CELLULAR RESPIRATION

WHO DOES CELLULAR RESPIRATION?AnimalsHumansPlants/Algae

Basically any organism with nuclei & mitochondria

So what other organisms have mitochondria?

Mitochondria: organelle in cell that functions in production of energy

WHAT IS CELLULAR RESPIRATION?

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

Exothermic reactionOccurs in the mitochondriaEnzymes are necessary for reaction

to occurWhere have you heard enzymes

before?

WHY DO THEY DO IT?

To release energy stored in food

To convert the energy into a different form of energy that the organism’s cell(s) can use

2 TYPES OF RESPIRATION

Aerobic: oxygen is present; large amounts of ATP are produced

Anaerobic: absence of oxygen; less amounts of ATP are produced

AEROBIC RESPIRATION: 3 STEPS

Glycolysis: the breakdown of glucose (C6H12O6) into pyruvate (3 carbon compound); 2 ATPs formed

Kreb’s Cycle (Citric Acid Cycle): converts pyruvate into CO2; 2 ATPs formed

Electron Transport Chain: uses NADH & FADH2 (just carrier molecules) to form 32 ATPs & water

CELLULAR RESPIRATION

GLYCOLYSIS

Means “splitting of sugar”Breakdown of glucose into

pyruvateOccurs in cytoplasm of cellSince it happens in the

cytoplasm, what does this mean?Produces 2 ATP molecules

KREB’S CYCLE

Converts pyruvate into CO2

Occurs in the mitochondriaProduces 2 ATP molecules +

NADH + FADH2 + CO2

Remember NADH and FADH2 are just carrier molecules.

ELECTRON TRANSPORT CHAIN

Uses NADH & FADH2 to form ATP & H2O

Occurs in mitochondrial membrane

Produces 32 ATP molecules & water

END RESULT: 36 ATP molecules

ANAEROBIC CELLULAR RESPIRATION

2 types:

Alcohol FermentationLactic Acid Fermentation

Fermentation: the anaerobic (no oxygen) conversion of sugar to carbon dioxide

ALCOHOL FERMENTATION

2 Step Process:

Glycolysis [produces 2 ATP molecules]

Pyruvate + NADH Ethanol (alcohol) + NAD+ + CO2 [produces NO energy]

Final energy total: 2 ATP molecules from 1 molecule of glucose

ALCOHOL FERMENTATION CONT.

Exhibited by yeast in baking bread

Used to make wine or beer

LACTIC ACID FERMENTATION

2 Step Process:

Glycolysis [produces 2 ATP molecules]

Pyruvate + NADH Lactic Acid + NAD+ [produces NO energy]

Final energy total: 2 ATP molecules from 1 molecule of glucose

LACTIC FERMENTATION CONT.

Exhibited in the souring of milkOccurs in muscle cells when they

run out of oxygen

LACTIC FERMENTATION IN MUSCLES

When muscles are exercised & there is not enough O2 in the cells, the cells must get energy another way- lactic

acid fermentation.

The lactic acid, if not released, builds up in the muscles & causes fatigue & soreness.

After time, the lactic acid is removed from the

muscles, taken to the liver & recycled back into

pyruvate.