â30th and Main,â I replied. It was the home of one of Arielleâs book club friends, who Iâd overheard planning to âsurprise her.â Iâd never been there before, but with a little help of the internet I could easily figure out where her friend lived. Fox nodded and switched his car into gear.
bacteriophage. A bacteriophage is a type of virus that infects bacteria. In fact, the word bacteriophage literally means bacteria eater, because bacteriophages destroy their host cells.All bacteriophages are composed of a nucleic acid molecule that is surrounded by a protein structure.ventually, new bacteriophages assemble and burst out of the bacterium in a process called lysis. Bacteriophages occasionally remove a portion of their host cells' bacterial DNA during the infection process and then transfer this DNA into the genome of new host cells. This process is known as transduction.
The invading microbe or pathogen is called an antigen. It is regarded as a threat by the immune system and is capable of stimulating an immune response. Antigens are proteins that are found on the surface of the pathogen.Antigens are unique to that pathogen.The whooping cough bacterium, for example, will have different antigens on its surface from the TB bacterium. When an antigen enters the body, the immune system produces antibodies against it. type of white blood cell called a lymphocyte recognizes the antigen as being foreign and produces antibodies that are specific to that antigen. Each antibody has a unique binding site shape which locks onto the specific shape of the antigen.