It’s a big bright beautiful world Cellular Respiration It’s a big bright beautiful world

Cellular Respiration C6H12O6 + 6O2  6CO2 + 6H2O + Energy glucose ATP

Mitochondria Organelle where cellular respiration takes place. Inter membrane space Matrix Outer membrane Inner membrane

Cell Respiration has 3 Steps

Step 1: Glycolysis C-C-C-C-C-C C-C-C “Sugar Splitting” Glucose gets split in half into pyruvate What does this make? 2 Pyruvate (PYR) 2 ATP 2 Electron carriers (NADH) C-C-C-C-C-C C-C-C

Step 1 and a half: the PREP step 2 Pyruvate molecules move into the mitochondria Pyruvate broken down into Acetyl CoA This releases 2 CO2 & 2 electron carriers (NADH) Cytoplasm C 2 Pyruvate 2 CO2 2 Acetyl CoA C-C 2NADH 2 NAD+ Matrix C

Step 2: the Krebs Cycle (Citric Acid Cycle) Location: mitochondrial matrix. This is where glucose is completely broken down It takes 2 turns of the krebs cycle to completely break down 1 glucose molecule. Mitochondrial Matrix

2. Krebs Cycle (Citric Acid Cycle) 1 Acetyl CoA (2C) 3 NAD+ 3 NADH FAD FADH2 ATP ADP + P (one turn) OAA (4C) Citrate (6C) 2 CO2

2. Krebs Cycle (Citric Acid Cycle) 2 Acetyl CoA (2C) 6 NAD+ 6 NADH 2 FAD 2 FADH2 2 ATP 2 ADP + P (two turns) OAA (4C) Citrate (6C) 4 CO2

2. Krebs Cycle (Citric Acid Cycle) Total net yield: 2 ATP 8 electron carriers (NADH and FADH) 4 CO2

Step 3: the Electron Transport Chain (ETC) Location: inner mitochondrial membrane. Uses ETC and ATP Synthase (enzyme) to make ATP. ETC pumps H+ (protons) across inner membrane (lowers pH in innermembrane space). Inner Mitochondrial Membrane

3. ETC and Oxidative Phosphorylation (Chemiosmosis) Inner membrane space Matrix Cristae Outer membrane Inner membrane

3. ETC and Oxidative Phosphorylation (Chemiosmosis) NADH + H+ ATP Synthase 1H+ 2H+ 3H+ higher H+ concentration H+ ADP + lower H+ (Proton Pumping) P E T C NAD+ 2H+ + 1/2O2 H2O Intermembrane Space Matrix Inner Mitochondrial Membrane

4. ETC and Oxidative Phosphorylation (Chemiosmosis for FADH2) ATP Synthase 1H+ 2H+ higher H+ concentration H+ ADP + lower H+ concentration (Proton Pumping) P E T C FAD+ 2H+ + 1/2O2 H2O Intermembrane Space Matrix Inner Mitochondrial Membrane

TOTAL ATP YIELD in Cell resp 02 ATP – Glycolysis 02 ATP – Krebs Cycle 34 ATP – ETC = 38 ATP - TOTAL YIELD ATP!

What Happens When You Don’t Have Oxygen? Aerobic vs. Anaerobic Respiration

Fermentation Alcohol Fermentation Lactic Acid Fermentation Occurs in cytosol when “NO Oxygen” is present (called anaerobic). Glycolysis is part of fermentation. Two Types: Alcohol Fermentation Lactic Acid Fermentation

Alcohol Fermentation 2ATP C P 2NADH C C C Glycolysis 2 Ethanol 2CO2 Bacteria and Fungi  beer and wine glucose Glycolysis C C C 2 Pyruvic acid 2ATP 2ADP + 2 2NADH P 2 NAD+ C 2 Ethanol 2CO2 released 2NADH 2 NAD+

Alcohol Fermentation End Products: Alcohol fermentation 2 - ATP (substrate-level phosphorylation) 2 - CO2 2 - Ethanols

Lactic Acid Fermentation Animals (pain in muscle after a workout). Glucose Glycolysis C 2 Pyruvic acid 2ATP 2ADP + 2 2NADH P 2 NAD+ C C 2 Lactic acid 2NADH 2 NAD+ C

Lactic Acid Fermentation End Products: Lactic acid fermentation 2 - ATP (substrate-level phosphorylation) 2 - Lactic Acids

In addition to glucose, what other food molecules are used for energy? How do we get energy from them?

Catabolism of Various Food Molecules Other organic molecules are used for fuel 1. Carbohydrates: polysaccharides 2. Fats: glycerol and fatty acids 3. Proteins: amino acids