Project Report Photosynthesis-2

GOVT.SEN.SEC.SCHOOL DALLA GUIDED BY: Mr.

DAVINDERPAL SINGH Mrs. MANDEEP VERMA Miss. SATVIR KAUR

SUBMITTED BY:  MANVIR

KAUR -10th  PARAMJIT KAUR -10th  BALJIT KAUR -10th  PRABDEEP KAUR -10th  KARAMJIT KAUR -10th  RAJWANT SINGH -10th  MANPREET SINGH -10th  PARAMJIT SINGH -10th

CONTENTS  INTRODUCTION  DEFINITION  PROCESS

OF PHOTOSYNTHESIS  PHASES OF PHOTOSYNTHESIS  FACTORS AFFECTING PHOTOSYNTHESIS  IMPORTANCE OF PHOTOSYNTHESIS

INTRODUCTION All living organisms need food. Animals obtain food from plants but plants prepare it for themselves by the process of photosynthesis. Plants are, therefore, called autotrophs (auto: self, trophe: food), and the animals which have a different mode of nutrition are called heterophs (hetro: different)

CLASSIFICATION OF AUTOTROPHS Autotrophs are classified into two types: 1. Photoautotrophs: Green coloured plants and algae which systhesis food in living cells containing chlorophyll, in the presence of sunlight, are called photoautotrophs. 2. Chemoautotrophs: They produce food by using energy obtained through chemical reaction and not from sunlight.

DEFINITION Photosynthesis is the process by which living plant cells, containing chlorophyll, produce food substances (glucose and starch), from carbon dioxide and water, by using light energy. They release oxygen as a waste product in this process.

PROCESS OF PHOTOSYNTHESIS Mesophyll cells in a leaf are the principal centres of this activity. During daytime, whenthe sunlight falls on the leaf, the light energy is trapped by the chlorophyll of the upper layers specially of the mesophyll specially palisade cells. This energy is utilized in chemical processes involved in the manufacture of food, where the raw materials used are carbon dioxide and water

The overall chemical equation of this process is as follows: 6CO2 + 12H2O

light energy chlorophyll

C6H12O6 + 6H2O+ 6O2

The 6 molecules of H2O liberated at the end of the process are those that are re-formed and are not out of the original ones.

PHASES OF PHOTOSYNTHESIS 

Light Reaction: The light reaction takes place in chlorophyll. Containing thylakoids of chloroplasts. the light reaction occurs in two main steps. Step 1. Activation of Chlorophyll. The chlorophyll on exposure to light energy become activated by absorbing photons . Step 2.Splitting of water . The absorbed energy is used in splitting the water molescule into its two components and releasing electrons. H2O H+ +OH2H+ +O +2e-

 Dark

Reaction: The term “dark reaction” does not mean that it occurs when it is dark i.e., at night. It only means that the reactions are not dependent on light.In this phase ,the hydrogen of NADPH is used to combine it with CO2 by utilising ATP energy to ultimately produce glucose . This synthesis occurs in a number of steps using certain special intermediary compound . 6RuBP +6CO2 +18ATP +12NADPH +12H+ 6RuBP +C6H12O6 +18ADP +18Pi +12NADP +6H2O

FACTORS AFFECTING PHOTOSYNTHESIS  EXTERNAL

FACTORS  INTERNAL FACTORS

EXTERNAL FACTORS  Light

Intensity  Carbon dioxide concentration  Temperature  Water content

INTERNAL FACTORS  Chlorophyll  Protoplasm  Structure

of leaf

IMPORTANCE OF PHOTOSYNTHESIS  Food

for all: Photosynthesis is ultimately the source of energy and life for all living beings, whether plants, animals or humans.  Oxygen to breathe: this is the only biological process which releases oxygen into the atmosphere. The oxygen supports all life on earth.

 Thanks