Mitochondria & Cell Respiration

powerhouse of cell, site of cellular respiration

First Law of Thermodynamics

energy cannot be created NOR destroyed BUT it can be transformed

Second Law of Thermodynamics

one usable form of energy cannot be completely converted to another usable form

Chemical Equation for Cellular Respiration

C6H12O6 + 6O2 → 6CO2 + 6H2O + 32 ATP

What are the stages of CR?

• Glycolysis

  • Pyruvate Oxidation

• Citric Acid Cycle

• Oxidative Phosphorylation

Gylcolysis

breaks down glucose into 2 molecules of pyruvate

Pyruvate Oxidation

converts pyruvate into Acetyl CoA

Citric Acid Cycle

completes the breakdown of glucose

Oxidative Phosphorylation

ATP synthesis through electron transport and chemiosmosis

Electron Transport Chain (ETC)

uses electrons from NADH & FADH to make a proton gradient across the inner mitochondrial membrane

Chemiosmosis

ATP Synthase uses the proton gradient to synthesize ATP

Where does glycolysis occur?

cytoplasm - cytosol

Where does pyruvate oxidation occur?

enters mitochondrial matrix

Where does citric acid cycle occur?

mitochondrial matrix

Where does ETC occur?

inner mitochondrial membrane

How many direct ATPs does glycolysis make?

2

How many direct ATPs does citric acid cycle make?

2

How many direct ATPs does ETC make?

26 - 28

Glycolysis contribution to ETC

2 NADH = 5 ATP

Pyruvate Oxidation contribution to ETC

2 NADH = 5 ATP

Citric Acid Cycle contribution to ETC

6 NADH = 15 ATP

2 FADH2 = 3 ATP

ETC contribution to ETC

USES:

10 NADH

2 FADH2