Glossary

Microbial terminology explained

• A - D
• E - H
• I - N
• O - S
• T - Y

• A

  • Aerobic respiration

    Information and advice on all aspects of microbiology teaching - both theory and practice is just a click away.

  • 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.

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• B

  • 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.

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• C

  • 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.

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• D

  • DNA

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

  • 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.

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• E

  • 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.

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• F

  • 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.

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• G

  • 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.

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• H

  • 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.

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• I

  • 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.

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• L

  • 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.

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• M

  • 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.

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• N

  • 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.

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• O

  • Organelle

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

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• P

  • 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.

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• R

  • Recycling

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

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• S

  • 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.

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• T

  • Toxin

    Any substance that is poisonous to other organisms.

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• V

  • 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.

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• Y

  • Yeast

    A single-celled fungus.

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