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Immune System Benchmark Study Guide. What is a PATHOGEN ?. Anything that causes disease Can be a bacteria, virus, fungi, parasites Bacteria produce toxins Viruses lyse cells. What is a VIRUS?. A non-living particle that requires a host to replicate Can cause disease
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What is a PATHOGEN? • Anything that causes disease • Can be a bacteria, virus, fungi, parasites • Bacteria produce toxins • Viruses lyse cells
What is a VIRUS? • A non-living particle that requires a host to replicate • Can cause disease • Found in soil, water, air, surfaces
What happens during the LYTIC CYCLE? • Attachment • Entry • DNA Replication and Virus Protein Production • Assembly • Lysis
What happens during the LYSOGENIC CYCLE? • Attachment • Entry • Provirus – Viral DNA is incorporated into host DNA • Cell DNA with virus DNA is replicated
What adaptations allow bacteria to survive in different environments? • Cell Walls • Can withstand harsh environments • Endospores • Aerobic or anaerobic respiration
What are some useful uses for bacteria? • Make cheese and yogurt • Clean spills • Make antibiotics • Nitrogen fixation • Recycle nutrients/decomposers
Describe how Robert Koch explained the cause of disease. Steps? • Pathogen is isolated from a host • Pathogen is grown/cultured • Pathogen is introduced to another host • New host becomes ill, must have same symptoms • Pathogen is isolated – must be same pathogen as original
What are the causes of… • Malaria – plasmodium parasite on mosquitoes • Mosquito is a vector • HIV – Virus • Passed through exchange of body fluids • Shingles – Virus • Passed on by contact/droplets
Define INNATE IMMUNITY • First line of defense • Barriers and Mucus • Non-specific defense • Skin • Mucus membranes • Tears and Saliva • Lysozyme enzyme – breaks down bacterial cell walls and membranes
What is INFLAMMATION? • Non-specific defense • 2nd Line of Defense • Entry of pathogen • Mast cells release histamine • Histamine triggers – pain, heat, swelling, redness • Dilate red blood vessels to allow phagocytes to damage site • Phagocytes (macrophages, monocytes, neutrophils) digest pathogens • Pus
How does the body react to viral infections? • Virus infected cells release INTERFERONS • Interferons (chemicals) tell neighboring cells to make antiviral proteins • Viruses cannot enter neighboring cells
What is the function of white blood cells? • Basophils – make histamine • Macrophage – digest invading cells
Describe 2 ways bacteria can reproduce? • Binary fission • Asexual reproduction • One bacteria replicates DNA and divides into two cells • Conjugation • Sexual reproduction • One bacteria passes on a plasmid or new DNA to another bacteria through pili
What is ACQUIRED IMMUNITY? • 3rd Line of Defense • Build up resistance • Specific Immunity • Body uses T and B cells against a specific pathogen • Cellular Immunity • Antibody Immunity
Cellular Immunity • Pathogen is engulfed by macrophage • Macrophage presents digested pathogen to Helper T Cell • Helper T cell activates Cytotoxic T cells • Cytotoxic T cells signal infected cells to commit “suicide” • Memory Cytotoxic T cells are made
Antibody Immunity • Pathogen (bacteria) is engulfed by macrophage • Macrophage presents digested bacteria to Helper T cell • Helper T cell activates B cell • B cell turns into plasma cell • Plasma cell makes Antibodies • Antibodies circulate through blood stream to find and collect bacteria
What is PASSIVE IMMUNITY? • Receive Antibodies by injection or breast feeding • Passive – you DON’T make antibodies yourself • Temporary
What is ACTIVE IMMUNITY • Occurs Naturally – You build up immune system • You have to get sick • Body makes memory B and T cells
What is an ANTIBIOTIC? • Most come from penicillin • Target – bacterial infections • CANNOT be used on viruses • Break down the cell walls
What is RESISTANCE? • When a bacteria is no longer sensitive to antibiotics