Learning Objects : Lifelong Application

RLO: Bacteria and Viruses Compared

Resources

Title/link	Description
Dixon, B (1994) A rampant non-epidemic, BMJ 308:1567-1577.	Sets out the facts ignored by the media in their coverage of the 'superbug'.
National Institute of Allergy and Infectious Diseases, Microbes in sickness and in health	Describes the various types of microbes and explains their effects on people.

Glossary

Antibiotic: A drug used to treat some bacterial diseases.

Bacteria: Microscopic organisms composed of a single cell, and lacking a defined nucleus and membrane-enclosed internal compartment.

Disease: A state in which a function or part of the body is no longer in a healthy condition.

DNA (deoxyribonucleic acid): A complex molecule found in the cell nucleus which contains an organism's genetic information.

Epidemic: A disease outbreak that affects many people in a region at the same time.

Genes: Units of genetic material (DNA) that carry the directions a cell uses to perform a specific function.

Genome: All of an organism's hereditary information, which is encoded in the DNA (or, for some viruses, in the RNA).

Gram-negative: Refers to bacteria that do not retain crystal violet dye in the Gram staining protocol. Many species of Gram-negative bacteria are pathogenic, meaning they can cause disease in a host organism.

Human immunodeficiency virus (HIV): The virus that causes AIDS.

Immune system: A complex network of specialised cells, tissues and organs that defends the body against attacks by disease-causing microbes.

Immunisation: Vaccination or other process that induces protection (immunity) against infection or disease caused by a microbe.

Infection: A state in which disease-causing microbes have invaded or multiplied in body tissues.

Infectious diseases: Diseases caused by microbes that can be passed to or among humans by several methods.

Microbes: Microscopic organisms, including bacteria, viruses, fungi, plants and animals.

mRNA (messenger ribonucleic acid): A molecule of RNA encoding a chemical 'blueprint' for a protein product. mRNA is transcribed from a DNA template, and carries coding information to the site of protein synthesis: the ribosomes.

Pathogens: Disease-causing organisms.

RNA (ribonucleic acid): A complex molecule that is found in the cell cytoplasm and nucleus. One function of RNA is to direct the building of proteins.

tRNA (transfer ribonucleic acid): A small RNA chain that transfers a specific amino acid to a growing polypeptide chain at the ribosomal site of protein synthesis during translation.

Virulent: Refers to having the ability to cause and spread disease.

Virus: Minute particle capable of replication, but only within living cells. Many viral diseases are controlled by vaccination.

Image information

Image of S. pyogenes made available by the Public Health Image Library of the Centers for Disease Control and Prevention.
Image of a bacteriophage used under the terms of the GNU Free Documentation License.