Question

What is the endoplasmic reticulum made up of?

Answer 1

Endoplasmic reticulum:

1. The ER (Endoplasmic reticulum) is present in almost all eukaryotic cells.
2. A few cells, such as ova, embryonic cells, and mature red blood corpuscles, however, lack ER.
3. The ER is often an extensive, 3-dimensional network of intracellular membranes.
4. It is formed of three types of elements: Cisternae, tubules, and vesicles.

1. Cisternae-

1. These are flattened, unbranched, sac-like elements.
2. They bear ribosomes on the surface and therefore appear rough.

2. Tubules-

1. These are irregular branching element that forms a network along with other elements.
2. They are often free of ribosomes.

3. Vesicles-

1. These are oval or rounded, vacuole-like elements.
2. They often occur isolated in the cytoplasmic matrix.
3. They are free of ribosomes.