T4 photosynthesis Flashcards Preview

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Flashcards in T4 photosynthesis Deck (16)
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1
Q

what is photosynthesis

A

process by which plants synthesise glucose using light energy from the sun

light energy is converted into chemical energy

2
Q

where does photosynthesis take place

A

within chloroplasts in leaf palisade cells

they contain chlorophyll, a pigment which absorbs light energy

3
Q

state the equations for photosynthesis

A

Word: carbon dioxide + water → glucose + oxygen

Symbol: 6CO2+ 6H2O → C6H12O6 + 6O2

4
Q

is photosynthesis endothermic or exothermic and why

A

endo - energy is transferred from the environment to chloroplasts by light

5
Q

how can you show that a plant gives off oxygen during photosynthesis

A

using a water plant, collect gas bubbles produced during photosynthesis

the gas will relight a glowing split as it contains oxygen

6
Q

give examples of leaf adaptations which maximise the rate of photosynthesis

A

broad leaves - maximise SA
thin leaves - short diffusion distance
chlorophyll present - trap light energy
air spaces - allow CO2 to enter, O2 leave

7
Q

what are the 4 main factors that affect the rate of photosynthesis

A

temperature

light intensity

carbon dioxide concentration

amount of chlorophyll

8
Q

how does temperature affect the rate of photosynthesis

A

increasing increases as the the kinetic energy of particles is increased

rate decreases past a certain temperature as enzymes become denatured

9
Q

how does light intensity affect the rate of photosynthesis

A

increasing increases until another factor becomes limiting

10
Q

how does carbon dioxide concentration affect the rate of photosynthesis

A

increasing increases until another factor becomes limiting as CO2 is required to make glucose

11
Q

how does the amount of chlorophyll affect the rate of photosynthesis

A

decreasing decreases the rate as chlorophyll is required to absorb light energy

12
Q

what is a limiting factor

A

environmental factor which can restrict the rate of photosynthesis

13
Q

explain how you can calculate the rate of photosynthesis by measuring oxygen production

A

set up bubble potometer apparatus (pondweed in a sealed tube of water, attached to a capillary tube and a gas syringe)

oxygen gas produced causes the bubble in the capillary tube to move

distance moved by the bubble is used to calculate the volume of oxygen produced

14
Q

how can farmers use their knowledge of limiting factors to increase their profits

A

can control temperature, light intensity and CO2 concentration to achieve the fastest possible rate of photosynthesis, leading to a greater yield

15
Q

state the law which describes the relationship between the distance of a light source from a plant and light intensity

A

inverse square law - light intensity ∝ 1 /

distance2

16
Q

state 5 uses of glucose produced during photosynthesis

A

respiration

starch for storage

cellulose for strength

amino acid and protein synthesis (combined with nitrates)

lipids for energy storage in seeds