Organic compounds: Biomolecules
Having learnt the structure of the cell, we can now understand that each component of the cell is responsible for a specific function. The cell components are made of collection of molecules called as cellular pool, which consists of both inorganic and organic compounds. Inorganic compounds include salts, mineral ions and water.
Organic compounds are carbohydrates, lipids, amino acids, proteins, nucleotides, hormones and vitamins. Some organic molecules remain in colloidal form in the aqueous intracellular fluid. Others exist in non-aqueous phases like the lipid mem-brane and cell walls. The cell maintains this pool by the intake and elimination of spe-cific molecules (Figure 8.1).
The minerals essential for plant growth are of two types: macronutrients, which are required in larger amounts (Eg. Potassium, phosphorus, calcium, magnesium, sulphur and iron) and micronutrients, which are required in trace amounts (Eg. Cobalt, zinc, boron, copper, molybdenum and manganese) and are essential for enzyme action. Example, Manganese is required for activity of enzyme needed for synthesis of oligosaccharides and glycoproteins. Molybdenum is necessary for fixation of nitrogen by enzyme nitrogenase.