All the living organisms are basically made up of C, N, S, P, H and O. How do they enter the living forms? Discuss.

Living organisms are composed of essential elements such as carbon (C), nitrogen (N), sulfur (S), phosphorus (P), hydrogen (H), and oxygen (O). These elements play crucial roles in the structure and function of biological molecules. Understanding how these elements enter living forms is fundamental to comprehending biological processes.

Sources of Essential Elements:

1. Carbon (C):

   • Derived from atmospheric carbon dioxide (CO2) through the process of photosynthesis in autotrophic organisms.
   • Heterotrophic organisms obtain carbon by consuming organic matter from autotrophs or other heterotrophs.

2. Nitrogen (N):

   • Primarily acquired from the soil in the form of nitrates (NO3-) or ammonium ions (NH4+).
   • Nitrogen-fixing bacteria in soil or symbiotic relationships with plants convert atmospheric nitrogen (N2) into forms usable by plants through nitrogen fixation.
   • Herbivores obtain nitrogen by consuming plants, and carnivores obtain it by consuming other animals.

3. Sulfur (S):

   • Absorbed by plants from the soil primarily in the form of sulfate ions (SO42-).
   • Sulfur is incorporated into organic molecules such as amino acids and coenzymes.

4. Phosphorus (P):

   • Taken up by plants as phosphate ions (PO43-) from the soil.
   • Essential for nucleic acid and phospholipid synthesis, among other biological processes.

5. Hydrogen (H) and Oxygen (O):

   • Hydrogen and oxygen are abundant in water (H2O), which serves as a universal solvent for biochemical reactions.
   • Also obtained from organic compounds through processes like cellular respiration, where glucose is oxidized to produce water and carbon dioxide.

Transport and Assimilation:

• Plants:

  • Absorb essential elements through roots from the soil solution.
  • Transported via vascular tissues to various plant parts.
  • Assimilated into organic molecules through biochemical pathways.

• Animals:

  • Ingest essential elements either directly from plant-based or animal-based food sources.
  • Digestive processes break down complex molecules into elemental forms.
  • Absorbed through the intestinal wall into the bloodstream for distribution to cells and tissues.

Conclusion: The acquisition of essential elements is vital for the growth, development, and survival of living organisms. Understanding the sources, transport, and assimilation of these elements provides insights into the intricate processes underlying life on Earth.