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Guilherme Mazui

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What is the Difference Between Intrinsic and Extrinsic Proteins?

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Intrinsic and extrinsic proteins are two types of membrane proteins that interact with the cell membrane in different ways:

Intrinsic Proteins:

  • Also known as integral or internal proteins.
  • Embedded completely or partially through the lipid bilayer.
  • Extend from one side of the membrane to the other.
  • More hydrophobic.
  • Account for approximately 70% of membrane proteins.

Extrinsic Proteins:

  • Also known as peripheral or external proteins.
  • Loosely bound to the membrane from outside.
  • Located outside the membrane and bound weakly.
  • More hydrophilic and less hydrophobic.
  • Account for approximately 30% of membrane proteins.

In summary, intrinsic proteins are embedded in the lipid bilayer and extend across the membrane, while extrinsic proteins are loosely bound to the membrane from outside and are not embedded in the lipid bilayer.

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  • What is the Difference Between Intrinsic and Extrinsic Proteins?
  • Comparative Table: Intrinsic vs Extrinsic Proteins

    • Comparative Table: Intrinsic vs Extrinsic Proteins

    Here is a table comparing the differences between intrinsic and extrinsic proteins:

    Feature Intrinsic Proteins Extrinsic Proteins
    Location Embedded in the plasma membrane, either partially or completely Bound to the cell membrane from outside
    Proportion Account for approximately 70% of the membrane proteins Account for approximately 30% of the membrane proteins
    Hydrophilic and Hydrophobic Nature More hydrophobic and less hydrophilic More hydrophilic and less hydrophobic
    Attachment Firmly embedded in the lipid bilayer, having direct contact with the hydrophobic core Loosely bound to the lipid bilayer by weak non-covalent molecular attractions (ionic, hydrogen, and/or Van der Waals bonds) without much contact with the hydrophobic core
    Examples Glycophorin, rhodopsin, NADH dehydrogenase Cytochrome C, erythrocyte spectrin

    Intrinsic proteins are also known as integral proteins, while extrinsic proteins are also referred to as peripheral proteins. Intrinsic proteins are permanently attached to the plasma membrane, whereas extrinsic proteins are temporarily attached.

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    Guilherme Mazui

    Guilherme Mazui is graduated in journalism from the Federal University of Minas Gerais (UFMG) and a master's degree in Communication from the University of São Paulo (USP). In addition, he has experience in advertising writing and has worked as a content editor in several companies.