7.2 Photosynthesis Flashcards
Need ______ and ______ to make food. Oxygen is a _________ in this process.
Raw materials, energy source, by-product
Raw materials
Carbon dioxide fr air, water fr soil
Energy source
Energy needed comes fr light
Light energy absorbed by chlorophyll, converts into chemical energy in food produced
Food (use, process)
Glucose is food produced, growth and respiration
Unused glucose converts into stretch fr storage
Starch can be converted back into glucose
By-product
Oxygen, given out into air
Word equation and chemical equation of photosynthesis
Light absorbed by chlorophyll
L>
Carbon dioxide + water —-> glucose + oxygen
6CO2 + 6H2O —-> C6 H12 O6 + 6O2
How to know if photosynthesis took place
Produce starch and oxygen
Test for starch, how it works
Iodine solution, brown to blue-black in presence of starch
Iodine test for starch steps
- Boiling water: destroy cell membrane
- Hot alcohol: remove chlorophyll
- Hot water: remove alcohol, soft
- Iodine solution: test for starch
Another test to proof photosynthesis
Glowing splint relights, gas given out is oxygen
What happens when destarch
why destarch
Stored starch converts back to glucose which is then used by plant
Doesn’t contain starch b4, any starch detected later formed during experiment,
indicates photosynthesis took place
Chlorophyll necessary test
Iodine solution to green and non-green parts of variegated leaf
Green- blue-black
Non-green- brown
Starch produced in green parts
Carbon dioxide necessary test
Leaf, soda lime on watch glass (absorbs co2)
Leaf, watch glass
Both in plastic bags, under sunlight
Iodine test
Light necessary test
Black paper strip
Why no test for water
Plant dies if all water is removed
