Pectin, which is responsible for the firmness and softness of fruits, is mainly composed of which acid unit?

Correct option is B

The correct answer is (b) Galacturonic acid.
 Galacturonic acid is the main component of pectin, a structural polysaccharide found in the cell walls of plants.
 Pectin consists of a linear chain of galacturonic acid units, which are linked by α-(1→4)-glycosidic bonds.
 The presence of pectin in fruits is responsible for their firmness and ability to form gels, which is why it is commonly used in the food industry for making jams and jellies.
Information Booster:
 Aspartic Acid:
o An amino acid used in the biosynthesis of proteins.
o It is one of the 20 standard amino acids used by cells in protein synthesis.
 Lactic Acid:
o An organic acid produced in muscles during strenuous exercise due to anaerobic respiration.
o It is also used in the food industry, particularly in dairy products like yogurt.
 Glutamic Acid:
o An amino acid that functions as a neurotransmitter in the brain.
o It is also used as a flavor enhancer in the form of its sodium salt, monosodium glutamate (MSG).