Energy for Life: Photosynthesis, Respiration, and Fermentation

Chloroplasts

• The green oval-shaped structure that gives plants their green color.

• It is found within the cytoplasm.• It function to capture energy from the sun to

produce food (glucose) for the cell.

Photosynthesis

• The process of changing light energy into chemical energy.

• Energy is stored as food, also known as glucose.

• Photosynthesis occurs in plants and some algae.

• Plants need light energy, carbon dioxide, and water.

Photosynthesis

• This process takes place in the chloroplasts, using chlorophyll, the green pigment in plants.

• The chemical equation for photosynthesis is: 6 CO2 + 6 H2O → C6H12O6 + 6 O2

• Click on the following link to see an illustration of photosynthesis: http://www.phschool.com/science/biology_place/biocoach/photosynth/overview.html

Mitochondria• Looks like a kidney-bean shaped organelle.• It is found floating in the cytoplasm.• It functions as the “power-house” because it

changes energy stored in food compounds into a useful form of energy.

Respiration

• Using oxygen to break down glucose molecules to release energy.

• This process is also known as cellular respiration.

• There are two stages to respiration:– The 1st stage takes place in the cytoplasm.– The 2nd stage takes place in the mitochondria.

• The chemical equation for respiration is:C6H12O6 + 6O2 --> 6CO2 + 6H2O + energy

Respiration Con’t.

• Click on the link below to watch an animation about photosynthesis and respiration: http://www.sumanasinc.com/webcontent/animations/content/cellularrespiration.html

Fermentation

• The breaking down of glucose without using oxygen. Therefore this process can be described as occurring in the absence of what element? __________

• This process is also known as anaerobic respiration.

Fermentation Con’t.

• There are two types of fermentation:– Alcoholic: produces alcohol, energy, and CO2• Occurs when bread is being baked.

– Lactic-Acid: produces energy and lactic acid.• Occurs during a very fast run.