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1. ENERGY
MATTER

2. Lesson 1:
Light
and Pigment

3. • Light is the part of the
electromagnetic spectrum that
consists of energy in the form of waves
of different lengths and energies.
• Visible (white) light is separated into
different colours (wavelengths) of light
when it passes through a prism.

4. Photosynthetic
Pigment
• A pigment is any substance that
absorb light.

5. Photosynthetic pigment molecules
are special molecules because they
are capable of converting the
incident light energy into chemical
energy.

6. If a pigment absorbs light energy, one of
the three things will occur:
1. Energy is dissipated as heat.
2. The energy may be emitted
immediately as a longer
wavelength, a phenomenon
known as fluorescence.
3. Energy may trigger a chemical
reaction as in photosynthesis.

7. Chlorophyll
• the green pigment
common to all
photosynthetic cells
• absorbs all
wavelength of visible
light and only amount
of green, which it
reflects and is
detected by our eyes.

8. • All photosynthetic
organisms (plants,
certain protists,
bacteria, and
cyanobacteria) have a
chlorophyll.
• Accessory pigments
absorb energy that
chlorophyll does not
absorb.

9. • These pigments include
chlorophyll b (also c,d, and e in
algae and protists), xanthophylls,
and carotenoids (such as beta-
carotene).
• Carotenoids and chlorophyll b
absorb some of the energy in the
green wavelength.

10. Chlorophyll
• Chlorophyll is also
the site of
considerable
nitrogen and sulfate
reduction, amino
acid assimilation,
protein synthesis
and fatty acid
production.

11. Chlorophyll
• These anabolic
(building-up)
reactions, which
depend directly on
the light reactions of
the photosynthesis for
ATP and NADH and
the Calvin cycle for
skeleton, supply the
essential amino acids,
proteins and lipids.

12. Carotenoids
• responsible for absorbing
light of different
wavelengths and
together with other
pigments absorb much of
the available light.
• serve as sunscreens to
protect the chloroplasts
from damage
(photodamage) by
intense light

13. • Cyanobacteria (known
as blue-green algae)
and red algae have
additional pigments
called phycobilins that
are red or blue and
absorb the colours of
the visible light that
are not effectively
absorbed by
chlorophyll and
carotenoids.
Red Algae

14. • Purple and green bacteria contain
bacteriochlorophyll that absorb
infrared light.
• These bacteria perform
photosynthesis under anaerobic
conditions and uses infrared light
for photosynthesis.

15. Lesson 2:
The Structure of
the Chloroplast
and
Photosynthetic
Membranes

16. Chloroplasts
• The entire
photosynthetic
pathway occurs in
large organelles known
as chloroplasts which
are much larger than
mitochondria.
• consist of cristae-like,
membranous grana
embedded in a matrix-
like stroma

17. Chloroplasts
• The grana are stacks
of flattened,
membranous
vesicles, or
thylakoids.
• Thylakoid is the
structural unit of
photosynthesis.

18. Chloroplasts
• Photosynthetic
pigment carriers are
embedded in the
membranes of the
thylakoids.
• In eukaryotes (plants
and algae), these
thylakoids are located
in chloroplasts.

19. • Photosystems are functional units
composed of an antenna and electron
carriers.
• There are two types of photosystems; I
and II, named in order of their discovery.

20. • These photosystems produce ATP and
NADPH which will be sources of energy
of the Calvin-Benson cycle.
• The pigments in a photosystem do
nothing more than “harvest” light
energy.