it loses an electron, we say that it is oxidized. Whenever something is oxidized, something else is reduced (and vice versa) Many energy producing reactions in the cell involve oxidation/reduction. Glycolysis Glucose 2Pyruvate? 10 reactions 10 enzymes Yield, 2ATP, 2NADH Occurs in cytosol Regulated Next Step Pyruvate is transported into mitochondria Pyruvate + CoA Acetyl CoA + CO? 2 ? If the cell needs energy Citric acid cycle? ? If the cell does not need energy fatty acid synthesis (energy storage)?