Question

what are antibodies ? how do they fight bacteria and virus ?​

Answer 1

Answer:

An antibody is a protein produced by the body's immune system when it detects harmful substances, called antigens. Examples of antigens include microorganisms (bacteria, fungi, parasites, and viruses) and chemicals. ... Each type of antibody is unique and defends the body against one specific type of antigen.

Answer 2

Answer:

Antibodies are serum glycoproteins (protein covalently bonded to carbohydrates). These are $\gamma$ -shaped protein molecules composed of dour smaller polypeptides linked together.

When an antigen such as bacteria or viruses enters the blood, It binds to a special type of white blood cell called lymphocytes. Each Lymphocytes produces only one kind of antibody which binds to its surface. This attachment intern stimulates rapid division of the cell producing daughter cells.

These daughter cells are equipped to produce that antibody. Thus, in response to the entry of an antigen for injection, the level of the corresponding antibody rises in blood at an alarming high rate of about 2000 per second.