What is Cellular Respiration?

• When organisms release the _________ stored in carbohydrates and other food molecules

energy

Sucrose: A disaccharideGlucose Fructose

Monosaccharides

Aerobic Respiration

1. Occurs when Oxygen is present

2. Many ATP Molecules made

Anaerobic Respiration

1. Occurs when no Oxygen is present

2. Very little ATP made

3. Two basic types:a. Fermentation:

Alcohol and CO2 produced

b. Lactic Acid

What did Krebs and Chance Discover in their Research?• Enjoy this video clip, and jot down a

summary of Krebs’ and Chance’s research.

• Pay attention to the significance of both scientist’s discoveries.

Label the parts of the mitochondrion

Inner membrane

Outer membrane

Cristae

Matrix

Inter-membrane

space

3 stages of Cellular Respiration

1. Glycolysis: • Occurs in the cytoplasm

• No O2 required

2. Krebs Cycle:• Occurs in the mitochondrion

3. Electron Transport Chain• Requires O2

““Glyco” “lysis” literally means Glyco” “lysis” literally means “sugar” “splitting”“sugar” “splitting”

ATP ATP

P P

ADP ADP

ATP = -2= -2

P

P

Glycolysis takes place in the Glycolysis takes place in the cytoplasmcytoplasm

PP

NAD+

NAD+NADH

NADH

NADH = +2= +2

P

P

Glycolysis takes place in the Glycolysis takes place in the cytoplasmcytoplasm

P

P

ADP

ADP

ATP

ATP

ATP = +2= +2

Glycolysis takes place in the Glycolysis takes place in the cytoplasmcytoplasm

P

P

ADP

ADP

ATP

ATP

ATP = +2= +2

PyruvatePyruvate

What is the net gain of energy in

Glycolysis?

• ATP = + 2

• NADH = + 2

The Krebs Cycle takes place in The Krebs Cycle takes place in the Matrix of the Mitochondrionthe Matrix of the Mitochondrion

NAD+

NAD+NADH

NADH

CoA

CoA

Acetyl CoA

The Krebs Cycle takes place in The Krebs Cycle takes place in the Matrix of the Mitochondrionthe Matrix of the Mitochondrion

CoA Citrate

The Krebs Cycle takes place in The Krebs Cycle takes place in the Mitochondrionthe Mitochondrion

NAD+NADH

The Krebs Cycle takes place in The Krebs Cycle takes place in the Mitochondrionthe Mitochondrion

NAD+NADH

The Krebs Cycle takes place in The Krebs Cycle takes place in the Mitochondrionthe Mitochondrion

P

ADPATP

NADHNAD+

The Krebs Cycle takes place in The Krebs Cycle takes place in the Mitochondrionthe Mitochondrion

FADHFADH2

What is gained and lost for each pyruvate molecule?

• What is lost during the Krebs Cycle?– A Carbon atom must

be lost– It is lost in the form of

Carbon Dioxide

– There are 3 CO2 molecules lost

• What is gained during the Krebs Cycle?– 4 NADH molecules are

made.

– 1 FADH2 molecule is made

– 1 ATP molecule is made

What is gained per glucose molecule?

NADH = +4

ATP = +1

FADH2 = +1

• But there were two molecules of Acetyl CoA (per glucose) that went into the Krebs Cycle…

• How many would actually be produced in this case?

+8

+2

+2

Where is the energy?

• So far, most of the usable energy from the original glucose molecule is stored as electrons in and

• Where will most of the ATP be made?

The Electron Transport Chain

NADH FADH2

Where is the Electron Transport Where is the Electron Transport Chain?Chain?

Inside the mitochondrion.

Folds of the inner membrane known as cristae.

Many ATP molecules willbe produced in these

Electron Transport Chains

How much ATP can each How much ATP can each electron carrier make?electron carrier make?

FADH2

NADH

FADH2

FADH2

ATP

ATP

ATPATP

ATP

After electrons travel through the ETC, Oxygen is the final electron acceptor. Electrons, and two Hydrogen

ions attach to the oxygen, and H2O is formed.

Hydrogen ions pump from the matrix to the inter- membrane space, using the energy from the

electrons.

The diffusion of H+ ions through the enzyme, ATP synthase makes ATP

C6H12O6ATP

C6H12O6 CO2 H2O ATP

C6H12O6 CO2 H2OO2 ATP+ + +

• With a neighbor, fill in the steps in this cycle of Photosynthesis and Respiration.

• We will check your answers when you are done!

Photosynthesis and Respiration