Cellular Respiration

Adenosine Triphosphate

• Universal energy carrier of the cell– Active transport

– Reproduction

– Movement

– Muscle contractions

– Protein synthesis

• Hydrolysis of ATPATP + H2O ADP + Pi + Energy

• Energy used to produce heat & drive processes

Cellular Respiration

1C6H12O6 + 6O2 6CO2 + 6H2O + 36 ATP

• Primarily in mitochondria

• Chemical energy in glucose converted to ATP

• Necessary for both consumers (heterotrophs) and producers (autotrophs)

Glycolysis• Start: Glucose (6-

carbon molecule)• 2ATP energizes the

glucose– Phosphate breaks

from ATP

• Glucose (6C) broken into two Pyruvates (3C)

• Finish:Two pyruvates

4 ATPs

NADH (H carriers)

ATPATPATP

ATPPyruvate

Pyruvate

NADH NADH

Glycolysis Summary

Kreb’s Cycle (Citric Acid Cycle)

• Step 1: Pyruvate broken down

– Pyruvate (3C) is split into Acetic Acid (2C) and CO2

– More NADH created

CO2 CO2

Acetic acid Acetic acid

• Step 2: Coenzyme A– Acetic Acid (2C) combines with coenzyme A to

create Acetyl-CoA (2C)

• Step 3: Citric Acid formed– Acetyl-CoA (2C) binds with 4C molecule (from previous

Kreb’s cycle)– Citric Acid (6C) created

• Step 4: Citric Acid broken down– Citric Acid (6C) broken into 5C molecule– CO2 waste created– More NADH created

CO2 CO2

Citric acid Citric acid5C molecule 5C molecule

• Step 5: 5C molecule broken down– 5C molecule broken down into 4C molecule– CO2 waste created– More NADH created– ATP created

5C molecule 5C molecule

ATP ATP

CO2 CO2

4C molecule 4C molecule

• Step 6: 4C molecule rearranged

– Enzymes rearrange the 4C molecule

– More NADH, FADH2 created

– 4C molecule restarts the Kreb’s cycle when bonded with Acetyl-CoA

4C molecule 4C molecule

Acetyl coA Acetyl coA

Citric acid Citric acid

Kreb’s Summary

• 2 Pyruvate molecules (from glycolysis) create:– 6CO2, 2ATP, 8NADH, 2FADH2

ATPATPATP

ATPPyruvate

Pyruvate

Glycolysis: net gain of 2ATP

CO2 CO2

Acetic acid Acetic acid

Kreb’s Cycle (Citric Acid Cycle)

Kreb’s Cycle (Citric Acid Cycle)

CO2 CO2

Citric acid Citric acid5C molecule 5C molecule

Kreb’s Cycle (Citric Acid Cycle)

5C molecule 5C molecule

ATP ATP

CO2 CO2

4C molecule 4C molecule

Kreb’s Cycle (Citric Acid Cycle)

Electron Transport Chain

• Step 1: Electrons removed– Electrons removed from NADH and FADH2

• Step 2: Hydrogen Ions Transported– Proteins pump H+ ions across inner membrane of

mitochondria– H+ ions accumulate

H+

H+

H+ H+

H+

• Step 3: ATP produced– H+ ions diffuse through protein channels to bind

ADP + Pi

– 34 ATP created

H+H+

H+

H+

ATP

ATPATP

ATP

• Step 4: Water created

– Oxygen binds with H+ ions to create 6H2O as a waste

H+

H+

H+

O

O

O

H+

H2 O

H2 O

Your essay question on the next test!

Trace the flow of energy, including ATP, from the sun to your muscles, after eating a green leaf salad.