Photosynthesis and leaves

what type of reaction is photosynthesis

endothermic as it uses energy instead of releasing it

word equation for photosynthesis

Carbon dioxide + water = glucose + oxygen

balanced symbol equation for photosynthesis

6CO2 + 6H2O → C6H12O6 + 6O2

what does photosynthesis do for plants

it is how they make food

leaf layers from top to bottom

upper epidermis, palisade mesophyll, spongy mesophyll, xylem and phloem, guard cells, stomata

upper epidermis

provides the waxy cuticle which protects the leaf, reduces water loss and is transparent to allow light through

palisade mesophyll

main photosynthetic layer with many chloroplasts. Chloroplasts have chlorophyll which absorbs sunlight energy

spongy mesophyll

has air spaces to allow CO2 to diffuse through

leaf veins

xylem transports water, phloem transports photosynthesis products (sugars)

guard cells

open and close stomata to regulate gas exchange

stomata

air spaces to take in CO2 and release O2

what is needed for photosynthesis

carbon dioxide, water, light, energy, chlorophyll (absorbs light)

5 main glucose uses in plants

Cell walls (cellulose)

Stored as starch

Respiration (energy release)

Fats and oils (storage and cell membranes)

Nitrates → amino acids (protein for growth and repair)

how do you test how much photosynthesis has occurred in different conditions and why

by testing for starch (glucose storage) via iodine because starch is stored in the chloroplasts, and glucose is used up quickly so cannot be used to test

what does more starch visible via iodine show in a photosynthesis test

more photosynthesis occurred as more food was made