Chapter 21, Problem 1A

Interpretation Introduction

Interpretation:

The element present in the human body in largest percentage by mass needs to be determined. Ten other essential elements to life must be written with their used in the body.

Concept Introduction:

Essential elements to life are those which are required by our body in large amount.

Oxygen, hydrogen, carbon and nitrogen are four elements which are present in human body in largest amount by mass.

Answer to Problem 1A

Oxygen is present in the human body in largest percentage by mass.

Ten other essential elements to life are listed below along with their uses in the body.

Carbon-It is the main component of bone, teeth, amino acids, nucleic acids etc.

Hydrogen-It is one of the elements of water required for all the cellular biochemical processes.

Nitrogen-It is one of the components of protein as well as nucleic acids.

Calcium-It forms bone and teeth.

Phosphorous-It is a major component of phosphate group of nucleic acids.

Potassium-It controls the blood pressure.

Sodium-It controls the blood pressure and involved in ion-channel receptors.

Sulfur-It is one of the components of amino acids like cysteine, cystine and methionine.

Magnesium-It is involved in phosphorylation reactions of nucleic acid.

Chlorine-It is used for hydrochloric acid formation used for digestion of food in stomach.

Explanation of Solution

Out of the four major elements of human body as per percentage by mass, oxygen is the most abundant. The percentage mass of oxygen in human body is 65 % out of which 60 % is present as water.

Percentage mass of C, H and N in human body are 18 %, 10 % and 3 %.