Cellular Respiration Chapter 6

Types of Energy?????

Energy - *potential energy = stored kinetic energy = being used *forms: light, heat, mechanical, chemical, electrical, sound *potential energy = stored kinetic energy = being used *can be transformed from one type to another – -battery - chemical to electrical -roll downhill - potential to kinetic -flip light switch –mechanical to electrical to light & heat *it is the ability to do work!

Cellular Respiration C6H12O6 + 6O2  6CO2 + 6H2O (energy) A cellular process that releases energy from glucose (or other organic molecules) to produce energy (ATP). C6H12O6 + 6O2  6CO2 + 6H2O (energy) glucose ATP

What respires?

Plants and Animals/all living organisms

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

ATP & ADP

ATP & ADP

Oxidation-Reduction Reactions Transfer of one or more electrons and/or energy from one compound to another. Two parts: 1. Oxidation 2. Reduction

Oxidation Reaction The loss of electrons or energy from a compound.

Reduction Reaction The gain of electrons or energy to a compound.

Oxidation-Reduction Reactions Reactions where 1 substance loses electrons &/or energy &/or hydrogen and another substance gains electrons &/or energy &/or hydrogen O I L R G Oxidation reaction: loss of electrons &/or energy &/or hydrogen Reduction reaction: gain of electrons &/or energy &/or hydrogen

Aerobic Respiration Pathway -lots of chemical reactions –controlled by enzymes Important patterns: *energy released –> captured by ADP to make ATP *energized H released ->captured by NAD to make NADH & H+ or captured by FAD to make FADH2 NAD is like catcher’s mitt– catches fastball/high energy H FAD is like fielder’s mitt – catches slower ball/lower energy H *when C atom is lost, it is released as CO2

Aerobic Respiration Respiration in the presence of free oxygen, resulting in the complete oxidation of glucose to carbon dioxide and water as well as the release of a net of 36 ATP’s.

contains energy (potential) in chemical bonds Potato chip = fuel!!! contains energy (potential) in chemical bonds Burn chip – releases energy in form of light/heat can use that energy to do work For our bodies to do work (life processes), can’t use energy in form of heat/light … living things need energy in form of ATP ATP is the ultimate form of energy for living things! ADP = adenosine diphosphate ATP = adenosine triphosphate Gain Energized phosphate lose Energized phosphate

Aerobic Respiratory Pathway Four main parts (reactions). 1. Glycolysis (splitting of glucose) a. cytoplasm, just outside of mitochondria. 2. Pyruvic Acid breakdown a. migration from cytoplasm to

Aerobic Respiratory Pathway 3. Krebs Cycle a. mitochondria 4. Electron Transport Chain (ETC) a. mitochondria

1. Glycolysis Occurs in the cytoplasm just outside of mitochondria. Two phases: A. Energy investment phase a. 2 ATP activation energy B. Energy yielding phase a. 4 ATP produced

1. Glycolysis A. Energy Investment Phase: C-C-C-C-C-C C-C-C Glucose (6C) (2 - 3C) 2 ATP - used 0 ATP - produced 0 NADH & H+ - produced 2ATP 2ADP+ P 2

1. Glycolysis B. Energy Yielding Phase p-C-C-C C-C-C-p C-C-C C-C-C PGAL (PYR) (2 - 3C) Pyruvate (2 - 3C) or Pyruvic Acid (PYR) 0 ATP - used 4 ATP - produced 2 NADH & H+ - produced 4ATP 4ADP+4 P

1. Glycolysis Total Net Yield 2 - 3C-Pyruvic acid (Pyruvate) 2 – ATP (Stored Chemical Energy) (4 ATP produced-2 used as Activation Energy) 2 – NADH & H+

Glycolysis

Glycolysis

2. Pyruvic Acid Breakdown Occurs when Oxygen is present (aerobic). 2 Pyruvic Acid (3C) molecules are transported through the mitochondria membrane and is converted to 2 Acetyl CoA (2C) molecules. Cytoplasm C 2 Pyruvic 2 CO2 2 Acetyl CoA C-C 2NADH & H+ 2 NAD+ Matrix

