PHOTOSYNTHESIS ppt

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pHOTOSYNTHESIS: 

pHOTOSYNTHESIS

WHAT IS PHOTOSYNTHESIS?: 

WHAT IS PHOTOSYNTHESIS?

PowerPoint Presentation: 

PLANTS USE SUNLIGHT to make sugars from water and carbon dioxide. This process is called photosynthesis. It takes place mostly in the leaves, which contain the green pigment, chlorophyll.

PowerPoint Presentation: 

The chlorophyll traps some of the energy in sunlight, using it to drive a sequence of chemical reactions that results in the production of glucose and water. Oxygen is produced as a waste product. 6 CO 2 + 6 H 2 O → C 6 H 12 O 6 + 6 O 2

The process of photosynthesis : 

The process of photosynthesis

CHLOROPHYLL: 

CHLOROPHYLL The pigment chlorophyll is found inside tiny structures called chloroplasts, which are found in most of a leaf’s cells. Each leaf contains millions of chloroplasts. Inside each one, there are stacks of membranes that hold the chlorophyll molecules.

CARBON DIOXIDE: 

CARBON DIOXIDE About 0.03 % of the air is the gas carbon dioxide. It is breathed out by animals and also released when fossil fuels are burnt. For photosynthesis to occur, carbon dioxide enters a leaf through tiny pores called stomata. These are mostly on the underside of the leaf .

WATER: 

WATER For photosynthesis to proceed, a plant needs a constant supply of water. It takes the water up from the sol through its roots. The water then travels up the xylem tissue in the stem to the leaves. During photosynthesis, water molecules within the chloroplasts are split apart. This produces hydrogen ions(groups of atoms) and oxygen molecules.

GLUCOSE: 

GLUCOSE The glucose produced by photosynthesis is a simple sugar. It contains all the energy that the plant needs to grow and reproduce. A plant also uses glucose, together with essential minerals drawn up with water, to produce all the compounds in its make-up. These include starch, which acts as an energy store, and cellulose, which builds the plant’s cell walls.

OXYGEN: 

OXYGEN This gas is a by-product of photosynthesis. It passes out of the leaves through the stomata and into the air. Plants produce all the oxygen that animals and plants need for respiration. The plants themselves use only a fraction of the oxygen they make .

LIGHT ENERGY: 

LIGHT ENERGY Sunlight is a mixture of coloured light with different wavelengths. The most important wavelength for photosynthesis that of red light. This is absorbed by the pigment chlorophyll in the plant. The other wavelengths are reflected making the plant look green.

TRANSPIRATION: 

TRANSPIRATION M uch of the water reaching the leaves is lost through the stomata and evaporates. This process is known as transpiration. A plant replaces the water by taking up more through its roots. It also controls the amount transpired by closing its stomata .

TRANSPIRATION: 

TRANSPIRATION

GASEOUS EXCHANGE IN PLANTS: 

GASEOUS EXCHANGE IN PLANTS

compensation point: 

compensation point At dusk/dawn time the rate of respiration and the rate of photosynthesis is same. This process is called as compensation point.

PowerPoint Presentation: 

In bright light , Photosynthesis is faster than respiration. Rates of respiration and photosynthesis are equal therefore no exchange of gases with air. In darkness no photosynthesis takes place.

EFFECTS OF EXTERNAL FACTORS ON RATE OF PHOTOSYNTHESIS: 

EFFECTS OF EXTERNAL FACTORS ON RATE OF PHOTOSYNTHESIS

PowerPoint Presentation: 

The factors that change the rate of reaction whether the concentration is low or high and keep the other factors constant is known as limiting factors. Since there is only 0.03% of carbon-dioxide in the air, it seems that the shortage of carbon-dioxide can be an important living factor. The main effect of extra carbon-dioxide is to slow down the rate of oxidation of sugar by a process called photorespiration and this produces the same effect as an increase in photosynthesis.

THANK YOU: 

THANK YOU