3.2 photosynthesis

Question 1

autotropic nutrition

Answer 1

build up of simple molecules into complex oganic molecules

Question 2

heterotropic nutrition

Answer 2

the breakdown of complex organic molecules into simple molecules

Question 3

photoautotrophs

Answer 3

use lights as a source of energy

Question 4

chemoautotrophs

Answer 4

use energy from chemical reactions

Question 5

word equation for photosnthesis

Answer 5

!!
chlorophyll
carbon dioxide + water ———–> oxygen + glucose
sunlight

Question 6

leafs adaptations for photosnthesis

Answer 6

large surface area- greater exposure to sunlight
thin leaves- allow light to penetrate easier , shorter pathway for diffusion
stoma present- carbon dioxide diffuses IN here , oxygen diffuses OUT here
air spaces in spongy mesophyll layer- a shorter diffusion pathway for carbon dioxide to diffuse into photosynthesising cells
spaces between palisade cells- allows carbon dioxide to diffuse IN
transparent cuticle and upper epidermis- allos a greater absorbance onf sunlight
palisade cells are cylindrical , elongated and at right angles to leafs surface- shorter pathway for sunlight to penetrate, meaning less resistance for greater absorbance , also increases the number of palisade cells that can fit in
palisade cells contain chloroplasts- site of photosynthesis , greater absorbance of sunlight as they are at the top of the leaf , greater exposure to sunlight

Question 7

chloroplasts as transducers?

Answer 7

cinvert the energy from photons into chemical energy which was made available by ATP

Question 8

what are the 4 photosynthetic pigments you need to know

Answer 8

chlorophyll a , chlorophyll b , β-carotene , xanthophyll

Question 9

benefit of having several different photosynthetic pigments?

Answer 9

in order to maximise the amount of photons absorbed which can be converted into chemical energy for photosynthesis

Question 10

why do plan

Question 11

why do plants appear green?

Answer 11

chlorophyll molecules
absorb photons from
the blue + red areas
of the EM spectrum.
they reflect green light
which is why plants
aрpear GREEN.

the existance of carotenes
which absorb photons in
a different section can
contribute to yellow, orange and red plants

Question 12

what range of wavelengths do chlorophylld reflect

Answer 12

520 - 620 nm

Question 13

absorption peak and P? of PS1 and location

Answer 13

abs peak of 700nm
P700
intergranal lamellae