Cellular Respiration

Respiration

Catabolic process that occurs in all cells. It can be aerobic or anaerobic.

What is being oxidized?

C6H12O6 → CO2

What is being reduced?

O2 → H2O

Electron carriers

NADH and FADH2

1st Step

Glycolysis

Where does Glycolysis occur?

Cytoplasm

1st phase of Glycolysis

Energy investment

What type of reaction is the energy investment phase?

endergonic → uses ATP

2nd phase of Glycolysis

Energy payoff

What type of reaction is the Energy payoff phase?

exergonic → makes ATP

What goes “in” glycolysis?

2 ATP

What comes out of Glycolysis?

• 4 ATP

• 2 NADH

What results from 1 glucose (6 C) in Glycolysis?

2 Pyruvate (3 C)

What type of process is Glycolysis?

Anaerobic (does not require O2)

2nd Step

Pyruvate Oxidization

Where does Pyruvate Oxidation occur?

Mitochondria

How many times does Pyruvate Oxidation occur?

2 times per glucose

How much ATP is needed and produced during Pyruvate Oxidation?

None used or produced

What comes “out” of pyruvate oxidation for 1 glucose?

• 2 NADH

• 2 CO2

3rd step

Citrus Acid Cycle

Where does the Citrus Acid Cycle take place?

mitochondrial matrix

What does the Citrus Acid Cycle start with?

Acetyl - CoA and oxaloacetate

How many steps are in the Citrus Acid Cycle?

8

What is Acetyl-CoA oxidized to?

CO2

What does the first turn of the CAC generate?

• 2 CO2

• 1 ATP

• 3 NADH

• 1 FADH2

What does the 2nd turn of the CAC generate?

• 4 CO2

• 2 ATP

• 6 NADH

• 2 FADH2

What comes “out” of the Citrus Acid Cycle?

• 2 ATP

• 6 NADH

• 2 FADH2

• 4 CO2

4th and 5th step

Oxidative Phosphorylation(ETC) and Chemiosmosis

How is a proton gradient created?

from the energy stored in NADH and FADH2

What is Chemiosmosis?

Proton diffusion across inner membrane and drives ATP synthesis

Where does the ETC occur?

inner mitochondrial matrix

Where do the electron carriers come from?

through ETC → O2

How is the H+ gradient formed?

Energy used via active transport

Intermembrane space

[H+] > matrix [H+]

What is the terminal electron acceptor?

O2

Point of ETC

to minimize E lost as heat - maximize E saved at H+ gradient

Chemiosmosis

E coupling mechanism used to synthesize ATP and to convert potential E to potential E in ATP

ATP made by…

ATP synthase

ATP synthase

Protein complex, H+ diffuses through exergonic and causes rotation. E for ATP synthesis