CELLULAR RESPIRATION How Cells Release Energy

Aerobic Cellular Respiration 1. Glycolysis 4. Electron Transport System 3. Krebs Cycle Anaerobic Cellular Respiration 1. Glycolysis 2. Fermentation Cellular Respiration

Anaerobic Cellular Respiration 2. Fermentation 1. Glycolysis

(Sugar Splitting) C 6 H 12 O 6 Glucose 2 NAD+2 NADH 2 ATP2 ADP Takes place in the cytoplasm of all cells Pyruvate

2. Fermentation Alcoholic Fermentation Pyruvate AlcoholCO 2 2 NADH2 NAD+ The Significance of fermentation is to regenerate NAD+ from NADH for its continuous role in glycolysis +

2. Fermentation Lactic Acid Fermentation Pyruvate 2 NADH2 NAD+ The Significance of fermentation is to regenerate NAD+ from NADH for its continuous role in glycolysis Lactic acid

Fermentation does NOT produce additional ATP The Significance of fermentation is to regenerate NAD+ from NADH for its continuous role in glycolysis During anaerobic cellular respiration only 2 ATP are produced from one initial glucose molecule

Aerobic Cellular Respiration 1. Glycolysis 4. Electron Transport System 3. Krebs Cycle 3. Krebs Cycle: Step a 3. Krebs Cycle: Step b

1. Glycolysis (Sugar Splitting) C 6 H 12 O 6 Glucose 2 NAD+2 NADH 2 ATP2 ADP Takes place in the cytoplasm of all cells Pyruvate

The output of Glycolysis is: 2 ATP 2 NADH

The 2 pyruvates produced by glycolysis in the cytoplasm are transported into the mitochondrion to continue aerobic cellular respiration in Krebs cycle

1 st pyruvate 1 CO2 Acetyl group + CoA Acetyl-CoA 3. Krebs Cycle Takes place in the mitochondrion Step a 1 NADH

2 nd pyruvate 1 CO2 Acetyl group + CoA Acetyl-CoA 3. Krebs Cycle Takes place in the mitochondrion Step a 1 NADH

The output of Krebs Cycle step a is: 2 CO2 2 NADH

3. Krebs Cycle Step b 1 st Acetyl-CoA CoA + 4-C- compound 6-C-Compound 2 CO2 1 ATP 3 NADH 1 FADH2

3. Krebs Cycle Step b 2 nd Acetyl-CoA CoA + 4-C- compound 6-C-Compound 2 CO2 1 ATP 3 NADH 1 FADH2

The output of Krebs Cycle step b is: 2 ATP 4 CO2 6 NADH 2 FADH2

The output of Krebs Cycle both steps is: 2 ATP 6 CO2 8 NADH 2 FADH2 The output of Krebs Cycle step b is: 2 ATP 4 CO2 6 NADH 2 FADH2 The output of Krebs Cycle step a is: 2 CO2 2 NADH

Summary of energy harvest GLYCOLYSIS 2 ATP 2 NADH Krebs Cycle: 2 ATP 6 CO2 8 NADH 2 FADH2 4 ATP can be used for cellular work 6 CO2 are released Raw materials for electron transport system: 10 NADH 2 FADH2

An Overview of the Electron Transport System

The Electron Transport System 1. NADH and FADH2 pass electrons to the first protein in the electron transport system (ETS). 2. Electrons pass from energy carrier to the next. 3. With each transfer, energy is released 4. This energy is used to pump hydrogen ions into the outer compartment of the mitochondrion.

5. Hydrogen ions build up in the outer compartment (higher concentration of H+ in the outer compartment than in the matrix).

6. Hydrogen ions flow back across the membrane through an enzyme (ATP synthase) that synthesizes ATP 7. The last protein in the ETS finally passes electrons to oxygen along with hydrogen ions, generating water.

The Electron Transport System

Electron Transport System Most of ATP is produced during ETS ETS produces 32 ATP

The Overall Equation of CR C 6 H 12 O O 2 6 CO H 2 O + 36 ATP + Heat