What is the Difference Between Collagen and Keratin?

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Collagen and keratin are both structural proteins found in the human body, but they have distinct differences in their structure, functions, and locations.

Collagen:

  • Made up of three polypeptide chains forming a helical structure.
  • Present in connective tissues such as ligaments, tendons, and part of the dermis.
  • Also found in other structures like cornea, cartilage, bone, blood vessels, intervertebral discs, and dentine in teeth.
  • Provides support and cushioning to joints, promoting joint health and mobility.
  • Maintains the firmness and elasticity of the skin, reducing the appearance of wrinkles.
  • Produced in cells called fibroblasts.

Keratin:

  • Exists as an alpha chain or beta sheet linked to various residues.
  • Abundantly found in epithelial cells, protecting them from damage or stress.
  • Present in appendages such as feathers, hair, nails, horn, claws, and hooves of animals.
  • Reinforces nail structure, reducing brittleness, and promoting healthier, stronger nails.
  • Contributes to the elasticity and strength of hair strands, making them less prone to breakage and damage.
  • Aids in maintaining healthy, resilient skin.
  • Produced in cells called keratinocytes.

In summary, collagen is primarily found in connective tissues and provides support to joints and skin, while keratin is mainly found in epithelial cells and appendages such as hair, nails, and skin, providing strength and resilience.

Comparative Table: Collagen vs Keratin

Here is a table comparing the differences between collagen and keratin:

Feature Collagen Keratin
Definition Collagen is a fibrous protein composed of three polypeptide chains forming a helical structure. Keratin is a fibrous protein that exists as an alpha chain or beta sheet linked to various residues.
Function Collagen is a key component of connective tissues, cartilage, and bones, providing support and cushioning to joints, promoting joint health and mobility, and maintaining skin's firmness, elasticity, and youthful appearance. Keratin is found in the skin, hair, and nails, providing strength, elasticity, and resilience to these structures.
Abundance Collagen is the most abundant protein in the human body, found in the extracellular matrix and connective tissues. Keratin is a structural protein abundantly present in the skin, hair, and nails, as well as in epithelial cells and appendages such as feathers, hairs, nails, horns, claws, and hooves.
Production Collagen is produced by fibroblast cells. Keratin is produced by keratinocyte cells.
Structure Collagen has a molecular structure that resembles a helix, consisting of three polypeptide chains linked by various bonds. Keratin has a molecular structure that can be an alpha helix or beta sheet, to which several disulfide bonds are present.

In summary, collagen and keratin are both structural proteins with different functions and structures. Collagen is crucial for connective tissues, cartilage, and bones, while keratin is essential for maintaining the strength and elasticity of the skin, hair, and nails.