Cellular Respiration!

C6H12O6 + 6O2 Enzymes 6CO2 + 6H2O + energy What do living things do with food? Produce materials that bodies need to grow Materials can be converted to energy C6H12O6 + 6O2 Enzymes 6CO2 + 6H2O + energy

How do living things release energy from food?? Cellular respiration! Begins with glycolysis break down glucose  pyruvic acid small amount energy released (ATP)

Overview No oxygen Fermentation Lactic Acid Alcoholic

Glycolysis (in cytoplasm) Glucose (6C) split into: 2 pyruvic acid (3C) Result: 2 ATP & 2 NADH **4ATP formed, 2 used → net gain = 2ATP

Who uses glycolysis? ALL organisms!!! Glycolysis does NOT require oxygen → small amts of energy formed without O2 As form ATP, available NAD+ decreases  decreases ATP synthesis of glycolysis

Fermentation! Two Types NADH converted to NAD+ Anaerobic respiration - does not require O2 Two Types Lactic Acid Alcoholic

What do these items have to do with fermentation?

1. Lactic acid fermentation Pyruvic acid converted to lactic acid Lactic acid forming microorganisms used in making foods (Ex: yogurt, cheese, sour cream) Lactic acid build up in muscles causes cramps

1. Alcoholic fermentation Pyruvic acid converted to CO2 and ethyl alcohol Basis for wine and beer industry; bread

Efficiency of anaerobic respiration Glycolysis produces how many ATP molecules? TWO This is ~2% energy in glucose Can any organisms survive on fermentation alone???

Aerobic Respiration No oxygen Fermentation Lactic Acid Alcoholic

Electron transport chain Aerobic respiration Energy in pyruvic acid released using oxygen Produces 20x more ATP than glycolysis! 2 major stages Krebs cycle Electron transport chain

Where does respiration occur? Prokaryotes Respiration occurs in cytosol Anaerobic or aerobic? Eukaryotes Kreb cycle and ETC occur in mitochondria

A little about the mitochondria… 1. Pyruvic acid diffuses across membrane, enters matrix Matrix – contains enzymes used in Krebs cycle 2. Pyruvic acid reacts with Coenzyme A to form acetyl CoA (produces 2 NADH) Pyruvic Acid (C-C-C) Coenzyme A Acetyl CoA (C-C)

Part I. The Krebs Cycle Overview: energy molecules & waste products formed as Acetyl CoA broken down Acetyl CoA forms citric acid CO2 molecules are released **NADH, FADH2, ATP formed

Energy Tally Glycolysis – 2 ATP 2 NADH Conversion to – 2 NADH Acetyl CoA Krebs cycle – 2 ATP 6 NADH 2 FADH2 12 energy molecules to next stage

Part II. Electron Transport Chain Embedded in inner membrane of mitochondria Water released as waste byproduct High energy electrons converted to ATP Each NADH forms 3 ATP FADH2 forms 2 ATP

Energy Conversion Glycolysis – 2 NADH **The Rules: NADH = 3 ATP FADH2 = 2 ATP Glycolysis – 2 NADH Conversion to – 2 NADH Acetyl CoA Krebs cycle - 6 NADH 2 FADH2 ETC _____ ATP _____ ATP ____ ATP ____ ATP + 4 ATP = **TOTAL ATP Molecules: ____** ____ ATP?