Question

A phosphoglyceride is always made up of
a. Only a saturated fatty acid esterified to a glycerol molecule to which a phosphate group is also attached
b. Only an unsaturated fatty acid esterified to a glycerol molecule to which a phosphate group is also attached
c. A saturated or unsaturated fatty acid esterified to a glycerol molecule to which a phosphate group is also attached,
d. A saturated or unsaturated fatty acid esterified to phosphate group which is also attached to a glycerol molecule.

Answer 1

Hint: Phosphoglyceridies are also called as glycerophospholipids, to say simply, this are glycerol based phospholipids, and this phosphoglyceridies are very important components of the biological membrane. They contain one alkyl or acyl group with residue glycerol moiety.

Complete answer:
> Structure of phosphoglyceridies
- In phosphoglyceridies, the alcohol that is present is glycerol, to which two fatty acid chains are attached along with phosphoric acid as esters.
- The two fatty acid chains that are attached to glycerol are nonpolar, and it is hydrophobic.
- While phosphate is attached to 3rd carbon of the glycerol, which is hydrophilic.
- Both hydrophobic and hydrophilic nature make this amphipathic.
- Both of the layers are arranged as bilayers.
- The polar hydrophilic head is present outside towards the aqueous side.
- While a non polar hydrophobic tail is present towards the inwards.

> Functions of phosphoglyceridies
- These are structural components of all biological membranes or cell membranes.
- The amphipathic nature of the phosphoglyceridies helps to form the lipid bilayer, and makes the structure of the membrane.
- Cell membranes when we see under an electron microscope, it consists of two types arranged in two rows.
- This is different in different types of cells
- Apart from forming the structural membrane, these phosphoglycerides also have other functions which include, signal induction and transport.
- This phosphoglyceridies provide the precursors for the synthesis of prostaglandins, and leukotriens.
- These are the storage centers for the secondary messengers.
- This is used for the emulsification process.

Hence, the correct answer is option (C).

Note: One of the example for phosphoglyceride is plasminogen, in this first carbon of glycerol has hydrocarbon attached to it by either, 2nd carbon has fatty acid chain linked by the ester, and 3rd carbon linked to an ethanolamine by phosphate ester.