Question

Select the correct statement from the following regarding cell membrane

• A. $Na^+$ and $K^+$ ions move across cell membrane by passive transport
• B. Proteins make up 60 to $70\%$ of the cell membrane
• C. Lipids are arranged in a bilayer with polar heads towards the inner part
• D. Fluid mosaic model of cell membrane was proposed by Singer and Nicolson

Answer 1

Answer: (D)

Fluid mosaic model of cell membrane was proposed by Singer and Nicolson

Answer 2

According to the fluid mosaic model of cell membrane structure proposed by Singer and Nicolson (1972) plasma membrane contains about 50-60% proteins and 50^0% lipids. Lipids form a bilayer with hydrophilic heads pointing outwards. Cell membrane allows transport of some molecules by passive transport e.g., water, neutral solutes while some are transported actively e.g., Na+/K+ pump.