Cell Membrane

Question 1

also called plasma membrane is a biological membrane separating the interior of a cell from the outside environment.

Answer 1

Cell membrane

Question 2

regulates the flow of materials into and out of cell-selectively permeable. Selective Permeability - it allows some substances to cross it more easily than others.

Answer 2

Function of cell membrane

Question 3

Four major classes are commonly present in cell membrane.

Phospholipids (most abundant), spingolipids, glycolipids, and sterols (e.g., cholesterol). All of them are amphipathic

Answer 3

Lipids

Question 4

Contains hydrophobic tails buried in the interior of the membrane and the hydrophilic head groups exposed on both sides, in contact with water. (Most abundant)

High concentration of cholesterol may increase the rigidity and decrease the flexibility of the membrane, affecting membrane protein movement and function.

Answer 4

Phospholipid

Question 5

Cell membrane contains about 50% of this

Answer 5

Protein

Question 6

Permanently attached to cell membrane

Embedded in the whole membrane

Contain both hydrophobic and hydrophilic parts

Answer 6

Integral (intrinsic) protein

Question 7

Temporarily attached to cell membrane

Loosely bound to the surface of the membrane

Contain hydrophilic parts

Answer 7

Peripheral (extrinsic) protein

Question 8

present in exterior or polar end of phospholipids at the external surface of plasma membrane.

Answer 8

Carbohydrates

Question 9

developed by cell biologists, Seymour Jonathan Singer and Garth L. Nicolson in 1972

describes the structure of the plasma membrane as a mosaic of components - including phospholipids, cholesterol, proteins, and carbohydrates that gives the membrane a fluid character.

Answer 9

Fluid mosaic model