Chapter 13, Problem 1SA

Summary Introduction

To review:

The nonenveloped viruses are more resistant than enveloped viruses to disinfectants.

Introduction:

Viruses are the microscopic infectious agents, which consist of a nucleic acid strand enveloped by a coat of proteins known as the capsid. The nucleic acid particle can be DNA (deoxyribonucleic acid) or RNA (ribonucleic acid). The viruses are considered as nonliving organisms as they are inactive and cannot reproduce on their own and depends on their host’s machinery.

Explanation of Solution

The capsid protects the nucleic acid particle from the actions of chemicals, environment, and digestive enzymes present in the body of the host. The nucleic acid encodes for the various enzymes and other materials needed by the virus for causing the infection in the living cells of the host.

The capsid, present along with the nucleic acid present in it, is known as the nucleocapsid. There are some viral strains found, which consist of a bilipid layer around the nucleocapsid as an envelope. Such viruses are called the enveloped viruses and the viruses without it regarded as the nonenveloped viruses or naked viruses. The envelope consists of spikes that help the viruses to attach to the cell of the host.

Disinfectants are the chemicalsthatare used to kill the microbes and sterilize the material. The enveloped viruses are more prone toward the action of these chemicals than the nonenveloped viruses. This is so because the disinfectants damage the spikes present on the envelope layer and thus inhibits the noninfectious nature of the viruses as they can no more attach to the host’s cells to cause the infection.

Conclusion

Therefore, the nonenveloped viruses are not susceptible to the action of the disinfectants as compared to the enveloped one. This is because the lipid envelope in the enveloped viruses gets destroyed by these chemicals.