T4 photosynthesis Flashcards
what is photosynthesis
process by which plants synthesise glucose using light energy from the sun
light energy is converted into chemical energy
where does photosynthesis take place
within chloroplasts in leaf palisade cells
they contain chlorophyll, a pigment which absorbs light energy
state the equations for photosynthesis
Word: carbon dioxide + water → glucose + oxygen
Symbol: 6CO2+ 6H2O → C6H12O6 + 6O2
is photosynthesis endothermic or exothermic and why
endo - energy is transferred from the environment to chloroplasts by light
how can you show that a plant gives off oxygen during photosynthesis
using a water plant, collect gas bubbles produced during photosynthesis
the gas will relight a glowing split as it contains oxygen
give examples of leaf adaptations which maximise the rate of photosynthesis
broad leaves - maximise SA
thin leaves - short diffusion distance
chlorophyll present - trap light energy
air spaces - allow CO2 to enter, O2 leave
what are the 4 main factors that affect the rate of photosynthesis
temperature
light intensity
carbon dioxide concentration
amount of chlorophyll
how does temperature affect the rate of photosynthesis
increasing increases as the the kinetic energy of particles is increased
rate decreases past a certain temperature as enzymes become denatured
how does light intensity affect the rate of photosynthesis
increasing increases until another factor becomes limiting
how does carbon dioxide concentration affect the rate of photosynthesis
increasing increases until another factor becomes limiting as CO2 is required to make glucose
how does the amount of chlorophyll affect the rate of photosynthesis
decreasing decreases the rate as chlorophyll is required to absorb light energy
what is a limiting factor
environmental factor which can restrict the rate of photosynthesis
explain how you can calculate the rate of photosynthesis by measuring oxygen production
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
how can farmers use their knowledge of limiting factors to increase their profits
can control temperature, light intensity and CO2 concentration to achieve the fastest possible rate of photosynthesis, leading to a greater yield
state the law which describes the relationship between the distance of a light source from a plant and light intensity
inverse square law - light intensity ∝ 1 /
distance2
