Immunity

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Pathogens cause disease by damaging cells of the host and by producing toxins.

Phagocytes destroy and prevent the spread of micro-organisms that enter the blood and other tissues.

Antigens are proteins on the outer surface of the cell that trigger an immune response.

Antibodies are protein molecules that can bind specifically to an antigen.

Made by B-cells (a WBC)

Each antibody is formed in response to an antigen

The secondary response is usually:

Steeper

Faster

Bigger

Monoclonal antibodies are formed from a single WBC.

Uses of monoclonal antibodies include:

Pure forms of antibody (injection against infection)

Pregnancy tests

HIV tests

To treat cancer cells

Wash well:

To remove antibodies that do not bind so enzyme does not cause a colour change.

No colour change if _____ antibodies are not present, why?

The 2nd antibody will not attach if the _____ antibody is not present. The enzyme is not present either so the colour does not change as both the 2nd antibody and enzyme are washed away.

Antibodies used must be monoclonal because...

Only complimentary to the _____ antigen.

Passive immunity:

Ready-made antibodies

Have not made own antibodies

Short lived

Antibodies will be destroyed by WBCs

Active immunity:

own antibodies.

Key words

Common QS Answers