Photosynthesis slideshow

Cellular Processes
1st Set of Photosynthesis Reactions
Jesse, Kelsey, Mitch and Leah
AUTOTROPHS – Organisms that manufacture
their own food from inorganic substances and
HETEROTROPHS – Organisms, like animals, that
cannot manufacture
their own organic
A series of reactions linked
CELLULAR RESPIRATIONSome energy that is released
from organic compounds is
released by cells in another set
of biochemical pathways.
Autotrophs convert energy to light from the sun into
chemical energy which they primarily store in carbohydrates.
Heterotrophs obtain food by eating Autotrophs or other
heterotrophs that feed on autotrophs.
Autotrophs use the biochemical pathways to manufacture
organic compounds from Carbon dioxide and water to create
a carbohydrate and molecular oxygen is released
Cellular respiration is a metabolic process by which cells
generate energy in the form of ATP from the food molecules
and release waste products carbon dioxide and water.
Both Heterotrophs and Autotrophs use Cellular Respiration
Light reactions – The initial
reaction in photosynthesis ( In
plants )
Thylakoids – Inside the inner
membranes, arranged as
flattened sacs
Grana – thylakoids
interconnected and some are
layered on top of one another
to form stacks
Stroma – solution surrounding
Light reactions is the first stage of
photosynthesis , the process by which plants
capture and store energy from sunlight.
Thylakoids are a membrane-bound
compartment inside chloroplasts and
cyanobacteria. They are the site of the lightdependent reactions of photosynthesis.
Properties of light: the light from the sun
appears white but is actually composed of a
variety of colours known as the visible
Light travels through space as waves of energy.
Waves are measured in wavelength, the
distance between crests in a wave.
Pigment – a compound that absorbs light
- When a white lights reflects off an object different colours will
be bounced off, However the various colours will react differently
if the object contains a pigment
- Pigments absorb certain colours more strongly
than others
- By absorbing certain colours, a pigment subtracts
those colours from the Visible spectrum
- Colour transmitted by the pigment no longer
appears white but rather the light wave that is being
Located in the membrane of the thylakoids are a
variety of pigments, the most important of which
are called Chlorophylls
- Chlorophyll a - specific form of chlorophyll used in
oxygenic photosynthesis. It absorbs most energy from
wavelengths of violet-blue and orange-red light
- Chlorophyll b - Chlorophyll b helps in photosynthesis
by absorbing light energy. It is more soluble than
chlorophyll a in polar solvents because of its carbonyl
- Its color is yellow, and it primarily absorbs
blue light.
- Called an accessory pigment because it assists
Chlorophyll a in capturing light energy
Other compounds found in the thylakoid
membrane, include the Yellow, Orange, and
Brown carotenoids, also function as accessory
- By absorbing the accessory pigments enable
plants to capture more of the energy in light
- During the fall many plants lose their
chloroplasts and their leaves take on the rich hues
of the carotenoids