Question

Most abundant organic compound on earth is
A. Cellulose
B. Protein
C. Lipids
D. Steroids

Answer 1

Hint:These are mostly found in plants. The cell wall in plants consists of this tough material. They provide structural support to plants. The bonds between each cellulose molecule are very strong, which makes cellulose very hard to break down.

Complete answer:
Carbon forms the component of all living organisms. Life on earth is thus said to be carbon-based. The compounds that contain carbon are known as organic compounds.

The most abundant organic compound on Earth in terms of chemical class is the carbohydrate, one of the macromolecules. Carbohydrates are compounds composed of carbon, hydrogen, and oxygen. Carbohydrates are grouped into monosaccharides, disaccharides and polysaccharides. Cellulose, a storage form of carbohydrate found in plants that humans cannot digest, is among the most plentiful of the carbohydrates worldwide.

Proteins are the building blocks of life. They are made of small carbon compounds called amino acids. Amino acids are made up of carbon, oxygen, nitrogen, hydrogen and sometimes sulphur. All amino acids have the same general structure. Proteins are made up of a combination of about 20 amino acids.

Lipids are molecules made mostly of carbon and hydrogen that make up the fats, oils and waxes. Lipids are composed of fatty acids, glycerol and other components. The primary function of lipids is the storage of energy.

Steroids are a class of lipids. A steroid is a type of organic compound that comprises a characteristic arrangement of four cycloalkane rings that are joined together. Steroids include well-known compounds such as cholesterol, sex hormones, cortisone, and anabolic steroids.

Thus, the correct answer is option A i.e., Cellulose.

Note:Cellulose is a polymer of linear polysaccharide, with several monosaccharide glucose units. The acetal linkage is beta which distinguishes it from starch. This unique variation in acetal bonding results in a substantial difference in human digestibility. Human beings are unable to digest cellulose because there are no sufficient enzymes for breaking down beta-acetal linkages.