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Kairen (Parent) April 30 2015
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The body has many ways in which it can protect against pathogens (which are microorganisms which cause disease, such as harmful bacteria or viruses).
White blood cells are key in protecting against pathogens. They ingest the harmful microorganisms (they surround them and take them up - a bit like eating them, but you must use the word ingest).
Pathogens can produce harmful chemicals called toxins, and white blood cells produce antitoxins to destroy these.
Certain white blood cells called lymphocytes are responsible for producing the antibodies which destroy specific pathogens by detecting antigens (foreign chemicals released by the pathogen). Antibodies can bind to pathogens and damage/destroy them, or clump them together for easy ingestion by another type of white blood cell, the phagocyte.see more
Ionic bonding occurs when transfer of electrons takes place. One atom (or molecule) donates one or more electrons to another. Since electrons have a negative charge, this leaves the donating atom electron deficient (+ve charged ion) and the other atom electron rich ( -ve charged ion). The ions then attract each other through electrostatic forces of attraction as they are oppositely charged.
Covalent bonding occurs when atoms/molecules share pairs of electrons.
Metallic bonding is bonding that occurs in metals. This leads to giant structures of metal atoms arranged in a regular pattern. The outer shell electrons of metals are delocalised (free to move around) and so a metallic structure is a regular arrangment of +ve charged ions with negative electrons in between, held together by electrostatic forces of interaction.see more