Question

What is a secondary lysosome?

Answer 1

Lysosomes were discovered by the Belgian biochemist Christian de Duve in 1955. These are small spherical vesicles that measure around 500 nm. Their function is intracellular digestion and it contains enzymes that are required to digest all types of macromolecules.

Complete answer-
Let us garner some information about lysosomes to answer this question. We have already discussed that it contains enzymes, these enzymes that are present in the vesicles belong to the hydrolase class, which are quite active in the acidic condition. This acidic condition is maintained by pumping protons into the interior of lysosomes.
Lysosomes are basically of two main types- primary lysosomes and the secondary lysosome. The secondary lysosomes are formed when the primary lysosome combines with pinosomes or phagosomes or endosomes. This fusion causes the activation of the previously inactivated enzyme and makes it capable of digestion of biomolecules such as nucleic acids, lipids and others.
In comparison with the primary lysosomes, secondary lysosomes are large in size and release enzymes outside the cells where the degradation of foreign material takes place. Most of the lysosomal enzymes function inside the acidic environment and so are known as the acid hydrolases. These contain around 45 enzymes that are grouped in six categories which are – nucleases, proteases, glycosidases, phosphatases, lipases and sulphatases.

Note:
Lysosomes is the name that is derived from Greek word lysis that means to destroy or dissolve and soma meaning body. Lysosomes vary in plant cell and animal cell, the former usually contains a single large lysosome whereas the later may contain numerous lysosomes.