What is Cellular Respiration? The process whereby cells convert

carbohydrates to energy in the form of ATP (energy storage molecule)

All cells undergo respiration Aerobic respiration is the most efficient

method, yielding the greatest amount of ATP per glucose molecule

Anaerobic respiration is less efficient but provides a method for getting energy (ATP) in the absence of oxygen

Aerobic Cellular Respiration Equation

C6H12O6 + 6O2 6CO2 + 6H2O + energy (glucose) (oxygen) (carbon dioxide) (water)

Does this equation look familiar?

It is the reverse of the photosynthesis equation.

Aerobic Cellular Respiration:Respiration in the Presence of

OxygenTwo Main Parts1st Part: Anaerobic Process

Glycolysis in cytoplasm

2nd Part: Aerobic ProcessesKrebs CycleElectron Transport Chainin mitochondrion

Aerobic Cellular Respiration

Three steps: 1. Glycolysis

2. Krebs Cycle

3. ETC (Electron Transport Chain)

Glycolysis

• glycolysis is an anaerobic process, meaning it does NOT require oxygen

• occurs in the cytoplasm

• glucose is broken down into pyruvate

• yields 2 molecules of ATP

2 molecules

Krebs Cycle• aerobic metabolic process,

meaning it REQUIRES oxygen

• also known as the Citric Acid Cycle

• occurs in the mitochondrion

• takes the product of glycolysis and converts it to carbon dioxide

• yields 2 molecules of ATP

6CO2

2 molecules

Electron Transport Chain

• aerobic metabolic process

• occurs in the mitochondrion

• releases the greatest amount of ATP

• yields about 34 molecules of ATP

34 molecules

Chloroplast

Mitochondria

glucose+

oxygen

carbon dioxide+

water

• photosynthesis & cellular respiration are cyclic processes• the products of one are the reactants of the other

Anaerobic Cellular Respiration:

Respiration in the Absence of Oxygen

•= Glycolysis + Fermentation

•allows cells to produce ATP WITHOUT OXYGEN

• no ETC is present (recall how many ATP molecules are created by the electron transport chain = ___ ATP)

• method used by anaerobic bacteria

• method used by organisms which ordinarily undergo aerobic respiration when there is no oxygen present

34

Glycolysis + Fermentation

• In the absence of oxygen, the product of glycolysis (pyruvate) enters into the fermentation pathway

• Two pathways (pathway is dependent on the organism)

1. Alcoholic fermentation

2. Lactic acid

Fermentation

Alcoholic Fermentation• yeast undergo alcoholic fermentation• glucose is converted to ethanol & carbon dioxide • yields 2 ATP molecules• applications

CO2 makes bread rise

brewing beer winemaking ethanol fuel

Lactic Acid Fermentation• glucose is converted to lactate• some bacteria undergo lactic acid fermentation

applications = yogurt, sauerkraut, kimchi

• muscle cells can continue to produce ATP when oxygen runs low but muscle fatigue and pain may result fast twitch muscles for

sprinting white meat in poultry

Summarize: 3-2-1

3 Steps of Aerobic Cellular Respiration

2 Types of Fermentation

1 Main Goal of Cellular Respiration