what is lecithin with regard to its chemical structure

Options

A. Type of wax
B. Phospholipid
C. Oil have low melting point and hence remain as oil in winters
D. Simple fatty acid

Answer

**Step-by-Step Solution:**

1. **Definition of Lecithin**: Lecithin is a type of phospholipid, which is a class of lipids that are a major component of all cell membranes.

2. **Chemical Structure**: Lecithin consists of a glycerol backbone that is esterified to two fatty acids and one phosphate group.

3. **Fatty Acids**: In lecithin, there are two fatty acid chains attached to the glycerol. These fatty acids are hydrophobic (water-repelling) and contribute to the non-polar characteristics of the molecule.

4. **Phosphate Group**: The third position of the glycerol is occupied by a phosphate group. This phosphate group is hydrophilic (water-attracting), which means it interacts well with water.

5. **Additional Group**: Often, the phosphate group in lecithin is further linked to a nitrogenous group, such as choline. This additional group enhances the hydrophilic nature of the molecule.

6. **Amphipathic Nature**: Due to the presence of both hydrophobic fatty acid tails and a hydrophilic head (phosphate and nitrogenous group), lecithin exhibits an amphipathic structure. This property is crucial for its role in forming cell membranes.

7. **Conclusion**: Therefore, lecithin is characterized by its phospholipid structure, which includes two fatty acids, a phosphate group, and a nitrogenous group, making it essential for biological membranes.