C1.3 Photosynthesis

Question 1

Define photosynthesis

Answer 1

The production of carbon compounds in cells using light energy.

Question 2

Photosynthesis equation

Answer 2

6CO2 + 6H2O –sunlight—-> C6H12O6 +6O2

Carbon dioxide + water –light—> glucose + oxygen

Question 3

Outline the production of carbohydrates in photosynthesis (the phases)

Answer 3

1. Light energy is absorbed by chlorophyll and converted into chemical energy.
2. This energy is used to break bonds in water molecules resulting in hydrogen ions and oxygen molecules.
3. H ions needed for reduction reaction that converts CO2 to glucose.
4. O2 is a byproduct that diffuses out of the cell and into the atmosphere.

Question 4

How do organisms absorb light? (hint: specific wavelength)

Answer 4

• Photons are absorbed by pigment molecules if the energy they hold excites the electrons in the pigment molecule.
• This specific amount of energy is only supplied by a certain wavelength of light.

Question 5

Similarities and differences of absorption and action spectra

Answer 5

• Absorption spectra: a graph showing percentage of light absorbed at each wavelength by a pigment.
• Action spectra: graph showing rate of photosynthesis at each wavelength of light.

Similarities:
- x-axis is wavelength in nanometers

Differences:
- Action: y-axis is measure of relative rate of photosynthesis
- Absorption: y-axis is relative amount of light absorbed.

Question 6

Calculating Rf value

Answer 6

Distance traveled by the compound / Distance traveled by solvent front