Question

The correct order of chemical composition of living tissues/cells in term of percentage of the total cellular mass is
A. Nucleic acids > proteins > $H_{2}O$ > carbohydrates > ions > lipids
B. $H_{2}O$> proteins > Nucleic acids > carbohydrates > lipids> ions
C. $H_{2}O$> proteins > carbohydrates> Nucleic acids> lipids> ions
D. lipids> ions > carbohydrates > $H_{2}O$> proteins > Nucleic acids

Answer 1

Hint: Various degrees of organization are exhibited by life. Atoms are combined to form molecules, molecules, are fused to form organelles and all organelles together form a cell. A living cell is made up of various constituents such as water, lipids, ions, nucleic acids, and many more.

Complete answer: Cell theory states that all living organisms are made up of cells. A cell is a basic, smallest, and functional unit of life. The existing cells are produced from pre-existing cells. Cells can be further classified as prokaryotes and eukaryotes. Prokaryotic cells are surrounded by a plasma membrane with a characteristic cell wall whose composition may differ depending on the organism. Eukaryotes have distinct nuclei bound by a nuclear membrane. They consist of membrane-bound organelles like the endoplasmic reticulum and mitochondria. The shape and size of cells vary depending upon their function. Depending upon the function the cell regulates, the size and length of the cell vary. Cells are chemically composed of many organic materials, ions, and water. Water accounts for 70 percent or more of total cell mass. It is the most abundant molecule in the cell. Proteins are macromolecules and each cell consists of thousands of different proteins. It holds 10 to 15 percent of total cell mass. Nucleic acids such as DNA or RNA are present in each cell which act as a carrier of genetic information. Nucleic acid present in each cell is 5 to 7 percent. Carbohydrates in the form of simple sugars hold a total of 3 percent and lipids 2 percent and inorganic ions 1 percent. Therefore the correct sequence of chemical composition in a cell is $H_{2}O$ > proteins > Nucleic acids > carbohydrates > lipids> ions.

So, option B is the correct option.

Note: This chemical composition of the cell is due to the presence of various cell organelles such as the endoplasmic reticulum, mitochondria, and many more. The nucleus of the cell consists of nucleic acid either DNA or RNA.