photosynthesis

Question 1

word equation for photosynthesis

Answer 1

carbon dioxide + water –> (light) makes oxygen and glucose

Question 2

balanced symbol equation for photosynthesis

Answer 2

6CO2 + 6H2O -> C6H12O6 + 6O2

Question 3

what type of chemical reaction is photosynthesis

Answer 3

endothermic -> requires energy
in this case: light energy

Question 4

function of thin and broad leaves

Answer 4

large SA for light absorption and short diffusion pathway for gases

Question 5

function of palisade cells being long and thin

Answer 5

maximas light absorption
more can fit in a leaf

Question 6

function of many chloroplasts

Answer 6

increase the amount of chlorophyll and therefore the amount of light absorbed

Question 7

function of the spongey mesophyll containing air spaces

Answer 7

rapid diffusion of gases in and out
short diffusion pathway

Question 8

function of stomata being surrounded by guard cells

Answer 8

can control water loss and gas exchange

Question 9

function of network of vascular tissue in veins

Answer 9

provides water from roots and transports sugras from leaves to root

Question 10

3 factors affecting rate of photosynthesis

Answer 10

light intensity, temperature, carbon dioxide concentration

Question 11

how do you know if photosynthesis in a plant has taken place

Answer 11

add iodine solution to test for starch, because glucose produced in photosynthesis is stored as starch

Question 12

RP: effect of light on starch production. why do we use a plant which has been kept in the dark for 24 hours?

Answer 12

to get rid of any starch which is already present in the leaves before the experiment. starch would be converted into glucose for respiration

Question 13

RP: effect of light on starch production
what would be a suitable control experiment?

Answer 13

a plant which has been left in the dark -to show that light is needed for photosynthesis

Question 14

RP: effect of light on starch production.
why do we boil the leaf at the start?

Answer 14

kill leaf and stop it from photosynthesising

Question 15

RP: effect of light on starch production
purpose of placing leaf into boiling ethanol

Answer 15

extract chlorophyll from leaf so results from starch test are more visible

Question 16

RP: effect of light on starch production.
why did you soak leaf in hot water after ethanol

Answer 16

soften the leaf so it can be spread out on tile

Question 17

factors which affect rate of photosynthesis

Answer 17

light intensity, CO2 concentration and temperature

Question 18

when would light be a limiting factor

Answer 18

at night

Question 19

how does temperature affect rate of photosynthesis

Answer 19

particles gain kinetic energy creating more enzyme substrate complexes.

Question 20

what happens once the optimum temperature is reached

Answer 20

enzymes begin to denature and their active sight loses its complimentary shape to the substrate, fewer enzyme substrate complexes. rate of photosynthesis decreases

Question 21

how does light intensity affect rate of photosynthesis

Answer 21

higher the light intensity, higher the rate of photosynthesis but only up to a certain point. after certain point, light is no longer a limiting factor

Question 22

increase in CO2 concentration causes what

Answer 22

rate of photosynthesis to increase

Question 23

methods of controlling limited factors (light, CO2, temperature)

Answer 23

raising CO2: paraffin burner or burn fuel
temperature: thermostat
light int: light with timer, lamps which emit correct wave length of llight
suspending roots in water

Question 24

errors and improvements in RP 6 - effect of light int on rate of photosynthesis

Answer 24

bubbles may be diff sizes - use gas syringe
may count number of bubbles incorrectly - film it and watch it again and recount
lamp may emit heat - use an LED lamp or one which doesnt emit heat

Question 25

whats the square law

Answer 25

Light intensity is = to 1/distanced squared (m)

Question 26

use of glucose in plants

Answer 26

-converted into fats and oils for energy storage
-combined with nitrates in the soil for amino acids and then proteins
-converted into sucrose for transport around the plant
-used in respiration to release energy for cell

Question 27

use of many glucose molecules joined together

Answer 27

-cellulose for strength in cell walls
-starch for storage (insoluble, won’t affect osmosis in cells)

Question 28

how is the palisade layer adapted for photosynthesis

Answer 28

packed with many chloroplasts to absorb as much light for photosynthesis

Question 29

why is light needed for photosynthesis

Answer 29

provides energy
light energy turns into chemical energy

Question 30

uses of sugar in plants

Answer 30

-converted into glucose to form starch for storage
-converted into fat for energy storage
-provides chemical energy for respiration
-used to produce cellulose to strengthen cell walls
-combined with nitrate ions absorbed from the soil to produce amino acids for protein synthesis

Question 31

what happens when sugar is combined with nitrate ions

Answer 31

amino acid is produced for protein synthesis