Chapter 6, Problem 45A

Summary Introduction

To write:

Why cells contain both macromolecules and small carbon compounds.

Introduction:

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. Carbon can form four covalent bonds with other atoms. These covalent bonds allow carbon to bonds to each other, giving rise to a variety of important carbon compounds. The carbon compounds can exist as straight chains, branched or ring structure. Carbon compounds lead to diversity of life on earth.

Explanation of Solution

Organisms are made of carbon-based molecules. Carbon compounds form the basic building blocks of living organisms. Most cells have small carbon compounds that act as the building blocks for large molecules. Smaller organic molecules join together to form macromolecules or polymers. Polymers are formed by repeating units of nearly identical or identical compounds known as monomers joined by a series of covalent bonds. The biological macromolecules are divided into four major classes - carbohydrates, proteins, lipids and nucleic acids. As all organisms are made up of carbon-based molecules, cells have both macromolecules and small carbon molecules.

Conclusion

Carbon compounds form the basic building blocks of living organisms. Biological macromolecules are formed by small carbon compounds joined to form polymers.