Nutrition in plants, Photosynthesis (BIO)

In Glogpedia

by Qianlin
Last updated 8 years ago

Make a copy Make a copy function allows users to modify and save other users' Glogs.


Toggle fullscreen Print glog
Nutrition in plants, Photosynthesis (BIO)

Nutrition in plants

Plants are Photoautotrophs, they use light energy to make their own food.

They make food with the process of...PHOTOSYNTHESIS.

stages:Light dependent:-Chlorophyll absorbs light energy and converts it into chemical energy-Carries out Photolysis:Light energy is used to split water molecules into oxgen and hydrogen atoms.-Enzymes are required.Light-independent:-Uses energy from light dependent process.-Hydrogen atoms are used to reduce carbon dioxide.-Enzymes required.


carbon dioxide

Destarch the plants.Then,cover the pots with polythene bags to prevent release of Carbon dioxide.Jar A with addition of soda lime and concentrated sodium hydroxide.Jar B with water added as control.Expose both jars to strong sunlight, before testing with iodine test after 6 hours.Results:set up A: remains yellow.set up B: turns blue black.


Destarch the plant.Use an aluminium foil to wrap around an attached leaf.Expose the plant to strong sunlight.Remove the foil and use iodine test.Results:covered part: remains part: turns blue black.


Destarch verigated plant before exposing it to sunlight. Remove the leaf and test for starch.Results:Turns blue black: Green partsRemains yellow: non green parts

Other conditions:Water: All living things need water to survive.Suitable temperature: Determines amount of energy available.

PRODUCTS:Oxygen and GlucoseFor experiment for oxygen: Use an aquatic plant and then add sodium hydrogen carbonate. Submerge the plant and then dissolve 2g of sodium hydrogen carbonate before placing it in strong sunlight and testing it with a glowing splint. If the splint relights, oxygen is produced.For experiment for glucose: Use iodine test. But first boil the leaf and add ethanol. Remove then place in warm water before adding iodine.If it turns blue black, starch is present. If it remains yelow, no starch is present.

Limiting Factors:

Light Intensity:An increase of light causes increase of rate of photosynthesis until maximum point. As maximum amount of light can be absorbed by the chlorophyll.

Concentration of carbon dioxide:An increase of carbon dioxide causes an increase of rate of photosynthesis until maximum point. As the Stomatal openings are the largest, maximum amount of carbon dioxide is absorbed.

Temperature :Increase of temperature causes increase of reaction until optimum temperature is reached. After optimum temperature, rate of reaction decreases till 0.

What happens to the glucose?carbohydrates:Used for respiration for cellular activities and to make cellulose cell walls.Proteins:Form amino acids: Nitrate ions from soil + glucoseFats:Form fats for synthesis of protoplasm: excess glucose.

structure of the leaf:Lamina(leaf blade)- Large and flat to maximise exposure to sunlight and to reduce distance for gas to travel.Petiole(leaf stalk)-Minimal overlap for maximum expose to sunlight.Mid Rib(central vein)xylem and phloem to ensure supply of mineral salts and water, and the removal of food.

Internal leaf structure:Mesophyll tissues:- palisade(maximum absorption of light energy) and Spongy(Release of carbon dioxide gas)Epidermal tissues:- covered by cuticle, dont contain chloroplast, but contain stomata.Upper epidermial lesser stomata as it is exposed to sunlight) and Lower epidermial(more stomata as would not lead to loss of water)Network of veins:- xylem(water and mineral salts) and phloem(food; carbohydrates)

Presence of sunlight: Guard cell well expand. Opening the stomata.Without sunlight:Guard cells will shrinl and the stoma will close.



    There are no comments for this Glog.