Photosynthesis topic 2.9

Question 1

Photosynthesis

Answer 1

Photosynthesis involves the use of light energy to synthesise
organic compounds from inorganic molecules

Question 2

Light Spectrum

Answer 2

Visible light has a range of wavelengths (~ 400 – 700 nm)
* Violet has the shortest wavelength, red has the longest

Question 3

Light Absorption

Answer 3

Pigments are required for the conversion of light energy into chemical energy in photosynthetic organisms

Question 4

Chlorophyll

Answer 4

main photosynthetic pigment

Chlorophyll absorbs red light and blue light most effectively and reflects green light more than other colors

Question 5

absorption spectrum

Answer 5

indicates the wavelengths of light absorbed by each photosynthetic pigment

Question 6

action spectrum

Answer 6

indicates the overall rate of photosynthetic activity at each wavelength of light

Question 7

Light Dependent Reactions

Answer 7

Light energy is converted into chemical energy
* Light is absorbed by chlorophyll to produce ATP
* The photolysis of water forms oxygen and hydrogen

Question 8

Light Independent Reactions

Answer 8

Carbon compounds are made from the chemical energy
* ATP and hydrogen are fixed with carbon dioxide
* This results in the formation of organic molecules

Question 9

Chromatography

Answer 9

Pigments can be separated by chromatography
* Pigments are dissolved in fluid
* The fluid is passed through a static material
* Pigments are separated according to size

Question 10

Limiting Factors

Answer 10

When a process depends on more than one condition, the
rate will be limited by the factor nearest its minimum value

Question 11

Limiting factors in photosynthesis include:

Answer 11

• Temperature (influences photosynthetic enzymes)
• Light intensity (required for chlorophyll photoactivation)
• Carbon dioxide concentrations (CO2 is a core substrate)