Author
Home > Science > What is the Difference Between Gap Junction and Tight Junction?

Guilherme Mazui

•4 minutes to read

What is the Difference Between Gap Junction and Tight Junction?

🆚 Go to Comparative Table 🆚

The main difference between gap junctions and tight junctions lies in their function and the molecules they allow to pass between cells. Here are the key differences:

Gap Junctions:

  1. Act like tunnels for water and ions, especially in cells that propagate electrical signals.
  2. Composed of clusters of connexons that allow molecules to pass between cells.
  3. Particularly important in cardiac muscle, where the electrical signal to contract spreads rapidly between heart muscle cells as ions pass through, allowing the cells to contract in tandem.
  4. Serve a coordinating role in various groups of cells, such as those containing electrically excitable cells.

Tight Junctions:

  1. Create a watertight seal between two adjacent animal cells, blocking water, ions, and other molecules.
  2. Composed of many individual groups of tight junction proteins that hold cells tightly against each other.
  3. Prevent the leakage of liquid between cells, allowing a layer of cells to act as an effective barrier.
  4. Found in cells lining organs, where they help maintain the integrity and function of the organ.

In summary, gap junctions facilitate the movement of water, ions, and small molecules between cells, while tight junctions create a watertight barrier to block the passage of these substances between cells.

On this page
  • What is the Difference Between Gap Junction and Tight Junction?
  • Comparative Table: Gap Junction vs Tight Junction

    • Comparative Table: Gap Junction vs Tight Junction

    Here is a table comparing the differences between gap junctions and tight junctions:

    Feature Gap Junctions Tight Junctions
    Definition Channels connecting the cytoplasm of two adjacent cells, allowing the movement of ions, minerals, and other small molecules. A specialized connection between two adjacent animal cell membranes, creating a watertight seal and regulating the movement of water and solutes.
    Structure Composed of connexins, which form an elongated, donut-like structure called a connexon. When the pores of connexons in adjacent cells align, a channel forms between the cells. Composed of a branching network of strands formed by interacting proteins on opposite cell membranes, with larger numbers of strands making for a tighter seal.
    Function Facilitate cell-to-cell communication and the passage of small molecules between cells. Prevent the leakage of extracellular fluid across epithelial cell layers and maintain the concentration gradient of solutes between cells.
    Size Gap junctions are smaller in size compared to tight junctions. Tight junctions are larger in size compared to gap junctions.
    Permeability Permeable to ions, water, and other substances. Permeability can be regulated, with individual gap-junction channels flipping between open and closed states.
    Role in Tissues Found in tissues containing electrically excitable cells, allowing action potentials to spread rapidly from cell to cell. Crucial in maintaining the concentration gradient of solutes between cells and preventing leakage of extracellular fluid.

    In summary, gap junctions facilitate communication and the passage of small molecules between cells, while tight junctions function as barriers between cells and regulate the movement of water and solutes.

    Read more:

    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.