transpiration cohesion tension theory
Function
Scientists
photosynthesis
Process by which plants and organisms transform light energy into chemical energy
light energy is captured
used to convert water, carbon dioxide, and minerals into oxygen, Glucose and ATP
epidemical tissues
guard cells
stomates
Carbon dioxide + water + sunlight ---> Oxygen + Glucose + ATP
gas exchange
diffuses into stomates
stomates open and closes
opens
opens and closes
prevents too much water vapour lost
increased water volumes
increased temperature
increased light intensity
regulates gas exchange and water vapour loss
Transpiration cohesion tension theory
transpiration creates tension
water loss due to transpiration
intermolecular attraction (cohesion)
water is polar
oxygen forms hydrogen bond
attractive force is responsible for surface tension
one particle is lost
pulls another particle due to the process of cohesion and tension
responsible for most of the water movement in a plant
tension in mesphoyll
water is pulled up due to cohesion
water travels from high to low
Transpiration cohesion tension theory
E.A. Strasburger
said that living cells are not involved in lifting water
His experiment involved immersing woody stems in a sulfuric solution
discovered that water was still transported up the leaves
Henry Dixon and John Joly
interested in Strasburgers discoveries
published an explanation on why it happens in 1895
In 1914, henry Dixon amended his thesis
Photosythenis
F. F. Blackman
Jean Senebier
Nicolas-Théodore de Saussure
vascular Tissues
Xylem
Pholem
made up of rows of cells that form a contituous tube
made up of elongated dead cells that are impermeable to water
Transports water & minerals
drawn upwards in the leaves
movement of water
transpiration stream and evaporation
Movement of water was due to physical movement
Transports sugars
made up of rows of cells that form a contituous tube
made up of living cells
they transport sucrose and amino acids up and down the the plant
Products for photosynthesis