2. Pyruvic Acid Breakdown End Products: 2 – NADH2 2 - CO2 (Released as waste) 2 - Acetyl CoA (2C) *Enters Kreb Cycle

Pyruvic Acid Breakdown (PAB)

Pyruvic Acid Breakdown

3. Krebs Cycle (Citric Acid Cycle) Location: mitochondria Acetyl CoA (2C) bonds to Oxalacetic acid (4C - OAA) to make Citric acid (6C). It takes 2 turns of the krebs cycle to oxidize 1 glucose molecule. Mitochondrial Matrix

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

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

Krebs Cycle

3. Krebs Cycle (Citric Acid Cycle) Total net yield (2 turns of krebs cycle) 1. 2 - ATP 2. 6 – NADH & H+ 3. 2 - FADH2 4. 4 - CO2

4. Electron Transport Chain (ETC) Location: mitochondria. Uses ETC and ATP Synthase (enzyme) to make ATP. ETC pumps H+ (protons) across innermembrane. Inner Mitochondrial Membrane

4. Electron Transport Chain (ETC) Inner membrane space Matrix Cristae Outer membrane Inner membrane

4. Electron Transport Chain (ETC) All NADH & H+ and FADH2 converted to ATP during this stage of cellular respiration. Each NADH & H+ converts to 3 ATP. Each FADH2 converts to 2 ATP (enters the ETC at a lower level than NADH & H+).

4. ETC and Chemiosmosis for NADH ATP Synthase 1H+ 2H+ 3H+ higher H+ concentration H+ ADP + lower H+ (Proton (H+) Pumping) P E T C NAD+ 2H+ + 1/2O2 H2O Intermembrane Space Matrix Inner Mitochondrial Membrane H ion gradient to gen atp

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

Electron Transport Chain NADH – NAD (recycled) ½ O2 + 2H+ 2 e’s instead of H +H

TOTAL ATP YIELD 1. 04 ATP - Phosphorylation 2. 34 ATP - ETC & oxidative phosphorylation 38 ATP - TOTAL YIELD ATP

Eukaryotes (Have Membranes) Total ATP Yield 02 ATP - glycolysis (substrate-level phosphorylation) 04 ATP - converted from 2 NADH – glycolysis 06 ATP - converted from 2 NADH – pyruvic acid breakdown phase 02 ATP - Krebs cycle (substrate-level phosphorylation) 18 ATP - converted from 6 NADH - Krebs cycle 04 ATP - converted from 2 FADH2 - Krebs cycle 36 ATP - TOTAL

Maximum ATP Yield for Cellular Respiration (Eukaryotes) Glucose Glycolysis 2ATP 4ATP 6ATP 18ATP 4ATP 2ATP 2 ATP (substrate-level phosphorylation) 2NADH 6NADH Krebs Cycle 2FADH2 2 Pyruvate 2 Acetyl CoA ETC and Oxidative Phosphorylation Cytosol Mitochondria 36 ATP (maximum per glucose)

Prokaryotes (Lack Membranes) Total ATP Yield 02 ATP - glycolysis (substrate-level phosphorylation) 06 ATP - converted from 2 NADH - glycolysis 06 ATP - converted from 2 NADH – pyruvic acid breakdown phase 02 ATP - Krebs cycle (substrate-level phosphorylation) 18 ATP - converted from 6 NADH - Krebs cycle 04 ATP - converted from 2 FADH2 - Krebs cycle 38 ATP - TOTAL

Question: In addition to glucose, what other food molecules are used in Cellular Respiration?

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

Fermentation/Anaerobic Respiration Occurs in cytoplasm when “NO Oxygen” is present (called anaerobic). Remember: glycolysis is part of fermentation. Two Types: 1. Alcohol Fermentation 2. Lactic Acid Fermentation

Alcohol Fermentation Plants and Fungi  beer and wine 2ATP C P 2NADH C 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 - Ethanol’s

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

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

THE END!!