Chapter 6, Problem 33A

Summary Introduction

To write:

Why hydrogen bonds are so important for living organisms.

Introduction:

Compounds like water, salt, etc., are formed when two substances are combined together. The force that holds the substances together is called a chemical bond. Chemical bonds are of two types- covalent and ionic bonds. Covalent bond is formed by sharing of electrons. An ionic bond results from electrical attraction between two oppositely charged atoms or group of atoms. Substances formed by ionic bonds are called ionic compounds.

Explanation of Solution

Hydrogen is very important for living organisms as it is required for the formation of water molecule. Water is a molecule formed by covalent bonds that link two hydrogen atoms with an oxygen atom. Hydrogen bonding partially determines the structure of proteins. A protein is composed of small carbon compounds called amino acids. Carbon can form four covalent bonds, one of which is with hydrogen. Hydrogen bonds are responsible for holding the strands of DNA together. In nucleic acids such as DNA and RNA, the sugar of one nucleotide bonds with the phosphate of another nucleotide. The nitrogenous base that sticks out from the chain forms hydrogen bonds with other bases in other nucleic acids. Thus, hydrogen bonding is important in many chemical processes.

Conclusion

Hydrogen bonding accounts for the unique solvent capabilities of water. Hydrogen bonds hold together complementary DNA strands, and they are responsible for determining protein structures.