presentation about photosynthesis

2. Muhammad Hasnain Ibrahim
Sohail Ahmed
Muhammad Qasim Sardar
Laiba Mehak
Sobia Shabbir
Syeda Arooj Asad

4. Photosynthesis
• An anabolic, endergonic, carbon dioxide (CO2) requiring
process that uses light energy (photons) and water (H2O) to
produce organic macromolecules (glucose).
6CO2 + 6H2O  C6H12O6 + 6O2
glucose
SUN
photons

5. These are the things a plant needs for
photosynthesis-- the process by which a
plant makes its own food.
1. water
2. carbon dioxide
3. light energy from the Sun

6. Carbon dioxide enters the
leaf through the stomata.
Plants absorb water
through their roots.
The green leaves of a plant
Absorb light energy from the Sun.
.

7. overview of photosynthesis
OVERVIEW OF PHOTOSYNTHESIS
PLANTS TAKE IN
CO2 AND H2O
PLANTS MAKE GLUCOSE
AND OXYGEN
SUNLIGHT PROVIDES
THE ENERGY
FOR PHOTOSYNTHESIS
water
carbon
dioxide
light
carbohydrates
oxygen
SUNLIGHT CAPTURED
BY CHLOROPHYLL

9. Stomata (stoma)
• Pores in a plant’s cuticle through which water and gases are
exchanged between the plant and the atmosphere.
Guard CellGuard Cell
Carbon Dioxide
(CO2)
Oxygen
(O2)

10. Photosynthesis
•2 Phases:
•Light reactions
•Dark reactions (aka Calvin cycle)
Light Reaction Dark Reaction

11. Light-dependent
• converts light energy into
chemical energy; produces
ATP molecules to be used to
fuel light-independent
reaction
Light-independent
• uses ATP produced to make
simple sugars.

12. Light-dependent reaction (LIGHT
Reaction)
• Requires light
• Occurs in chloroplast (in thylakoids)
• Chlorophyll (thylakoid) traps energy from light
• Light excites electron (e-)
• Kicks e- out of chlorophyll to an electron transport chain
• Electron transport chain: series of proteins in thylakoid membrane

13. Light-dependent reaction (LIGHT
Reaction)
• Energy lost along electron transport chain
• Lost energy used to recharge ATP fromADP
• NADPH produced from e- transport chain
• Stores energy until transfer to stroma
• Plays important role in light-independent reaction
• Total byproducts: ATP, NADPH, O2

14. Light-dependent reaction (LIGHT
Reaction)
• How did we get O2 as a byproduct?!
• Photolysis: replaces lost electrons by splitting water

15. Light-independent reaction (Dark
Reaction)
• Does not require light
• Calvin Cycle
• Occurs in stroma of chloroplast
• Requires CO2
• Uses ATP and NADPH as fuel to run
• Makes glucose sugar from CO2 and Hydrogen

16. Light-independent reaction (Dark Reaction)
6CO2 + 12H2O + light energy C6H12O6 + 6O2 + 6H2O
• “Dark” reaction:
Calvin cycle
• regenerative
• anabolic
• CO2 in, sugar out
• during daylight
CO2
NADP+
ADP
Pi+
RuBP 3-Phosphoglycerate
Calvin
Cycle
G3PATP
NADPH
Starch
(storage)
Sucrose
(export)
Chloroplast
Light
H2O
O2

18. Photosynthesis Review
•What goes in? (the reactants)
•What comes out? (the products)
H2O Light Reaction Dark Reaction C6H12O6
chlorophyll
6CO2 + 6H2O 6O2 + C6H12O6
light
chlorophyll

19. PHOTOSYNTHESIS
• What affects photosynthesis?
• Light intensity: as light increases, rate of photosynthesis increases

20. PHOTOSYNTHESIS
• What affects photosynthesis?
• Carbon Dioxide: As CO2 increases, rate of photosynthesis increases

21. PHOTOSYNTHESIS
• What affects photosynthesis?
• Temperature:
• Temperature Low = Rate of photosynthesis low
• Temperature Increases = Rate of photosynthesis increases
• If temperature too hot, rate drops

22. Why is Photosynthesis Important toThe
Ecosystem?
•It provides food.
•It removes carbon dioxide.
•It helps in industrial activities.

23. It Provides Food…
• Plants and algae rely on photosynthesis to create
and store energy become food for many other
organisms, transferring that energy to organisms
at all levels of the food chain. When herbivores
eat plants, they absorb the energy stored by
plants through photosynthesis. When carnivores
consume herbivores, they also consume
the stored energy originally captured by plants
and later by the herbivores. Decomposers feed off
of tissue from dead carnivores, also absorbing the
energy that passed through the food chain from
the plants, herbivores and carnivores.

24. It Provides Food…
• The absence of plants, resulting from non-existence of the
process of photosynthesis, will start a chain of reactions that
will end all animal life in the ecosystem. Animals are not able
to produce the food they need for sustaining life. Animals
cannot produce from simple chemicals, complex compounds
required by them to create and sustain their life.They can only
produce complex compounds required by them from other
complex compounds produced by plants. In this way, animals
get their food either from plants, or from the animals who live
off plants.Thus without plants there will be no animals
subsisting directly on food from plants. And in absence of such
animals there will be no animals subsisting on food obtained
from other animals.Thus without photosynthesis there will be
no plant or animal life on earth.

25. It Removes Carbon
Dioxide…
• Photosynthesis converts carbon dioxide into oxygen. During
photosynthesis, carbon dioxide leaves the atmosphere and
enters the plant and leaves as oxygen. In today's world, where
carbon dioxide levels are increasing at unprecedented rates, any
process that removes excess carbon dioxide from the
atmosphere is ecologically and environmentally important in
nature. In fact, microalgae are being examined as a potential
source of carbon dioxide removal in industries that release high
amounts.

26. It Helps in Industrial Activities…
•If there is no photosynthesis in the ecosystem, there will
be no plants and loss of plant life on Earth through
activities like logging or land development pose a threat
to the primary production of the Earth.

27. THE END…
Hope you don’t find it boring or whatever…