AP Biology

Unit 3 Notes: Cellular Respiration

(1) Energy in Living Things

Endergonic Process:A process that stores available energy in newly formed bonds.

Exergonic Process:A process that releases stored energy from broken bonds.

Photosynthesis & Respiration are a constant cycling of ender and exerprocesses, in order to transfer matter and energy.

(2) Cells & Organisms

All living organisms complete Cellular Respiration (except for chemosynthetic organisms).

Plants have both Chloroplasts & Mitochondria.

(3) The Mitochondrion

A double, membrane-bound organelle.

Channels = “Cristae”

Inside the Channels = “Matrix”

Membrane that makes up the Cristae = “Inner Membrane”

(4) C.Respiration Big Ideas

Chemical Potential Energy is transferred from the bonds of Glucose, to the bonds of ATP.

Glucose and Oxygen Gas react, to produce, Carbon Dioxide Gas-Water-and ATP.

(5) Stages of C.Respiration:

During Aerobic Respiration:1- Glycolysis

2- The Formation of Acetyl CoA

3- Krebs / Citric Acid Cycle

4- Oxidative Phosphorylation

During Anaerobic Respiration: 1- Glycolysis

2- Fermentation

(6) Glycolysis Details:

Location = Cytoplasm of Cell (outside Mitochondrion)

Glucose--> 2 Pyruvate + 2 ATP + 2 NADH

Start off with a 6 Carbon Glucose:Break it down into two 3 Carbon Sugars (Pyruvate / Pyruvic Acid).

Released energy stored in bonds of 2 ATP molecules.

(7) Formation of Acetyl CoA:

Location = Between the Outer + Inner Membrane of Mitochondrion

2 Pyruvate + 2 Coenzyme A --> 2 Acetyl CoA + 2 NADH

Start off with 3 Carbon Pyruvates:Break it down into 2 Carbon Acetyl CoA + Carbon Dioxide

CO2 released as a waste gas

(8) Krebs / Citric Acid Cycle:

Location = Matrix of Mitochondrion

2 Acetyl CoA + Oxaloacetate --> Oxaloacetate + 6 NADH + 2 FADH2 + 2 ATP

Start off with 2 Carbon Acetyl CoA:Combines with 4 Carbon Oxaloacetate

Citric Acid Produced (6 Carbon Sugar) --> Which turns back into Oxaloacetate to fuel the cycle.

(9) Oxidative Phosphorylation:

Location = Inner Membrane of Mitochondrion

10 NADH + 2 FADH2 + 2 O2 --> O + 10 NADH + 2 FADH2 + 26 ATP

Steps in Oxidative Phosphorylation:1- Electron Transport Chain

2- Chemiosmosis

Electron Transport Chain: Electrons + Hydrogen Ions were removed from Glucose during

Glycolysis. Electrons + Hydrogen Ions are carried through NADH and

FADH2 molecules in the Inner Membrane of the Cristae Gradient formed (driving movement of Electrons) Oxygen Combines with Hydrogen Ions --> Water Produced

Chemiosmosis: Additional Hydrogen Ions pumped through ATP Synthase Matrix --> Inner Membrane ATP Produced

(10) Aerobic vs Anaerobic:

Aerobic = ATP made with Oxygen Gas

Anaerobic Respiration:Emergency way to make ATP without Oxygen Gas.

Electron Transport Chain has no Oxygen Acceptor.

Citric Acid + Acetyl CoA cycles stop with nowhere to send electrons.

Still does Glycolysis (but only produces 2 ATP).

Pyruvate takes Electrons from NADH --> Lactic Acid / Ethanol produced.

(11) Porque??? (Why?)

Didn’t we make ATP in Photosynthesis?Yes, but only 1 molecule, and it was used in the Calvin Cycle.

C.Respiration produces a lot more ATP.

How much ATP is made?30 molecules total in Aerobic Respiration

2 molecules total in Anaerobic Respiration

(12) Photosynthesis & C.Respiration

Both…Rely on Proton Gradient to make ATP thru ATP Synthase.

Use an Electron Gradient in membrane (E.Transport Chain).

The Krebs & Calvin Cycles are a series of reactions used…- To release stored energy- To produce a new energy storing molecule- To regenerate molecules needed