Anaerobic Cellular Respiration

Without oxygen

2 Steps

1. Glycolysis splits sugar and produces 2 net ATP

2. Fermentation replenishes needed molceules

Fermentation

• GOAL: break down NADH to renew NAD+ needed to continue cellular respiration

• Makes NO ATP• Second stage of anaerobic respiration• Makes carbon dioxide and 2 Carbon

byproduct in the process (alcohol or lactic acid is the 2 C byproduct depending on what organism does this.

Two types of fermentation

• Lactic acid in animals: produces lactic acid and this leads to fatigue.

• Alcohol fermentation in other organisms: produces alcohol that is used in making bread, wine, beer, and other foods.

Photorespiration• Without sufficient levels

of carbon dioxide oxygen binds to RuBP and wastes all of the effort of photosynthesis.

• Involves:– Chloroplast– Peroxisomes– Mitochondrion

– Uses oxygen instead of CO2

– NO SUGAR MADE

C3 plants

Most plants are C3 plants. They take in Carbon dioxide throughout the daytime as needed as their stomata are open unless under extreme conditions.

Unfortunately: transpiration is a large problem as water vapor escapes from the stomata.

C4 plants

• This type of plant can’t afford to leave its stomata open so often.

• They convert Carbon dioxide to a 4 Carbon organic molecule. The 4 C molecule allows carbon dioxide to be moved to the bundle sheath cells where it will be used to make sugars.

• They only open their stomata periodically to take in large amounts of carbon dioxide in a short period of time, so there is less transpiration.

C4 plants

CAM plants

• These plants bring in the carbon dioxide at night and store it as a 4C sugar. They can then break it down during the day when light is present to produce the ATP and NADPH needed for the light independent reactions.

• Stomata stay shut all day long when it is hot and the rate of transpiration is greater.

CAM Plants

Obligate vs. Facultative

• Obligate: must

• Facultative: can

• Obligate anaerobe: cow intestine

• Facultative anaerobe: us (humans)

• Obligate aerobe: only can live in the presence of oxygen (dangerous)

REDOX (reduction/oxidation reactions): Pass electrons from one

molecule to another.

• OIL RIG– Oxidation is loss– Reduction is gain

• LEO GER– Lose electrons oxidation– Gain electrons reductionREDOX: electron transport chain

Chemosynthesis

• Uses the reduction from H2S in hydrothermal vents to make sugars.

• No light: energy comes from the vents.

• Carbon dioxide is still being fixed to become a sugar, so many organisms rely on this for their food web as no photosynthesis can occur at these depths.

Hydrothermal vents

• http://www.youtube.com/watch?v=4LoiInUoRMQ– David Attenborough shows a hydrothermal

vent community

Productivity

• Net productivity = gross productivity – cellular respiration by the photosynthetic organism.

• Some sugar that is made is then used by the organism for metabolic activities.