Give the chemical composition and functions …

The cell wall is the outermost covering of plant cells. It is present outside the cell membrane and is tough, flexible and sometimes rigid in its texture. It is mainly composed of cellulose,  long fibres of carbohydrates including hemicellulose, lignin, and pectin.

The main functions of the cell wall

1. Protecting the cell against physical damage and invading pathogens.

2. Regulate and controls the direction of cell growth.

3. Providing the strength, structural support and maintaining the shape of the cell

The cell membrane is also known as the plasma membrane. It is the outermost covering of animal cells. It is a semi-permeable membrane composed of lipids and proteins. The main functions of the cell membrane include:

1. Protecting the integrity of the interior cell.

2. Providing support and maintaining the shape of the cell.

3. Helps in regulating cell growth through the balance of endocytosis and exocytosis.