Question

Draw Singer and Nicholson’s model of cell membrane

Answer 1

Answer:

The cell wall is present only in plants, fungi, and bacteria. The image above represents a plant cell wall

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=

• Protecting the cell against physical damage and invading pathogens.

• Regulate and controls the direction of cell growth.

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

• Functions as a storage unit by storing carbohydrates for use in plant growth, especially in seeds.

• It acts as a selectively permeable membrane by allowing the entry of small molecules to pass through it.

Answer 2

Dear Student,

● Singer and Nicholson’s model of cell membrane -

• It is also known as fluid mosaic model.
• According to this, cell membrane is made of phospholipid bilayer with hydrophilic and hydrophobic end.
• It has two types of proteins - integral proteins and transmembrane proteins.
• Cell memane is not rigid but is flexible and adaptable to changing environment.

Thanks dear. Hope this helps you...