Microbes and Diseases Flashcards
Microbes…
tiny living things (microorganisms) that are found all around us and are too small to be seen by the naked eye
Disease…
a disorder of structure or function of an organism that is not a direct result of physical injury
Bacteria…
a single cell microorganism (microbe)
some bacteria cause disease
Virus…
an infectious microbe consisting of a segment of nucleic acid (either DNA or RNA) surrounded by a protein coat
smaller than bacteria
they reproduce by infecting a host cell which can cause disease.
White blood cell…
type of cell found in the blood that defends the body against disease and infection
They are attracted towards the infective agents, then surround and engulf them.
Once inside the cell, these white cells then release chemicals that break the organism down and destroy it.
Other white cells, called lymphocytes, target attacks in another way, by making antibodies.
Vaccination…
a vaccine may contain a dead or inactive form of a bacteria or virus that causes disease or a small amount of the toxin produced by the bacteria
this stimulates white blood cells to produce antibodies and/or antitoxins that can fight the infection
It does not contain enough toxin give the person the disease
If the person is later infected by the bacteria/virus, their white blood cells will recognise it and produce antibodies/antitoxins more rapidly to help fight the infection and stop them from becoming ill. – This happens through memory cells
Difference between bacteria and a virus…
bacteria are single cells that can survive on their own, inside or outside the body whereas viruses cause infections by entering and multiplying inside the host’s healthy cells
