Macro and Micro Elements and their functions in plants

Macro Elements in plants:

The macro elements are as follows:
1. Carbon (C): Constitutes the plant food, cell wall, cell membrane, DNA, enzymes, etc.

2. Hydrogen (H): Along with carbon present in all the structural parts of a plant, operation of photo-synthetic and oxidative phosphorylation.

3. Oxygen (O): Along with carbon & hydrogen present in the majority of plant components, terminal oxidation in ETS.

4. Phosphorus (P): It accumulates in the meristematic regions, growing fruits as an important constituent of ATP, NADP, play important role in protein synthesis, energy transfer reactions of photosynthesis, and respiration. It is an important constituent of the cell membrane in the form of phospholipids.

5. Potassium (K): Potassium helps as an activator of 40 different enzymes including those of protein metabolism like DNA polymerase. It helps in the synthesis of chlorophyll and stomatal movement. It also helps in cell permeability and hydration.

6. Nitrogen (N): It is the major component of amino acids, nitrogen bases, nucleic acids, chlorophyll, cytochrome enzymes, plant hormones, vitamins, and coenzymes.

7. Sulphur (S): It is the major constituent of amino acids like cystine, cysteine, and methionine, vitamins like biotin and thiamine, and coenzyme A. It forms disulfide linkage to stabilize protein structure. It constitutes the sulphydryl (-SH) groups that bind with poisonous substances.

8. Calcium (Ca): It is the major component of the cell wall in the form of calcium pectate. It controls the permeability of the cell membrane, converts toxic oxalic acid to non-toxic calcium oxalate, and stabilizes chromosome structure. It helps in the translocation of carbohydrates and amino acids and activates various enzymes like amylase, arginine kinase, etc.

9. Magnesium (Mg): It is the major constituent of chlorophyll. It is the activator of various enzymes helping in protein synthesis and carbohydrate metabolism, binding of the two subunits of ribosomes during protein synthesis.

Micro Elements in plants:

The microelements are as follows:
1. Boron: It helps in the absorption and translocation of carbohydrates, facilitates the formation of calcium pectate, it stimulates the formation of the pollen tubes.

2. Molybdenum: It has an important role in the fixation and assimilation of nitrogen, it helps in the activation of the nitrate reductase enzyme.

3. Chlorine: It stimulates enzymes of photosynthesis, and helps in the photolysis of water.

4. Copper: It is a constituent of enzymes like ascorbic acid oxidase, and cytochrome oxidase, it forms plastocyanin, which is an electron carrier in photosynthesis.

5. Iron: It is a structural component of ferredoxin, flavoprotein, and other iron porphyrin protein, which helps in the synthesis of chlorophyll.

6. Manganese: It is an activator of various enzymes like nitrate reductase and other respiratory enzymes, it acts as a means of protection to chloroplast against damage induced by light.

7. Zinc: It helps in the biosynthesis of tryptophan, a precursor of IAA. It helps in protein synthesis and activates various enzymes like carbonic anhydrase, alcohol dehydrogenase, and carboxypeptidase.

8. Cobalt: Activation of enzymes like peptidases, vitamin B12, increase the ability of N2 fixation in blue-green algae.

9. Silicon: It forms the cell wall in diatoms and gives mechanical strength to the leaves of Graminae.