photosynthesis

Question 1

what is light energy absorbed by?

Answer 1

chlorophyll

Question 2

what kingdoms does photosynthesis occur in?

Answer 2

plants, and some bacteria/protoctista too

Question 3

word equation for photosynthesis?

Answer 3

carbon dioxide + water —> glucose + oxygen

Question 4

balanced chemical equation for photosynthesis?

Answer 4

6CO2 + 6H2O —> C6H12O6 + 6O2

Question 5

what are nitrates (NO3 -) used for in plants?

Answer 5

they’re required to make amino acids (and so proteins), and nucleic acids (DNA and RNA)

Question 6

what is magnesium (Mg) used for in plants?

Answer 6

required to make chlorophyll

Question 7

what are phosphates (PO4 3-) used for in plants?

Answer 7

required to make nucleic acids (DNA and RNA); is part of cell membrane

Question 8

symptoms of nitrates deficiency in plants?

Answer 8

stunted growth

Question 9

symptoms of magnesium deficiency in plants?

Answer 9

yellow leaves

Question 10

symptoms of phosphates deficiency in plants?

Answer 10

poor root growth; purple younger leaves

Question 11

what is the limiting factor?

Answer 11

the factor which is in shortest supply

Question 12

what are the factors affecting photosynthesis?

Answer 12

1. the availability of the substrates for the reaction - carbon dioxide & water
2. energy available to allow the reaction to occur - light intensity
3. kinetic energy available to move substrate and enzyme molecules - increasing temperature increases kinetic energy

Question 13

what are the adaptations of the upper epidermis?

Answer 13

it’s transparent, allowing light to penetrate to the mesophyll

Question 14

how is the leaf specialised for photosynthesis?

Answer 14

-large surface area, thin, to maximise absorption of sunlight by photosynthetic cells
-this also increases number of stomata, so CO2 can diffuse quicker

Question 15

what are palisade cells like?

Answer 15

-long, thin, tightly packed
-contain large numbers of chloroplasts
-this maximises absorption of sunlight energy
-palisade mesophyll is main site of photosynthesis

Question 16

what do stomata do

Answer 16

-allow gases to diffuse into air spaces of leaf
-this provides a short diffusion distance for CO2

Question 17

what’s the xylem

Answer 17

-transports water (absorbed in roots) to leaves
-this then provides short distance for water to diffuse into photosynthesising cells

Question 18

what’s the phloem vessels do

Answer 18

transport sugars made in photosynthesis to other parts of the plant