Question

Why is the enzyme, cellulase needed for isolating genetic material from plant cells and not from the animal cells?

Answer 1

Genetic materials of an organism are those materials found in nucleus and mitochondria. They play a fundamental role in determining the traits and characteristics of the cells. The genetic material can be either $DNA$ or $RNA$.

Complete answer:
To isolate the genetic material, the cell wall must be broken to release the contents inside the cell. The key difference between animal and plant cells is in their cell wall. The animal cell lacks a cell wall and has only a plasma membrane, which is semi-permeable. But, plant cells have cell walls and plasma membranes made of cellulose which protects the cell. The presence of cellulose makes it rigid and impermeable for anything to pass through. Cellulose is a straight chain polymer with a linkage. Hence, when the genetic material of a plant cell is to be isolated, cellulose enzymes can be used to break open the cell. The cellulase enzyme catalyses cellulolysis, which is a process in which cellulose is broken down into smaller polysaccharides.

Note: The genetic material from plant cells is isolated as follows:
-First, the cell wall of the cell needs to be digested using enzyme cellulase. This releases the cytoplasm outside along with the genetic material.
-The cell debris and proteins are removed by using surfactants like $SDS$and by using protease enzymes respectively. If $DNA$ is the molecule of interest RNase is used to remove$RNA$, otherwise $DNase$ is used to remove $DNA$.
-A salt solution (saline) is used to clump all the debris and is removed through centrifugation.
-The histone proteins can then be removed by subjecting the $DNA$ sample to protease.
-The $DNA$ finally isolated is stored in the$TE$buffer, which is a slightly alkaline solution.