विस्तृत व्याख्या:

Size of Human Proteome vs. Genome (मानव प्रोटिओम की विविधता):

• The human genome contains approximately 20,000 to 25,000 protein-coding genes, which is surprisingly comparable to much simpler organisms like C. elegans or Arabidopsis.
• However, the human proteome consists of several hundred thousand distinct proteins.
• The principal biological mechanisms responsible for this vast proteomic diversity are:

• Alternative Splicing (वैकल्पिक स्प्लिसिंग): A single pre-mRNA transcript can be spliced in multiple different ways by combining different exons, producing diverse mRNA transcripts and distinct polypeptide isoforms from a single gene.
• Post-Translational Modifications (PTMs): Phosphorylation, glycosylation, ubiquitination, and proteolytic cleavage further diversify functional proteins.
  • Therefore, an individual gene can encode many distinct polypeptides.