Genotype and Phenotype

Genotype and Phenotype

The genotype of an organism refers to the entire genetic constitution ; besides, the alleles present at one or more specific loci. In other words, the genotype of an organism represents its genetic make up, the information which invariably codes for all the specific characteristic features of the organism. Im-portantly, the genotype critically designates the potential properties, but certainly not the properties themselves.

The phenotype of an organism refers to the entire physical, biochemical, and physiological make up as determined both genetically and environmentally. In other words, phenotype specifically refers to carry out a particular chemical reaction. Precisely, phenotype is nothing but the manifestation of genotype.

Within the broader perspective of ‘molecular biology’ — an organism’s genotype very much represents its collection of genes i.e., its entire DNA. Likewise, in molecular terms, an organism’s phenotype designates its collection of proteins. It has been duly observed that a major segment of a cell’s inherent characteristic features normally derive from the structures and functions of its proteins.

Interestingly, in the microbial kingdom the proteins are largely available in two distinct types, such as :

(a) Enzymatic Type (i.e., catalyze specific reactive processes in vivo (largely available), and

(b) Structural Type i.e., participate actively in relatively large functional complexes viz., ribosomes, membranes.

One may even observe that such phenotypes which solely depend upon the structural macro- molecules different from proteins viz., polysaccharides (starches) or lipids, very much rely indirectly upon the available proteins.

Example : Structure of a ‘complex polysaccharide or lipid molecule’ : It usually results from the catalytic profiles of enzymes which not only synthesize, but also initiate the process, and cause noticeable degradation of such structures.