Chapter 6.2, Problem 7ELO

Summary Introduction

To determine:

The functions of capsids, nucleocapsids, envelops and spikes.

Introduction:

Viruses are much smaller and simpler than prokaryotic cells and are responsible for some of the most virulent as well as common diseases on Earth. They cannot be seen by ordinary microscopes and are not considered to be alive until they enter a host cell. They comprise of a core of nucleic acid (DNA or RNA) covered by a protective layer of proteins called capsid. Typically, viruses consist of a core of nucleic acid (DNA or RNA) and a protective coating of proteins, called capsid. Together, the nucleic acid and capsid form the nucleocapsid. Viruses that contain only nucleocapsid are called naked viruses. Viruses with an additional layer of membranous coating are called enveloped viruses.