C1.3 Photosynthesis

Question 1

Plants use the energy of sunlight to make organic molecules from water and CO2, which makes them…

Answer 1

photoautotrophs

Question 2

Heterotroph

Answer 2

A non-photosynthetic or chemosynthetic organism that obtains its food from other organism

Question 3

What supplies most of the chemical energy needed for life processes in ecosystems?

Answer 3

The energy transformation of light to chemical

Question 4

Equation of photosynthesis

Answer 4

6H2O + 6CO2 = C6H12O6 + 6O2, carbon dioxide + water (light) –> glucose + oxygen

Question 5

A waste product of photosynthesis

Answer 5

Oxygen, diffused through the stomata (pores), comes from the splitting of water

Question 6

Photosynthesis and electromagnetic spectrum

Answer 6

Photosynthesis happens within the visible range of the spectrum (including light) -> pigments are chemical molecules that absorb light (red and blue absorbed most effectively, green reflected) -> plant pigments can be extracted

Question 7

Chromatography + Rf values

Answer 7

Rf = distance run by pigment / distance run by solvent

Question 8

Absorption of specific wavelengths of light by photosynthetic pigments

Answer 8

Absorption of light causes excitation of electrons within pigment molecule which converts light energy to chemical energy, only some wavelengths are absorbed due to green pigment in chlorophyll, longer wavelengths = less energy

Question 9

Absorption and action spectra

Answer 9

Absorption spectrum = absorption of light by pigment at each wavelength, action spectrum = rate of photosynthesis at each wavelength

Question 10

Carbon dioxide enrichment experiments

Answer 10

A way to predict future rates of photosynthesis and plant growth = increasing CO2 concentration, conducted in “free air” –> “FACE” free air carbon enrichment