Proteins and their functions

PROTEINS AND THEIR BIOLOGICAL SIGNIFICANCE

  • Proteins are the main structural and functional molecules of all living organisms.
  • Proteins are synthesized from amino acids, which are joined together by peptide bond to form a linear chain. Functions of proteins depend on the amino acid sequence.
  • These chains are then folded into various ways to form the 3 – dimensional structure of proteins.

Functions of proteins

  • Most of the enzymes involved in the biochemical reactions in the body are protein in nature.
  • Many hormones are proteins or peptides in nature. Eg: Insulin
  • Proteins are seen in association with DNA molecules, where it controls the gene transcription and translation.
  • Proteins are involved in the transport processes. Eg: Hemoglobin in erythrocytes involved in the transport of O2. Some transport proteins bind with steroid hormones and transport them to the other parts of the body for action. Lipoproteins transport lipids.
  • Proteins have protective role in the body. Immunoglobulins and interferons are proteins that protect humans against bacterial and viral infections.
  • Structural proteins like collagen and elastin provide structural strength and elasticity to organs and the vascular systems.
  • Some proteins are used as nutrients eg: ovalbumin of egg white and casein of milk are used as nutrients.
  • Proteins are involved in the maintenance of osmotic pressure of plasma.
  • Some proteins like actin and myosin are involved in the contraction of skeletal muscles.
Last modified: Tuesday, 22 March 2011, 12:17 PM