What we do with our energy Cellular Respiration What we do with our energy

Anaerobic vs. aerobic Uses no oxygen Makes a little energy Uses oxygen Makes a lot of energy

Overview Of Cellular Respiration Cellular respiration is the process that releases energy by breaking down glucose and other molecules in the presence of oxygen. Mitochondria (mainly) 3 phases Glycolysis* Krebs cycle The electron transport chain

Purpose of cellular respiration? To release energy from food molecules and make ATP! Why do we need ATP? To run chemical reactions that keep us alive and functioning.

Summary equation for Respiration Copy equation

The pathways

Stage 1- The break down of glucose This happens regardless of the amount of oxygen Glycolysis- Breakdown of glucose in the cytoplasm Anaerobic Breaks glucose into 2 pyruvate 2 ATPs required to start the reaction, 4 are produced. (gain of 2 ATPs)

Glycolysis uses 2ATP molecules but produces 4ATP molecules so there is a net gain of 2 molecules

What if there is no Oxygen?

Anaerobic respiration Not enough oxygen for aerobic respiration Fermentation-releases energy (ATP) from food molecules when there is no oxygen. (Anaerobic = no oxygen) Two types: alcoholic fermentation, lactic acid fermentation

Lactic acid vs alcoholic No oxygen Occurs in muscles Pyruvates lactate Occurs so muscles can continue making ATP Get lactate build up in muscles Causes soreness No oxygen Pyruvate  carbon dioxide & ethanol Seen in yeast and fungus Used to make beverages, food, makes dough rise

9.2 The Krebs cycle and Electron Transport

Stage 2: Production of ATP Krebs cycle Takes place in mitochondria The Krebs cycle occurs twice for each glucose molecules Once for each pyruvate Remember 2 pyruvate =1 glucose

The Krebs Cycle Aerobic (requires oxygen) Breaks pyruvic acid down into CO2 in a series of energy-extracting reactions Yields 2 ATPs and high-energy electrons for the electron transport chain

The Electron Transport Chain Uses high-energy electrons from the Krebs Cycle to convert ADP into ATP. Makes 34 ATP

Overall Cellular Respiration breaks down C6H12O6 (glucose). It produces H2O and CO2 It produces 36-38 ATPs! 2 ATP - GLYCOLYSIS 2 ATP - KREBS CYCLE 32-34 – E.T.C.

Comparing Photosynthesis & Cellular Respiration Function Energy capture Energy Release Location Chloroplasts Mitochondria Reactants CO2 & H2O C6H12O6 & O2 Products CO2 & H2O Equation 6CO2 + 6H2O -> C6H12O6 + 6O2 C6H12O6 + 6O2 > > > 6CO2 + 6H2O