Photosynthesis: Process by which plants trap the sun’s energy and convert
it into a useable chemical form (sugar)
6CO2 + 12H2O + Solar irradiation (sunshine)C6H12O6 + 6 O2 + 6H2O
Sun’s energy:
-Packaged in particles called Photons
-Photons travel in waves
Electromagnetic spectrum: the range of wavelengths that photons exhibit
with higher energy levels having shorter wavelengths
Note: visible light only represents about 40% of the electromagnetic
spectrum.
Pigments: Molecules that absorb light. Every pigment has a characteristic
absorption spectrum: range of the spectrum that it absorbs
-the actual color that a pigment appears as is due to which wavelengths of
light that particular pigment will not absorb and therefor reflect
Chloroplast: The organelles in photosynthesizing cells of plants where
photosynthesis occurs
-contain chlorophyll: the major photosynthetic pigment in plants which is
located in the chloroplast
note: other pigments such as carotenoids and xanthophylls are also found in
the chloroplasts but in less abundance
-many chloroplasts/photosynthesizing cell
Structure:
-outer and inner membrane
-thylakoid membranes: structured in stacks called grana
-stroma: fluid component
Light Reactions (light dependent reactions): Sunlight activates
chlorophyll which in turn splits water molecules releasing oxygen and
providing electrons that fuel the electron transport system. Energy carrying
molecules are reduced NADP+ NADPH…ADP is phosphorylated ADP
+P ATP
Calvin cycle (light independent reactions)
-CO2 is concerted into sugar using the energy provided by the products of
the light reactions (NADPH & ATP)