Photosynthesis is the process by which plants, algae, and some bacteria use sunlight, water and carbon dioxide to produce oxygen and energy in the form of glucose. It occurs in two stages - the light-dependent reactions where light energy is captured to make ATP and NADPH using chlorophyll, and the light-independent reactions where carbon dioxide is fixed using ATP and NADPH to produce glucose. Key factors that influence photosynthesis are light, chlorophyll, temperature, carbon dioxide and water. Photosynthesis takes place in the chloroplasts of plant cells and is essential for converting sunlight into chemical energy that fuels life on Earth.

1. PHOTOSYNTHESIS
Fourth Group XII IPA 3
Compiled by :
Nyimas Zihni Badzlina

2. Photosynthesis
In Biology dictionary, Photosynthesis
can be difinite as a process of making
food that happen in the leaf, which
done by the chlorophyll and helped by
the sun light. There are some factors
which influence the photosynthesis
process, such as : light, chlorophyll,
temperature, carbondioxide, and
water.Photosynthesis is also defined as
the production of organic compounds
from inorganic molecules using light
energy trapped by chlorophyll.Green
plants use energy from light to combine
carbon dioxide and water to make
sugar and other chemical compounds.
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3. 3

4. PHOTOSYNTHESIS
chlorophyll
Carbon Dioxide + Water + Light >> Glucose +
Oxygen
chlorophyll
6CO2 + 6H2O + Light >> C6H12O6 + 6O2
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5. Location of Chlorophyll in
Photosynthetic Plant Cells
Chlorophyll is present in the internal green membranes of
the chloroplast.
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6. THE MAIN EVENTS OF PHOTOSYNTHESIS
(lower level)
The light is absorbed by the leaf’s chloroplasts. The light energy is used to
split water molecules. The break up of water releases oxygen, electrons and
protons (H+, H ions) : The electrons go to the chlorophyll, The protons are
stored in the chloroplast The oxygen passes from the chloroplast. Some will be
used by the mitochondria for aerobic respiration and the remainder will be
passed into the atmosphere. Some of the light energy is carried to the
chlorophyll to form high energy electrons. The high energy electrons and the
stored protons combine with carbon dioxide to form glucose. (C6H12O6)
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7. THE MAIN EVENTS OF
PHOTOSYNTHESIS (higher level)
Photosynthesis
takes place in
two stages; the
light stage and
the dark stage.
The light stage
needs light so it
is called the
light-dependent
stage. The dark
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8. Light Reaction
• The light stage takes place in the
chloroplast’s thylakoid membranes.
Light Absorption: All the colours of
white light (except green light) are
absorbed
by
pigments
in
the
chloroplast. Energy Transfer: The
energy is transferred to electrons.
These electrons become high energy
electrons. Within the chloroplasts are
electron acceptors. After the electron
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9. A Pathway 1 (Cyclic Electron Transport)
•
A Pathway 1 (Cyclic E
lectron
T
ransport): T
he high energy
electrons travel through a
series of electron acceptors
(electron carrier system) and
then back to the chlorophyll
molecule. As they travel
through the acceptors they lose
energy. T
his energy is in ADP
molecules. T
his is used to
combine
with
1
more
phosphate molecule to form
AT and water. T
P
his is a high
energy molecule. T addition
he
of a phosphate molecule to
ADP is called phosphorylation.
Since light is needed this
addition of phosphate is called
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10. B. Pathway 2 (Non-cyclic Electron Transport)
P
athway 2 (Non-cyclic E
lectron T
ransport): As in Stage 1 the
electron has gained energy from sunlight. T
he electron
moves from acceptor to acceptor but does not return to the
chlorophyll. As an electron moves from acceptor to acceptor
it is passed to NADP+. This causes the NADP+ to become neutral.
This NADP molecule receives another electron and becomes
NADP- (negative). The negative NADP- attracts the proton + which
was previously released when water was broken up. T molecule
he
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now becomes NADP .
H

11. Light Reactions
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12. DARK REACTIONS
DARK STAGE
The dark stage takes place in
the stroma of the chloroplast.
Unlike the light stage, the
dark stage is controlled by
enzymes and therefore
affected by temperature. The
enzyme is ribulose
bisphosphate carboxylase
oxygenase (RUBISCO). In this
cycle ATP and NADPH,
produced in the light stage,
provide the energy and
electrons to change carbon
dioxide (CO2) to
carbohydrates (C H O)
molecules. Although this 12
stage is called the dark stage

13. Conclusion
• So, photosynthesis is
an important process
that produce oxigen as
an air which used by
living things to breath,
and glucose as a
energy source in plant.
Photosynthesis
provides the chemical
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14. THANK’s FOR
YOUR
ATTENTION
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