Photosynthesis (B6.1)

Question 1

photosynthesis definition

Answer 1

the process by which plants make carbohydrates from raw materials using energy from light

Question 2

chlorophyll (3 points)

Answer 2

• pigment that makes plants green
• found inside chloroplasts
• chlorophyll transfers light energy into chemical energy in molecules, for the synthesis of carbohydrates

Question 3

glucose (4 points)

Answer 3

• make energy (stored as APT)
• very reactive (cannot travel from leaves) –> so gets converted into sucrose (disaccharide)
• sucrose travels through network of tunnels called phloem
• excess glucose or sucrose –> turns into starch (if glucose is stored in leaves, then its stored as starch, otherwise it can be converted into celluose)

Question 4

Factors of photosynthesis (4 points)

Answer 4

• Light
• CO2
• temperature
• chlorophyll (the amount)

Question 5

xylem does what?

Answer 5

travels upwards only from root to leaf to transport water and minerals (xylem is made out of dead cells)

Question 6

phloem does what?

Answer 6

travels up and down through the plant, transports sucrose

Question 7

Magnesium - Source and Importance in plants

Answer 7

Source: Absorbed as Mg2 from the soil solution
Importance: Manufacture of chloroplats - Absence makes leaves turn yellow and eventually stops photosynthesis

Question 8

Nitrogen - Source and important in plants

Answer 8

Source: Absorbed as nitrate or ammonium from soil solution
Importance: Manufacture of proteins, nucleic acids, and plant hormones - absence causes poor growth, especially in leaves

Question 9

Transpiration definition (from B8)

Answer 9

Loss of water vapour from plant leaves by evaporation of water at the surfaces of the mesophyll cells followed by diffusion of water vapour through the stomata