1.Pathogens-Any living organism or virus that is capable of causing a disease. They include viruses, bacteria, protozoa, fungi, and worms of various types.
2.Antibiotics-Chemicals that take advantage of the differences between prokaryotic and eukariotic cells.
- many types: some selectively block protein synthase while others inhibit the production of new cells
- antibiotics damage or kill PROKARYOTIC cells, but not eukaryotic cells and their metabolism
e new viruses. Thus, they "hide" in our own cells using them as host cells, and that's why antibiotics don't work against viruses.
3. *Skin: Barrier to infection
- dermis:contains sweat glands, capillaries, sensory receptors, and dermal cells. They give structure and strength to skin.
- epidermis:(dead cells) not truly alive and they are intact= protected from most pathogens
- cells produce and secrete lining of mucus
- trap incoming pathogens
- some lined with CILIA-hair like extensions
- lysosyme-enzyme that damage pathogens
- Macrophages-large WBC that are able to change their cellular shape to surround an invader and take it in through the process of PHYGOCYTOSIS
- engulf pathogen- just like lysosomes in cell
- antigens-molecules that our immune system considers to be "not-safe"
- antibodies-protein molecules that we produce in response to specific types of pathogens
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjlXbDg3l9i40MsTmS5ZWQUT8WyOxAonZHVnnaDTp1uWsyJrxBlpJKGo42xzwOFitHZ_aVZFHH2Ra4d70_QycLtiU5D_hC8R-fM17VkgQH4FfOrV2M-COu9aCCX55o9jp6O2XT48XxthdwE/s320/0141.jpg)
- specific immune response
- pathogen enters body
- macrophage engulf pathogens
- pieces of pathogen become part of macrophage's membrane
- antigen presentation=lymphocytes T recognize pieces=are activated
- T cells activate specific B cells-they divide (by cloning) and form:
-memory cells-stay in circulation
7.Effects of HIV on immune system
- HIV (human immunodeficiency virus)-results in the set of symptoms called AIDS
- reverse transcriptase (enzyme) enables genetic info. of HIV to become integrated permanently into genome of host cell
- infects helper T cells- disables them=no antibody production=body doesn't fight pathogens as it used to before
- caused by HIV
- transmition: person to person by body fluids (blood transfusions/ sex/ etc)
- social implications: discrimination against infected people=labeled as homosexuals/drug abusers/ hard time finding jobs/ etc.
- its a virus=immune to vaccine (hides away in host cells)