Krebs Cycle and Electron Transport Chain

Section 9-2

Krebs Cycle

• Location: matrix of mitochondria.• First, pyruvic acid is broken down into

Acetyl Co-enzyme A and then into Citric Acid.

• CO2 is produced• Electron carriers produced: FADH2 and

NADH.• Net of 2 ATP are formed. (1 from each

pyruvic acid from glycolysis)

Section 9-2Krebs Cycle

Krebs Cycle

• Reactants:– Pyruvic Acid becomes

Acetyl Co-A becomes

Citric Acid

– NAD+ and FAD+ used

– ADP used

• Products:– CO2 produced

– NADH and FADH2 produced

– ….NET 2 ATP PRODUCED!

Electron Transport Chain• Location: cristae (inner membranes) of the

mitochondria.• The electron carriers (NADH and FADH2)

release their high energy electrons to carrier proteins.

• H+ ions move through ATP channel to generate the ATP.

• Oxygen is the final electron acceptor in the chain and combines with the H+ ions = H2O.

• Net total of 32 ATP.

Animation

Section 9-2

Electron TransportHydrogen Ion Movement

ATP Production

ATP synthase

Channel

Inner Membrane

Matrix

Intermembrane Space

Mitochondrion

ETC

ETC

• Reactants:– NADH and FADH2

release electrons and H+ ions which move through ATP synthase…

– Electrons added to H+ and O2 …

• Products:– NAD+ and FAD+

produced

– …producing ATP

– …forming H2O

NET 32 ATP

Energy and Exercise

ATP in muscles and Creatine Phosphate to generate more ATP

Lactic Acid Fermentation

CO2 and H2O C6H12O6 and O2

CC6H12O6 and O2 CO2 and H2O

6CO2 + 6H2O C6H12O6 + 6O2 6O2 + C6H12 O6 6H20 + 6CO2

Chloroplasts Mitochondria