Plant nutrition
photosnythesis
the process by which plants manufacture carbohydrates from raw materials using enegry from light
carbon dioxie + water → glucose + oxygen
6CO2 + 6H2O → C6H12O6 + 6O2
light energy transformed into chemical energy
happens inside chloroplasts which is where enzymes and chlorophyll catalyse and supply energy for the reaction
leaf adaptation
to expose as much of the leaf as possible to the sunlight and air, allow sunlight to penetrate to all cells, allow CO2 and O2 to diffuse in and out as quickly as possible
leaf structure
upper epidermis
palisade mesophyll
spongy mesophyll
lower epidermis
phloem tubes
xylem tubes
glucose for energy
it is broken down by respiration to release energy
glucose used for storage
can be stored as starch. Glucose is soluble in water and reactive. Starch however isn't soluble or reactive
glucose to make other substances
it's used to make carbohydrates sucrose and cellulose and fats and oils
nitrogen
needed to make amino acids, deficiency causes weak growth and yellow leaves
magnesium
needed to make chlorophyll, deficiency causes yellowing between veins
glucose in transport
it is converted to sucrose and then changed back, because it is less reactive
before testing leaves for starch
you need to break the cell membrane with boiling water and remove its chlorophyll by dissolving it out with alchohol
before testing for photosynthesis
you need to destarch the plant, leaving it 24 hours in a dark cupboard