Photosynthesis

- cut down on water loss through transpiration ||  || - Main rib (leaf stalk and veins) expose leaf to maximum amount of sunlight for absorption - Large surface area- maximise sunlight absorption ||  || Plant converts products of photosynthesis, glucose into starch and store it -> insoluble (large molecule and will not diffuse out of cells), immobile, inert (does not react with other things in the cell) as compared to glucose
 * Features || Function ||  ||
 * Palisade mesophyll cells, which have chloroplasts, are arranged in right angles to upper epidermis and || Allows more cells to be exposed to sunlight and facilitate photosynthesis ||  ||
 * Spongy mesophyll, irregular cells, with large inter-cellular air space || Allow more space for gas exchange ||  ||
 * Lower surface has more stromas than the upper surface of leaves || - Stoma whose sizes are regulated are found at the lower surface to allow for gas exchange while reducing water loss through transpiration
 * Spongy mesophyll are located at the lower epidermis as they are close to the stroma ||  ||   ||
 * Leaf is thin and flat and thus have large surface area to volume ratio || -Thin to allow gas in the lower epidermis to have access to the other parts of the leaf.
 * Transparent epidermal layer and layer of cuticle || - Focus the light to let the palisade mesophyll cells absorb the sunlight ||  ||

Destarching-> placing plants in the dark to prevent photosynthesis from taking place

__Factors affecting photosynthesis__ - Light intensity - Carbon dioxide - Limit to the maximum rate of photosynthesis (saturation point) Rate of photosynthesis cannot further increase due to presence of limiting factor Increase rate of photosynthesis, increase limiting factor At every increase of 10 degress celcius, there will be an increase of two times of the rate of photosynthesis. Water molecules bind with enzymes in chlorophyll in order to split to release oxygen -On a hot day,this process will happen in a faster rate as the molecules move faster When it gets too hot, too much heat causes enzymes to denature (losing its shape), water moelcules are unable to bind with enzyme and thus plants are unable to photosynthesize

Removing chlorophyll (decolourise)-> allow for colour change in iodince test Put leaf in boiling water-> stop any reactions Submerge leaf in ethanol-> destroy phospholipid bilayer of plasma membrane which causes the leaf to be decolorised

Creepers which are under the canopy does not necessarily grow towards sunlight as they have to look for a trunk to grow on -When younger, leaf is smaller-> leaf increases in surface area when height is higher to capture as much sunlight as possible Young of ferns are very hairy -> trap moisture as they are highly vulnerable to changes in temperature thinner cells, thinner wax layers, thinner xylem (sun-screened so that they won't be too hot) Plants move in direction of sunlight Grows in mosaic way (exposed sunlight) -> canopy does not overlap each other Begonia- Top of leaf- dark green with large amounts of chloroplasts and sharp spines on surface to increase surface area Whitish coloured parts of leaf focuses light on chlorophyll (to maximise sunlight) - compound - simple - Palmate - Lobed plant makes use of hydraulic actions to make sure leaves unfold itselves
 * Adaptations of plants**
 * Shape of leafs**