Question

Who proposed the fluid mosaic model of plasma membrane?
A. Camillo golgi
B. Schledien and Schwann
C. Singer and Nicolson
D. Robert brown

Answer 1

Hint: The fluid mosaic model membrane model of membrane structure was proposed in the year 1972 based on thermodynamic principles of organisation of membrane lipids and proteins and available evidence of asymmetry and lateral mobility within the membrane matrix.

Complete answer:
The fluid mosaic model was first proposed by singer and Nicolson in 1972 which explains the structure of the plasma membrane. The fluid mosaic model describes the structure of the plasma membrane as a mosaic of components which includes phospholipids, cholesterol, proteins and carbohydrates –that gives the membrane a fluid character. Plasma membranes range from 5-10 nm in thickness. The proportions of proteins, lipids, and carbohydrates in the plasma membrane vary a lot within cell type and membrane. For example, myelin contains about 18% of protein and 76% of lipid. The mitochondrial inner membrane which contains 76% protein and 24% lipid.

The main fabric of the membrane is composed of amphiphilic or dual –loving, phospholipids molecules.
Integral proteins, the second major component of plasma membrane, are integrated completely into the membrane structure with their hydrophobic membrane spanning regions interacting with the hydrophobic region of the phospholipid bilayer.
Carbohydrates, the third major component of plasma membrane, are always found on the exterior surface of cells where they are bound either to proteins (forming glycoproteins) or to lipids ( forming glycolipids).
Functions of the plasma membrane: it acts as a physical barrier, Endocytosis and exocytosis, Selective permeability and Cell signalling

So, the correct answer is option C.

Note:
Camillo golgi: the existence of the cell organelle which is now known as golgi apparatus or golgi complex or simply as the golgi.
Schleiden and Schwann: These both were studying tissues and proposed the unified cell theory. Robert Brown was responsible for discovering the nucleus of a cell.