Biology · Biomolecules · NEET
Lecithin is a PHOSPHOLIPID, not a glycolipid. NCERT clearly names lecithin as an example of a phospholipid found in the cell membrane. A glycolipid contains a sugar group, but lecithin contains a phosphorus group. NEET 2022 tested exactly this: the statement 'Lecithin found in the plasma membrane is a glycolipid' was marked WRONG. Remember: Phospho-lipid, not sugar-lipid.
No. Lecithin is NOT a secondary metabolite. It is a phospholipid, which is a primary lipid of the cell membrane. NEET 2023 asked 'Which is NOT a secondary metabolite?' and the answer was Lecithin, because anthocyanin, curcumin, and morphine are secondary metabolites but lecithin is a structural membrane lipid.
A lipid becomes a phospholipid when it contains phosphorus and a phosphorylated organic compound. Simple lipids (like fats and oils) have only glycerol and fatty acids. Phospholipids add a phosphate group, which is why they can form the cell membrane. This phosphate part is why lecithin differs from a plain glyceride.
Phospholipids are found in the cell membrane (also called the plasma membrane). They form the main lipid layer of every cell membrane. This is a very common NEET fact: if a question links a membrane lipid to a name, the answer is usually lecithin, a phospholipid.
NCERT calls lecithin a small molecular weight organic compound found in living tissues, even though lipids are placed in the acid-insoluble (macromolecular) fraction during analysis. NEET 2024 asked about 'Lecithin, a small molecular weight organic compound' and the answer was Phospholipids. So by molecular weight it is small, but by fraction it sits with macromolecules.
Lecithin, a small molecular weight organic compound found in living tissues, is an example of:
Which of the following is not a secondary metabolite?
Following are the statements with reference to 'lipids'. (a) Lipids having only single bonds are called unsaturated fatty acids. (b) Lecithin is a phospholipid. (c) Trihydroxy propane is glycerol. (d) Palmitic acid has 20 carbon atoms including carboxyl carbon. (e) Arachidonic acid has 16 carbon atoms. Choose the correct answer.
Try the real previous-year questions from this chapter — each with the answer and a full solution.
A phospholipid is a lipid that contains a phosphorus group (a phosphorylated organic compound). This phosphate part lets it build the cell membrane. Lecithin is the NCERT example you must remember for NEET.
Lecithin appears again and again in NEET as the standard example of a phospholipid and a membrane lipid. Recent NEET papers (2021, 2023, 2024) all tested it. Knowing 'lecithin = phospholipid = cell membrane' can directly fetch a mark.
A simple fat or glyceride has only glycerol and fatty acids. A phospholipid also contains a phosphate group. This extra phosphate is why phospholipids build membranes while plain fats mainly store energy.
Lecithin is found in living tissues in general, including both plant and animal cell membranes. NCERT describes it simply as a small molecular weight organic compound and a phospholipid of the cell membrane.
