5.5 Photosynthesis - plant cells Flashcards Preview

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Flashcards in 5.5 Photosynthesis - plant cells Deck (22):
1

define photosynthesis:

the process in which light energy is used to build complex organic molecules e.g. glucose

2

in photosynthesis light energy is made into what? and where is it stored?

chemical energy
stored in bonds of the complex organic molecules made

3

what are autotrophs?

organisms that can photosynthesise e.g. plants, algae

4

what are heterotrophs?

organisms which obtain complex molecules through eating

5

both autotrophs and heterotrophs breakdown complex organic molecules in which process? and what is the purpose of this?

respiration
to release energy for metabolic processes

6

where in a plant cell does photosynthesis take place?

chloroplast

7

chloroplasts have a network of membranes, for what purpose?

to give a large surface area to maximise light absorption

8

the membranes within chloroplasts form flattened sacs called what?

thylakoids

9

(chloroplasts) thylakoids are stacked to form what?

grana

10

(chloroplasts) grana are joined by lamellae what is lamellae?

membranous channels

11

(chloroplasts) light is absorbed by what and where are they found?

pigments e.g. chlorophyll
found embedded in thylakoid membranes

12

(chloroplasts) what is the fluid inside the chloroplasts and what is its purpose?

stroma
site of chemical reactions resulting in formation of complex organic molecules

13

why are leaves green?

due to pigment chlorophyll - it reflects green light

14

what is the primary pigment in plants?

chlorophyll a

15

what are some other pigments in plants?

chlorophyll b
xanthophylls
carotenoids

16

why are plants sometimes different colours?

different combinations of pigments which reflect different wavelengths of light

17

what are the two stages of photosynthesis?

light dependant stage
light independent stage

18

in the light dependant reaction light is converted to what type of energy?

chemical energy

19

in the light dependant reaction, electron flow is created by what?

the effect of light on the chlorophyll causing photolysis

20

what is photolysis?

splitting of water into protons, electrons and oxygen

21

what are the products of the light dependant reaction?

reduced NADP
ATP
oxygen

22

in the light independent reaction protons are used to reduce what?

CO2
to produce sugars and other organic molecules

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