ellular Respiration ellular Respiration A catabolic, exergonic, oxygen (O 2 ) requiring process that uses energy extracted from macromolecules (glucose) to produce energy () and water (H 2 O). Equation for R? 6 H 12 O 6 + 6O 2 6O2 + 6H 2 O + energy glucose 1 2 Question: Plants and Animals In what kinds organisms does cellular respiration take place? Plants Autotrophs: self-producers. Animals Heterotrophs: consumers. 3 4 Mitochondria Organelle where cellular respiration takes place. Redox Reaction = Transfer of one or more electrons from one reactant to another. Two types: 1. Oxidation 2. Reduction 5 6 1
Oxidation Reaction = The loss of electrons from a substance. (think backwards) Or the gain of oxygen. Oxidation 6 H 12 O 6 + 6O 2 6O 2 + 6H 2 O + energy glucose Reduction Reaction The gain of electrons to a substance. Or the loss of oxygen. Reduction 6 H 12 O 6 + 6O 2 6O 2 + 6H 2 O + energy glucose 7 8 Breakdown of ellular Respiration Four main parts (reactions). 1. Glycolysis (splitting of sugar) Glyco = sugar Lysis = split cytoplasm, just outside of mitochondria. Glucose 2 molecules pyruvic acid Just so we re on the same page What is NADH? NAD is an electron carrier much like NADP+ (photosynthesis) Glycolysis gives off 4 electrons. 2NAD s pick up the 4 e- (2 each) and become NADH. NADH holds the electrons until they can be transferred to other molecules 9 10 Breakdown of ellular Respiration The breakdown 2. Grooming Phase migration from cytosol to matrix. 3. Krebs ycle (itric Acid ycle) mitochondrial matrix 4. Electron Transport hain (ET) and Oxidative Phosphorylation a. Also called hemiosmosis b. inner mitochondrial membrane. 11 12 2
1. Glycolysis Occurs in the cytosol just outside of mitochondria. Two phases A. Energy investment phase a. Preparatory phase (first steps). B. Energy yielding phase a. Energy payoff phase (second steps). Glycolysis is an energy releasing reaction. Is energy necessary for glycolysis to start? Why? Need to get things going. Analogy earn interest, must put in $ first 4 are released in glycolysis for a net gain of 2 ( interest is earned right away) 13 14 Total Net Yield 1. Glycolysis 2-3-Pyruvate (PYR) 2 - (Substrate-level Phosphorylation) 2 - NADH 3. Krebs ycle (itric Acid ycle) Location: mitochondrial matrix. Acetyl oa (2) bonds to Oxalacetic acid (4 - OAA) to make itrate (6). It takes 2 turns of the krebs cycle to oxidize 1 glucose molecule. Mitochondrial 15 16 3. Krebs ycle (itric Acid ycle) 4. Electron Transport hain (ET) Total net yield (2 turns of krebs cycle) 1. 2 - (substrate-level phosphorylation) 2. 6 - NADH 3. 2 - FADH 2 4. 4 - O 2 Location: inner mitochondrial membrane. Uses ET (proteins) and Synthase (enzyme) to make. ET pumps H + (protons) across inner membrane (lowers ph in inner membrane space). Mitochondrial Membrane 17 18 3
4. Electron Transport hain (ET) The H+ then move via diffusion through Synthase to make. All NADH and FADH 2 converted to during this stage of cellular respiration. Each NADH converts to 3. Each FADH 2 converts to 2 (enters the ET at a lower level than NADH). 19 20 That s all for now. Until we draw the cycles!!! 1. Glycolysis A. Energy Investment Phase: 2 2ADP + P Glucose (6) 2 - used 0 - produced 0 NADH - produced ----- Glyceraldehyde phosphate (2-3) (G3P or GAP) -- -- 21 22 1. Glycolysis Substrate-Level Phosphorylation B. Energy Yielding Phase Glyceraldehyde phosphate (2-3) (G3P or GAP) 4ADP + P 4 Pyruvate (2-3) (PYR) 0 - used 4 - produced 2 NADH - produced GAP GAP -- -- -- -- (PYR) (PYR) 23 is formed when an enzyme transfers a phosphate group from a substrate to ADP. Enzyme Example: PEP to PYR Substrate (PEP) Product (Pyruvate) O - =O -O- H 2 P P P Adenosine ADP O - =O =O H 2 P P P Adenosine 24 4
