Transpiration and leaves

A plants with leaves ( Not cactus )

Transparent layer to let sunlight in for photosynthesis in on the top of the leaf.

Waxy layer on top of leaf, minimises water loss

Layer of long cylindrical cell where photosynthesis takes place. chlorophyll

Layer of cells with air spaces between them were gas exchange takes place

Transports water

Transport dissolved sugar

Transparent layer with pores (stomata)T

The loss of water through stomata via diffusion

Swell unevenly due to thicker inner walls and thinner outer walls. To open the guard cell becomes turgid by water entering it and its structure allows it to bend outward, revealing the opening of stoma.

Photosynthesis Metabolite in chemical reactions Transport minerals - phosphates and nitrates Maintain turgidly of cells Maintain temperature

They are absorbed by active transport and are dissolved in the water

DNA, amino acids and chlorophyll

DNA and ATP

Transport water and minerals up the plant and provides support

Lignin

Light ( Increases open stomata so water can diffuse out) Temperature ( Increases kinetic energy and evaporation ) Increasing wind ( Decrease water vapor outside of leaf and increase water potential gradient Decrease humidity

1) Water diffuses out the leaf through the stomata (Transpiration) 2) Water lost from the air spaces is replaced by water from the cell walls of the mesophyll cells 3) This lowers the water potential of the mesophyll cells. Water is drawn from the xylem into the mesophyll cells by osmosis down a water potential gradient 4) Water moves up the xylem vessels in a continuous column to replace this lost water this upward movement is called the transpiration stream 5) The upward pulling force acting on the xylem can be so great that water is under tension exerting an inward pull on the walls of the xylem vessels known as cohesion tension theory 6) Water molecules also stick to cellulose in xylem walls (adhesion) 7) This pulls up a continuous column of water in the xylem to the mesophyll tissues leave along a water potential gradient (Transpiration pull) and generates negative pressure inside the xylem

= Lower pressure inside than outside

Xylem contains hollow walls to allow for continuous columns of water Xylem contains lignin which waterproofs from water Xylem contains cellulose for the water to bind to (adhesion)