PHOTOSYNTHESIS IN PLANTS SITE,IMPORTANCE AND STAGES OF PHOTOSYNTHESIS

1. CHAUDHARY CHARAN SINGH UNIVERSITY
MEERUT 250004
TOPIC-Photosynthesis and its importance in
bioproductivity.
Submitted to
Dr.Vinay Panwar
Deptt. of Genetics and Plant Breeding
C.C.S. University Meerut
Submitted by:
Sanjeet verma
M. Sc Ag. 2nd sem.

3.  OVERVIEW
 Why are plant Green?
 Definition of photosynthesis.
 Importance of photosynthesis.
 Site of photosynthesis.
 Light-dependent reaction.
 Light-independent reaction/Dark reaction.
 Factors affecting Photosynthesis.
 conclusion

4.  WHY ARE PLANTS GREEN?
 Chlorophyll gives plants their green color because it does not absorb the green
wavelengths of white light.
 That particular light wavelength is reflected from the plant, so it appears green.
 Chlorophyll is located in the thylakoid membranes.

5. DEFINITION OF PHOTOSYNTHESIS
 Photosynthesis is the process by which autotrophic organisms use light energy to make sugar and oxygen gas
from carbondioxide and water.
 Occurs in plants, algae and some prokaryotes.
 Stored as carbohydrate in their bodies.

6. IMPORTANCE OF PHOTOSYNTHESIS
 Harnesses the sun's energy into utilizable forms of energy on earth.
 A process that most biological organisms are unable to perform.
 ATP is used to power these processes.
 Converts light energy into chemical energy in the form of glucose.
 Then the process of cellular respiration converts energy in glucose to energy in the form of ATP which is used
to power the biological process.

7. SITE OF PHOTOSYNTHESIS
 For photosynthesis the chloroplasts are the real sites.
 It is a double membrane bound organelle consisting of xanthophyll, chlorophyll, carotenoid, cytochrome,
DNA (Deoxyribose Nucleic Acid), RNA (Ribonucleic Acid), manganese, etc.
 Chloroplasts are usually significantly larger as compared with the mitochondria.
 All green parts of a plant are included in photosynthesis.
 Leaves are the very much significant organs of photosynthesis. In xerophytes such as Opuntia, the stem
is green and it carries out photosynthesis.

8.  The space that is covered by the envelope is filled with matrix termed as stroma.
 In the stroma, several grana are embedded. In every granum, various disc shaped
lamellae are available.
 These disc shaped structures are termed as thylakoids.
 They look like a stack of coins.
 This structure is termed as granum.
 Usually a chloroplast consists of 40 to 60 grana.
 The photosynthetic pigments are existed in grana.
 The stroma consists of circular DNA, RNA and enzymes for starch synthesis.

10.  L
Takes place in thylakoids (contain chlorophyll)•
 Requires light•
 Converts light energy into chemical energy•
 Light independent reaction depends on the end products (reduced NADP
and ATP) of light dependent reaction
 LIGHT DEPENDENT REACTION

11.  CYCLIC PHOTOPHOSPHORYLATION
 Cyclic photophosphorylation can be defined as the synthesis of ATP coupled to
electron transport activated by Photosystem I solely, and can therefore proceed
in long-wave-length light (03BB 2265 700 nm).
 This process is unaffected by the specific inhibitors of Photosystem II, such as
CMU, DCMU and orthophenanthroline.

12.  Non cyclic photophosphorylation
 Non-cyclic photophosphorylation refers to the process in which the electrons that are expelled from the
exciting photo center do not return.
 This process happens when both photosystems I and II are involved.
 The photolysis of water leads to the release of electrons and hence, a constant water supply is needed.

13. Light independent reaction
 Also known as calvin cycle•
 Takes place in the stroma of the chloroplast.
 No light required but need the end products (reduced NADP and ATP) of
light dependent reaction reduced NADP and ATP to produce simple sugars.
 Need an enzyme RUBISCO (Ribulose Biphosphate Carboxylase)
and carbon dioxide.

15.  Factors affecting photosyntesis
The main factors are:
1. Light intensity
2. Wavelength
3. Carbon dioxide concentration
4. Temperature
5. Water supply
6. Chlorophyll Concentration
7. Pollution

16. conclusion
All plants and animals are dependent on the sun for
energy.
This energy is made available to them by the
process of photosynthesis.
Man, like other animals, is dependent on the plants
for his food.
No Photosynthesis = No Life

17.  Refrences
1. Wikipedia.
2. http://www.tutorvista.com/content/biology/biology-
ii/nutrition/factors- affecting-photosynthesis.
3. http://en.wikipedia.org/wiki/Artificial photosynthesis.
4. Plant physiology by S.N.Pandey and B.K. Sinha.