2. Grooming Phase End Products: grooming phase 3. Krebs ycle (itric Acid ycle) 1 Acetyl oa (2) OAA (4) itrate (6) 2 - NADH 2 - O 2 Krebs ycle 2 O 2 2- Acetyl oa (2) FADH 2 (one turn) 3 NAD + FAD 3 NADH 25 ADP + P 26 3. Krebs ycle (itric Acid ycle) 2 Acetyl oa (2) 4. Electron Transport hain (ET) and Oxidative Phosphorylation (hemiosmosis) 2 FADH 2 OAA (4) Krebs ycle (two turns) itrate (6) 4 O 2 6 NAD + Outer membrane membrane membrane space ristae 2 FAD 6 NADH 2 2 ADP + P 27 28 4. ET and Oxidative Phosphorylation (hemiosmosis for NADH) Intermembrane Space 1H + 2H + 3H + E T Mitochondrial Membrane higher H + concentration H + Synthas e 4. ET and Oxidative Phosphorylation (hemiosmosis for FADH 2 ) Intermembrane Space 1H + 2H + E T Mitochondrial Membrane higher H + concentration H + Synthas e NADH + H + NAD+ 2H + + 1/2O 2 (Proton Pumping) H 2 O ADP + P H + lower H + concentration 29 FADH 2 + H + (Proton Pumping) FAD+ 2H + + H 1/2O 2 O 2 ADP + P H + lower H + concentration 30 5
TOTAL YIELD 1. 04 - substrate-level phosphorylation 2. 34 - ET & oxidative phosphorylation 38 - TOTAL YIELD Total Yield Eukaryotes (Have Membranes) 02 - glycolysis (substrate-level phosphorylation) 04 - converted from 2 NADH - glycolysis 06 - converted from 2 NADH - grooming phase 02 - Krebs cycle (substrate-level phosphorylation) 18 - converted from 6 NADH - Krebs cycle 04 - converted from 2 FADH 2 - Krebs cycle 36 - TOTAL 31 32 Maximum Yield for ellular Respiration (Eukaryotes) Fermentation Glucose Glycolysis 2 (substrate-level phosphorylation) ytosol 2 Pyruvate 2 Acetyl oa Krebs ycle 6NADH ET and Oxidative Phosphorylation Mitochondria 2FADH 2 2 (substrate-level phosphorylation) 2 4 6 18 4 2 Occurs in cytosol when NO Oxygen is present (called anaerobic). Remember: glycolysis is part of fermentation. Two Types: 1. Alcohol Fermentation 2. Lactic Acid Fermentation 36 (maximum per glucose) 33 34 Alcohol Fermentation Plants and Fungi beer and wine Alcohol Fermentation End Products: Alcohol fermentation glucose 2ADP + 2 P Glycolysis 2 NAD + 2 2 Pyruvic acid 2 NAD + 2O 2 Ethanol 2 released 2 - (substrate-level phosphorylation) 2 - O 2 2 - Ethanol s 35 36 6
Lactic Acid Fermentation Lactic Acid Fermentation Animals (pain in muscle after a workout). End Products: Lactic acid fermentation Glucose 2ADP + 2 P Glycolysis 2 NAD + 2 2 Pyruvic acid 2 NAD + 2 Lactic acid 2 - (substrate-level phosphorylation) 2 - Lactic Acids 37 38 2. Grooming Phase Prokaryotes (Lack Membranes) Occurs when Oxygen is present (aerobic). 2 Pyruvate (3) molecules are transported through the mitochondria membrane to the matrix and is converted to 2 Acetyl oa (2) molecules. ytosol 2 Pyruvate 2 NAD + 2 O 2-2 Acetyl oa 39 Total Yield 02 - glycolysis (substrate-level phosphorylation) 06 - converted from 2 NADH - glycolysis 06 - converted from 2 NADH - grooming phase 02 - Krebs cycle (substrate-level phosphorylation) 18 - converted from 6 NADH - Krebs cycle 04 - converted from 2 FADH 2 - Krebs cycle 38 - TOTAL 40 Question: In addition to glucose, what other various food molecules are use in ellular Respiration? atabolism of Various Food Molecules Other organic molecules used for fuel. 1. arbohydrates: polysaccharides 2. Fats: glycerol s and fatty acids 3. Proteins: amino acids 41 42 7
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