Question

Where are Zonula adherens found?

Answer 1

Hint: Zonula adherens is a complex protein structure that is found in cell junctions. Cell junctions are actually contact points between the plasma membranes of tissue cells. The five important types of cell junctions are: tight junctions, adherens junction, desmosomes, hemidesmosomes, and gap junctions.

Complete answer:
The cell junctions are very much common in the epithelial tissues. Zonula adherens are common in the skin layers and other epithelial tissue regions. As the name suggests, this cell junction primarily helps in adhesion of the different cells to keep them together.
Zonula adherens or simply adherens junction contain a dense layer of proteins on the inside of the plasma membrane that attaches both to membrane proteins and also to the microfilaments of the cytoskeleton. This dense layer is known as plaque. The transmembrane proteins called cadherins are the ones that join the adjacent cells together.

Each cadherin inserts into the plaque from the opposite side of the plasma membrane, partially crosses the intercellular space (the intercellular space is the space that occurs in between two adjacent cells), and connects to the cadherins of the adjacent cell.
In epithelial cells, especially in the skin and the alimentary canal, adherens junctions form extensive zones called adhesion belts because they encircle the cell similar to the way a belt is worn encircling our waist region.
These junctions mainly help to prevent separation during various contractile and strenuous activities like movement of legs, peristalsis, etc.

Note:
Zonula adherens are thus also known as adherens junction. Both represent the same type of cell junction but are often confused as two different types.
Adherens junctions are also of various types like punctum adherens junction, zonula adherens, and tricellular adherens junction as shown below. The simplest one is specifically termed as zonula adherens.