1. PHOTOSYNTHESIS
SREELAKSHMI M
NATURAL SCIENCE

2. PHOTOSYNTHESIS
 Photosynthesis (Gk.Photon- light, Synthesis- Putting
together) is a process by which green plants
synthesis carbohydrates and evolve molecular oxygen
using carbon dioxide, water, light energy and
chlorophyll.
It is a metabolic process which provides food to
biological world and also purifies atmospheric air by
removing carbon dioxide and evolving oxygen.

4. • Chloroplast is the main site of photosynthesis in plants.
• They occur chiefly in the mesophyll cells ofleaves.
• Chloroplast is a double membrane bounded organelle
consist of fluid part called stroma and disc shaped
membranous grana.
• Each grana is stalked together to form thylakoidsystem
• Thylakoid system is connected together bystroma
lamellae.
WHERE DOES PHOTOSYNTHESIS
TAKES PLACE??????

5. STRUCTURE OF CHLOROPLAST
Leaf section
Plant cell
Structure of chloroplast

6. PHOTOSYNTHETIC PIGMENTS
• Photosynthetic pigments are light sensitivepigments,
located in the thylakoidmembranes.
• Photosynthetic pigments are of two major groups,principal
pigments and accessorypigments.
• The magnesium containing greenpigment
chlorophyll-a is the principlepigment.
• The accessory pigments includes chlorophyll-b and
carotenoids.

7. CHEMISTRY OFPHOTOSYNTHESIS
• Photosynthesis is an extremely significant
biological phenomenon and a fundamental
process.
• The raw materials of photosynthesis includes
carbon dioxide andwater.
• Its end product includes sugar, water and oxygen.

8. PHASES OFPHOTOSYNTHESIS
• The whole process of photosynthesis can be divided
into two phases; light phase and dark phase.
• As the name indicateslight phase takes place only in
the presence of light and dark phase is light
independent.
• Light phase is the photochemical phase were energy
molecules such as ATP and NADPH areproduced.
• Dark phase is the light-insensitive phase were
synthesis of carbohydrates takesplace.

9. LIGHT AND DARKPHASES

10. • The overall photosynthetic process can be represented
as a chemical equation asfollows:
• 6CO2 + 12 H2O C6H12O6+ 6H2O+6O2
• Cyclic chemical reactions in the dark phasewere discovered
by scientist Melvin Calvin.Hence this phase is also called
Calvin cycle.
• The complex process involved in photosynthesis was
unfolded after long year of study and experimentation.
• Photosynthesis remains as an aspiring area of research even
today.

11. AFTER PHOTOSYNTHESIS
• After photosynthesis glucose is formed along with
water and oxygen.
• Glucose is easily soluble in water thus it cannot be
stored in the plant body. Therefore plants store
glucose in the form of insoluble starch in leaves.
• Plants utilizes starch as a source of energy for life
activities and to prepare substances required for
growth.

12. PHOTOSYNTHE
SIS
GLUCOS
E
STARCH
SUCROSE
METABOLIC
ACTIVITIES
Protein
(Legumes)
Fat
(Oil seeds)
Fructose
(Fruits)
SUCROSE
(Sugarcane)
PHOTOSYNTHESIS
GLUCOSE

13. THANKYOU…