Question

Both lysosomes and vacuoles are endomembrane structures, yet they differ in terms of their functions, comment.

Answer 1

Hint: Both lysosomes and vacuoles are endomembrane structures, but the vast difference is seen in their function. One of them helps in storage while the other helps in the digestion of worn-out cells and any foreign substance.

Complete step by step answer:
The Endomembrane system is defined as a system of membranes within a cell that serves as a single functional and developmental unit. Both lysosome and vacuole come under endomembranous structures.

Lysosomes serve two major functions:
- Intracellular Digestion:
The food has to be digested for which the lysosome membrane fuses with the membrane of food vacuole and squirts the enzymes inside.
The digested food is then diffused through the vacuole membrane and enters into the cell to be used for energy and growth.
- Autolytic Action:
 In this, the cell organelles that require to be destroyed are covered by vesicles or vacuoles by the method of autophagy to make autophagosomes.
The autophagosome is then finally destroyed by the action of lysosomal enzymes.
A vacuole is a membrane- bound organelle that is present in all plant and fungal cells and some of the protist, animal, and bacterial cells also.
- Plant vacuoles can store many varieties of molecules. It can act as a storage organelle for both nutrients and waste products.
- In seeds, stored proteins which are needed for germination are kept in ‘protein bodies’, which are a type of modified vacuoles.
- The vacuole has a crucial homeostatic function in plant cells that are subjected to wide variations in their environment. For instance, when the pH within the environment drops, the flux of H+ into the cytoplasm is buffered by the increased transport of ${ H }^{ + }$ into the vacuole.

Note: Lysosome plays a crucial role in fertilization. The acrosome which is present in the sperm head is a lysosome that ruptures and releases enzymes on the surface of the egg. This helps and clears the way for sperm entry into the egg by digesting the egg membrane.