Salient Features of India constitution especially power and functions
Aadi
1.
2. Name Adil Zia
Semester 5th
R.No 618
Subject Crop Physiology
Topic photosynthesis
Department Agronomy
The University Of agriculture, Amir Muhammad Khan
Campus Mardan.
4. Agenda OF Presentation
Historical Background
Photosynthesis
Properties of Light
Light reaction
Dark Reaction
Importance of photosynthesis
Factor affecting Photosynthesis
Summary
5. History
Food comes from water and not from soil.
( Van Helmont)
Sunlight is essential for photosynthesis.
(Jan Ingenhouzz)
Plant produce glucose during photosynthesis.
( Sachs)
Light and dark reaction .
( Emerson)
C3 Cycle .
(Melvin Calvin)
6. Definition
Photosynthesis is the process whereby plants, algae, some
bacteria, use the energy of the sun to synthesize organic
compounds (sugars) from inorganic compounds (CO2
and water).
light
6 CO2 + 12 H2O ---------> C6H12O6 + 6 O2 + 6 H2O
chlorophyll
7. Properties Of Light
Light moves in waves, in energy units called
Photons.
Energy of a photon inversely proportional to
its wavelength.
Visible light contains just the right amount of
energy for biological reactions.
10. Photosynthesis occurs in chloroplasts
In most plants, photosynthesis occurs
primarily in the leaves, in the chloroplasts
A chloroplast contains:
i. stroma, a fluid
ii. grana, stacks of thylakoids
The thylakoids contain chlorophyll
Chlorophyll is the green pigment that
captures light for photosynthesis
16. Light Reaction
Light dependent reaction.
Occur in thylakoid membrane.
During light reaction , there are two
possible routes for electron flow.
a) Cyclic electron Flow
b) Non cyclic Flow
17. a. Cyclic Electron Flow
Occur in thylakoid membrane.
Use photosystem I only.
P700 reaction center chlorophyll a.
Uses electron transport chain ( ETC )
Generate ATP Only
ADP + ATPP
19. Non Cyclic Electron Flow
Occur in thylakoid membrane.
Use photosystem I and II
P680 reaction center (Ps II) chlorophyll – a
P700 reaction center (PS I) chlorophyll – a
Uses electron transport chain ( ETC )
Generates O2, ATP and NADPH
20. Non Cyclic Electron Flow
P700
Photosystem I
P680
Photosystem II
Primary
Electron
Acceptor
Primary
Electron
Acceptor
ETC
Enzyme
Reaction
H2O
1/2O2 + 2H+
ATP
NADPH
Photon
2e-
2e-
2e-
2e-
2e-
SUN
Photon
21. Non Cyclic Electron Flow
ADP + P ATP
NADP+ + H NADPH
Oxygen comes from the splitting of H2O, not CO2
H2O 1/2 O2 + 2H+
24. Dark reaction
Light independent reaction.
Calvin cycle
Also called biosynthetic pathway.
Completed in three steps.
a. Carbon Fixation
b. Reduction
c. Regeneration
26. WHY IS PHOTOSYNTHESIS SO IMPORTANT?
photosynthesis is one of the most
important biological process on earth!
• Provides the oxygen we breathe
• Consumes much of the CO2
• Food
• Energy
• Fibers and materials
27. PHOTOSYNTHESIS
What affects photosynthesis?
Light intensity: as light increases, rate of
photosynthesis increases
29. PHOTOSYNTHESIS
What affects photosynthesis?
Temperature:
Temperature Low = Rate of photosynthesis low
Temperature Increases = Rate of photosynthesis increases
If temperature too hot, rate drops
30. Summary
Photosynthesis is the process by which
autotrophic organisms use light energy
to make sugar and oxygen gas from
carbon dioxide and water.
31. The Calvin cycle makes
sugar from carbon
dioxide
– ATP generated by the light
reactions provides the energy
for sugar synthesis
The NADPH produced by the
light reactions provides the
electrons for the reduction of
carbon dioxide to glucose
Light
Chloroplast
Light
reactions
Calvin
cycle
NADP
ADP
+ P
The light reactions
convert solar
energy to chemical
energy
Produce ATP & NADPH
Summary
