Photosynthesis
Definition of Photosynthesis
-> Is a natural biological process in which photosynthetic
organisms use light energy to convert carbon dioxide and water
into glucose and oxygen.
-> It is essential for life on Earth because it not only produces
oxygen and food but also helps remove carbon dioxide from the
atmosphere. Without photosynthesis, most life on Earth could
not exist.
Organisms That Perform Photosynthesis
-> Plants
-> Algae
-> Cyanobacteria
Site of Photosynthesis
Photosynthesis takes place mainly in chloroplasts. In plants and
algae, it occurs inside chloroplasts, while in cyanobacteria it
takes place on photosynthetic membranes because they do not
possess chloroplasts.
, Photosynthetic Pigments
-> Chlorophyll a – a blue-green pigment found in all
photosynthetic organisms
-> Chlorophyll b – a yellow-green pigment that absorbs mainly
blue and red light.
-> Carotenoids – natural yellow, orange, and red plant pigments
that act as powerful antioxidants and serve as precursors of
vitamin A.
*Difference between chlorophyll a and chlorophyll b: The
third ring of chlorophyll a contains a methyl group, whereas
chlorophyll b contains an aldehyde group in the same position.
Reactants and Products of Photosynthesis
-> Reactants: Water (H₂O), carbon dioxide (CO₂), and light
energy.
-> Products: Glucose (C₆H₁₂O₆) and oxygen (O₂).
Photosynthesis Equation
-> Word equation: Carbon dioxide + water (in the presence of
light and chlorophyll) → glucose + oxygen
-> Chemical equation: 6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂
Definition of Photosynthesis
-> Is a natural biological process in which photosynthetic
organisms use light energy to convert carbon dioxide and water
into glucose and oxygen.
-> It is essential for life on Earth because it not only produces
oxygen and food but also helps remove carbon dioxide from the
atmosphere. Without photosynthesis, most life on Earth could
not exist.
Organisms That Perform Photosynthesis
-> Plants
-> Algae
-> Cyanobacteria
Site of Photosynthesis
Photosynthesis takes place mainly in chloroplasts. In plants and
algae, it occurs inside chloroplasts, while in cyanobacteria it
takes place on photosynthetic membranes because they do not
possess chloroplasts.
, Photosynthetic Pigments
-> Chlorophyll a – a blue-green pigment found in all
photosynthetic organisms
-> Chlorophyll b – a yellow-green pigment that absorbs mainly
blue and red light.
-> Carotenoids – natural yellow, orange, and red plant pigments
that act as powerful antioxidants and serve as precursors of
vitamin A.
*Difference between chlorophyll a and chlorophyll b: The
third ring of chlorophyll a contains a methyl group, whereas
chlorophyll b contains an aldehyde group in the same position.
Reactants and Products of Photosynthesis
-> Reactants: Water (H₂O), carbon dioxide (CO₂), and light
energy.
-> Products: Glucose (C₆H₁₂O₆) and oxygen (O₂).
Photosynthesis Equation
-> Word equation: Carbon dioxide + water (in the presence of
light and chlorophyll) → glucose + oxygen
-> Chemical equation: 6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂
