photosynthesis

Question 1

importanc of photosynthetic pigemnts

Answer 1

(pigments) absorb , light / photons

electrons , excited / raised to
higher energy level
accessory pigments pass energy
to , reaction centres / primary
pigments
primary pigments , become
oxidised / lose electrons / pass
electrons to ETC
for light dependent reaction /
photophosphorylation

Question 2

aquaitic plants

Answer 2

can absorb shorter wavelengths as some wavelengths dot reach them

Question 3

Explain why it was important that the pellet was suspended in buffer solution and why it did not contain
sucrose.

Answer 3

buffer maintains optimum ph ensuring enzymes dont denature
no sucrose as there was no need to prevent damage to chloroplasts

Question 4

why cant light dependant stage be reffered to as dark reaction

Answer 4

it needs atp and reduced nadp which are produced in the light dependant stage

Question 5

Suggest two ways in which the ultrastructure of the chloroplast can be altered by high
temperatures.

Answer 5

damage to chlorophyll / reduction
in pigment (1)
which will reduce the light
dependent stage (1)damage to membranes in
chloroplast / reduction in sites for
light capture (1)
which will reduce the light
dependent stage (1)
damage to membranes in
chloroplast / reduction in reaction
sites for electron transfer (1)
which will reduce,
photophosphorylation / ATP
production in the light dependent
stage (1)
damage to membrane around
chloroplast / release of enzymes
(1)
which will reduce, light
independent stage / Calvin cycle

Question 6

limiting factor

Answer 6

the factor that will, determine /
limit when at, low(er) / sub-optimal /
AW, level ✔

Question 7

why is dna needed in chloroplasts

Answer 7

provides gene needed for protein synthesis,for chlorophyll synthesis for production of electrons for production of atp synthase

Question 8

where is etc found

Answer 8

in thylakoid membrane

Question 9

tlc

Answer 9

ensure hands don’t touch plate so fingerprints arent transferred
make sure plate doesnt touch sides of jar because the condenstaion of jar may affect movement of spots

Question 10

how is light harvested

Answer 10

pigments are in photosystems
light energy is absorbed by pigments
electron excited to high energy level
energy is passed from one pigment to antoerh to the reaction centre
range of accessory pigments allow a range of wavelengths to be absorbed

Question 11

how is thylakoid membrane adapted

Answer 11

contains pigments
contains electron transport chain
has a large surface area for light absorption