Question

Plasmalemma is made up of
(a) Single-layer of protein
(b) Single lipid layer
(c) Double lipid layers
(d) Single lipid and single protein layer

Answer 1

Hint: The plasmalemma is a thin layer that encloses the cytoplasm of cells. It is required to be fluid and semipermeable in nature. It is also called a cell membrane as it bounds the cell and separates it from the outer environment. It is composed of fats and protein molecules.

Complete answer:
It is made up of two layers of lipid and hence called the bilipid membrane. The lipid molecules are arranged in such a manner that the hydrophilic heads face the outside and the hydrophobic tails are present in the center of the membrane. This arrangement allows fluidity to the membrane.
-Plasmalemma is the membrane that bounds the cell and separates it from the outer environment. It is generally known as the plasma membrane.
-The membrane also has some integral proteins which have specific functions.
1)The transporter protein forms protein channels that allow the molecules to be sent back and forth through the membrane.
2)The integral proteins are present to act as ion channels, protein pumps, etc.
-The plasmalemma also includes carbohydrates out of which glycoproteins make up the majority.
- The cell membrane is involved in other functions like ion conductivity, cell signaling, and cell adhesion
-Plasmalemma is also called Plasma membrane and this term was given by Plower (1931).

So, the correct answer is “Double lipid layers.”

Note:
The various functions of plasma membrane include:
-The basic role of the plasma membrane is to protect cells.
-It also implements a fixed environment inside the cell.
-It transports nutrients into the cell and also transports toxic substances out of the cell.
-The membrane of the cell, which would be the plasmalemma, will have proteins on it that interact with other cells.
-The plasma membrane also provides structural support for a cell.