Photosyntheisis - Equation of the Overall Process

• Photosynthesis means synthesis of food with the help of sunlight.
• The overall equation of photosynthesis is
  
• Photosynthesis process takes place only in green parts of the plant, mostly in leaves and to lesser extent in green stems or floral parts of the plants.
• Leaves of the plant are known as light powered food factories.
• A green substance called chlorophyll in the leaves catches the energy from sunlight, water from soil, CO₂ from air and completes the chemical form. This process is called photosynthesis.
• Chlorophyll pigments are mainly present in cell organelles called plastids (chloroplast).
• There are different kinds of chlorophyll molecules present in photosynthesis organisms. In plants mostly there are two kinds viz. chlorophyll a and chlorophyll b. Both chlorophyll a and chlorophyll b are very similar in molecular structure, except that the CH₃ group in chlorophyll a is replaced by CHO group in chlorophyll b.
• The CO₂ for photosynthesis comes from air. It seeps into leaf through tiny holes into lower surfaces known as stomata.
• Stomata are open during day time and closes during night time.
• In addition to sugar, photosynthesis also produces oxygen which sleeps out in the air.
• Photosynthesis occurs only in visible light region of wavelength 4000-7500°A. The temperature range is from -35°C to +75°C.
• Photosynthesis is the only carbon fixing process on earth. The rate of photosynthesis is optimum between 10°C to 35°C.
• Certain bacteria and algae can also capture light energy and use it to make food e.g. photosynthesis bacteria contains chlorophyll in tiny bodies called chromatophores.
• Essential elements in plants are Carbon - 45%, Oxygen - 3%, Hydrogen - 6%, Nitrogen - 13%.