Question

Which one of the following biomolecules is correctly characterized?
A. Palmitic acid – an unsaturated fatty acid with 18 carbon atoms.
B. Adenylic acid – adenosine with a glucose phosphate molecule.
C. Alanine amino acid – contains an amino group and an acidic group anywhere in the molecule.
D. Lecithin – a phosphorylated glycerine found in the cell membrane.

Answer 1

Hint: The bio-molecules are those molecules that are produced by the living organism. Some of them do not involve in the activity but provide structure like lipids in the cell membrane.

Complete step by step answer: Our body consists of thousands of biomolecules. These are those compounds that are involved in various metabolic processes of our body. Some of the biomolecules do not take part in metabolism rather they act as structural units for various biological units.
Let us study each given bio-molecules one by one to know if they are characterized correctly or not.
Palmitic acid: The palmitic acid is a saturated fatty acid that means that its molecules have single bonds between them. It is obtained from palm oil majorly. It can also be found in various plants and animals. The chemical formula for palmitic acid is \[C{{H}_{3}}{{\left( C{{H}_{2}} \right)}_{14}}COOH\]. Thus, it is not unsaturated and has 16 carbon atoms.
Adenylic acid: It is a nucleotide that is found in RNA or Ribonucleic acid. It is an ester of the nucleoside adenosine and phosphoric acid. It is also called Adenosine monophosphate or $5'$-adenylic acid. Thus, adenylic acid is an adenine with a phosphate group and ribose sugar.
Alanine amino acid: It is also called the L-isomer. It is one of the 20 amino acids that are encoded by genetic code. Codons GCU, GCA, GCC, and GCG translate to alanine. It is a non-polar amino acid. The chemical formula of Alanine is \[C{{H}_{3}}CH\left( N{{H}_{2}} \right)COOH\].
Lecithin: It is the major constituent of the phospholipid part of the plasma membrane or cell membrane of the cell.
Therefore, the right answer is option D.

Note: Lecithin is a very attractive class of fatty substances. They are generally yellowish-brown in color and are found in plant and animal tissue. They are attracted to both water and fatty substances. They have various uses in food texturing, emulsifying, etc.