B8 - Photosynthesis Flashcards
What is the word equation for photosynthesis?
carbon dioxide + water -> glucose + water
What is the symbol equation for photosynthesis?
6CO2 + 6H2O -> C6H12O6 + 6O2
What sort of reaction is photosynthesis?
endothermic
Why is photosynthesis an endothermic reaction?
takes light engy from surrndgs. This breaks bonds holdin CO2 & H20 & causes fmtion new bonds in C6H12O6 & O2. xtra engy used for reaction take place = transferred from envrnment by light
Why does a leaf being broad make it more efficient at photosynthesis?
large surface area increases exposure to sunlight
Why does a leaf being thing make it more efficient at photosynthesis?
short diffusion distance
Why does a leaf containing chlorophyll make it more efficient at photosynthesis?
to absorb as much light as poss
Why does a leaf having veins make it more efficient at photosynthesis?
brings plenty of water in xylem to leaves for photosynthesis, takes away glucose in phloem
Why does a leaf having air spaces make it more efficient at photosynthesis?
increases surface area for gas exchange
Why does a leaf having guard cell make it more efficient at photosynthesis?
controls opening/ closing stomata - reducing water loss
How does light intensity affect the rate of photosynthesis?
light intensity ↑ = rate of phtsynths. ↑
What are the 3 limiting factors that affect the rate of photosynthesis?
- CO2 conc.
- light intensity
- temp.
How does CO2 affect the rate of photosynthesis?
↑ CO2 = ↑ rate of phtsynths.
What happens when the slope on a limiting factor/rate of photosythesis graph stops increasing?
limiting factor has changed eg. to temp.
How is glucose used in respiration?
releases energy
What is glucose stored as in plants?
insoluble storage molecule starch
What is glucose often converted into?
fats & oils
What does glucose produce, which strengthens cell walls?
cellulose
What type of acids does glucose produce?
amino acids
What is the role of amino acids inside the plant?
protein synthesis
What is needed to make amino acids from glucose?
nitrate ions from soil
If we increase the light intensity and the rate of photosynthesis also increases, what does that tell us?
light intens. = limiting factor
Why would farmers want to increase the rate of photosynthesis?
increases yield of crops
How do ventilation vents maximise the rate of photosynthesis in greenhouses?
stops plants overheating
How does having clear glass maximise the rate of photosynthesis in greenhouses?
allows more light in -> increases temp. of greenhouse
How does having a parrafin heater maximise the rate of photosynthesis in greenhouses?
warms greenhouse & releases CO2
How does having gravel under plants maximise the rate of photosynthesis in greenhouses?
allows drainage of water out pots -> waterlogged soil = little oxyg. & unable tp respire
How does having an automatic watering system maximise the rate of photosynthesis in greenhouses?
consistent & right vol. of water @ right time
How does having electric lighting maximise the rate of photosynthesis in greenhouses?
increases hours of light in Aut & Win -> ↑ light engy.
How does having a removeable netting/whitewash maximise the rate of photosynthesis in greenhouses?
reduces intense Summer sunlight -> gives plants shade
What are advantages of having a greenhouse?
- can grow plants out season
- protects plants insects
- ensures max. plant growth
What are disadvantages of having a greenhouse?
- expensive maintaining light & temp.
- uses lots engy. & water
