Glossary

Microbial terminology explained

Aerobic respiration

The chemical process in cells and tissues, by which organisms obtain energy. Aerobic means that the respiration takes place using oxygen.

Alga (algae, plural)

A single-celled or multicellular eukaryotic, photosynthetic organism.

Amino acid

The basic building block of a protein.

Antibiotic

A chemical that kills or inhibits the growth of bacteria and is used to treat bacterial infections.

Antibody

A Y-shaped protein made by certain white blood cells which is produced by the body’s immune system in response to a foreign substance (antigen). The antibody destroys the antigen.

Antigen

A foreign substance such as a pathogen that stimulates the body’s immune system to produce antibodies.

Archaean (archaea, plural)

A prokaryotic, single celled organism.

Bacterium (bacteria, plural)

A prokaryotic, single celled organism.

Binary fission

A type of asexual reproduction in which the cell divides into two separate daughter cells each with identical DNA.

Biogas

A gas that is produced from the anaerobic (without oxygen) decomposition of organic matter.

Bioremediation

The use of microbes to break down toxic or unwanted substances.

Budding

A type of asexual reproduction in which an outgrowth forms from the parent cell. It then usually pinches off to form a separate independent cell.

Capsid

The protein coat surrounding a virus.

Cell

The basic unit of all living things.

Chlorophyll

A green photosynthetic pigment usually found in organelles called chloroplasts.

Chromosome

A long continuous pieces of DNA that carries genetic information.

Cilium (cilia, plural)

A tiny hair-like structure on the surface of some micro-organisms or cells which beats rhythmically to either propel trapped material out of the body, for example in the lungs, or make a free-living microbe move.

Decomposer

The name given to some fungi and soil bacteria that break down dead animals and plants and their waste products into simpler substances called nutrients.

DNA

Deoxyribonucleic acid: the store of genetic information inside living cells and many viruses.

Enzyme

A protein that facilitates a biochemical reaction by speeding up the rate at which it takes place within cells.

Eukaryote

A single-celled or multicellular organism which has a true membrane-bound nucleus and membrane bound organelles.

Extremophile

A microbe that positively thrives in environments that would kill other organisms.

Fermentation

The conversion of organic compounds such as carbohydrate into simpler substances by microbes, usually under anaerobic conditions (with no oxygen present). Energy is produced.

Flagellum (flagella, plural)

A long thin appendage present on the surface of some cells such as bacteria and protoctista which enables them to move.

Food poisoning

Any illness caused by eating food contaminated by pathogenic microbes.

Food spoilage

Changes in appearance, flavour, odour, and other qualities of the food due to microbial growth which causes it to deteriorate and spoil by decay.

Fungus (fungi, plural)

A eukaryotic, non photosynthetic, spore forming organism. They range from single celled organisms to very complex multicellular organisms.

Gene

Basic unit of inheritance located on a chromosome. A gene is a piece of deoxyribonucleic acid (DNA) that contains the instructions for the production of a specific protein.

Generation time

The time taken for a population of micro-organisms to double in number.

Global warming

A rise in the temperature of the Earth’s atmosphere due to the increased emission of greenhouse gases which traps more heat in the atmosphere, causing the planet to warm up.

Host cell

A cell that is infected by a virus or another type of micro-organism.

Hypha (hyphae, plural)

A very fine thread that is the basic structure of filamentous fungi.

Inflammation

A reaction of tissue to irritation, injury, or infection. It is a beneficial process as it destroys or contains the pathogen within a small area enabling the healing process to begin.

Lymphatic system

Lymph nodes linked by a network of small tubes spread throughout the body that transport the lymph fluid.

Lysis

The physical rupture of a cell

Memory cell

A cell which is produced as part of a normal immune response. These cells remember a specific antigen and are responsible for the rapid immune response, production of antibodies, on exposure to subsequent infections by that particular antigen.

Methanogen

Micro-organism that produces methane.

Micro-organism (microbe)

A small living thing. The group includes bacteria, archaea, protozoa, algae, fungi and viruses.

Mould

A multicellular filamentous fungus.

Mycelium

A branched network of fungal hyphae.

Normal body flora

Microbes that have adapted to living on the body, are usually present and rarely cause home.

Nucleus

The nucleus is the control centre of the cell containing chromosomes.

Organelle

A membrane enclosed structure, in cells, that has a specialised function.

Pathogen

An organism that causes disease.

Phagocyte

A white blood cell that can surround engulf (by phagocytosis) and destroy invading micro-organisms including viruses and bacteria. There are two separate groups - macrophages and neutrophils.

Photosynthesis

A process that occurs in plants, algae and some bacteria called the cyanobacteria that traps the sun’s light energy and uses it to fix carbon dioxide into organic compounds.

Primary producer

Green plants, algae and some bacteria called the cyanobacteria which produce their own food by a process called photosynthesis. They are found at the beginning of the food chain.

Prokaryote

An organism that has a simple cell structure without a membrane bound nucleus or organelles.

Protein

A folded long – chain molecule consisting of amino acids. Each protein has a special function. Proteins are required for the structure, function, and regulation of an organism’s cell/cells, tissues, and organs.

Protozoan (protozoa, plural)

A eukaryotic, single celled organism that usually lacks chlorophyll.

Pseudopodium (pseudopodium, plural)

A temporary extension of the cytoplasm of an amoeboid cell. It is used in both motility and feeding.

Recycling

A cyclical process by which essential elements are released into the environment where they are then reused.

Sporangium (sporagia plural)

A sac containing spores that develops from the fruiting body of a fungus.

Spore

A general term for a dormant stage in an orgainisms life cycle. Spores enable survival of adverse conditions, distribution, and reproduction. There are many types which may be produced both asexually and sexually.

Toxin

any substance that is poisonous to other organisms

Vaccine

A special type of medicine that is given to both people and animals to artificially increase immunity to a particular disease and to prevent an infectious disease from developing.

Viral envelope

A spikey coat that covers the virus’s protein coat or capsid.

Virus

An infectious particle that relies on the cellular machinery of the host cell to grow and replicate.

Yeast

A single-celled fungus.