Photosynthesis Flashcards
What is photosynthesis
Photosynthesis is the chemical change which happens in the leaves of green plants. It is the first step towards making food- not just for plants but ultimately every animal on the planet.
What is the photosynthesis reaction described as and why
Endothermic because of the absorption of energy from the sun.
What is the equation for photosynthesis
Sunlight
Carbon dioxide + water —————> Glucose + oxygen
Chlorophyll
Symbol equation of photosynthesis
6CO(2)+6H(2)O———> C₆H₁₂O₆ +6 O ₂
Uses for photosynthesis
Respiration - glucose used to produce energy
Storage- converted to starch and oils for storage
Other useful substances- glucose can be converted into cellulose of cell walls, chlorophyll and protein for growth.
The starch test
Look over purple sheet.
What is destarching
If the result for starch is positive at the end of the experiment, it shows that the starch must have been produced during the investigation.
What factors affect photosynthesis
Light
Chlorophyll to absorb the light
Carbon dioxide
Water
A suitable temperature
Why is water not a limiting factor
If a plant is short of water the stomata will close over. This prevents entry of carbon dioxide. So it is really lack of carbon dioxide and not water.
What two ways are leaves adapted to photosynthesise
To maximise light absorption
To maximise gas exchange
What is the cuticle
The cuticle is the waxy covering which prevents water loss within the leaf
What does the xylem do
Transports water
What does the phloem do
Transports sugar (food)
What is the function of of the mesophyll cells
Palisade are packed with chloroplasts and where most photosynthesis occurs
There are two types palisade and spongy
Spongy have a large surface area for gas exchange
What are the stomata
Let’s Carbon dioxide in. Tiny holes on bottom of leaves
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