IB Bio

• microbe


  microscopic life form; microorganism; germ

  
• Bacteria


  (microbiology) single-celled or noncellular spherical or spiral or rod-shaped organisms lacking chlorophyll that reproduce by fission

  
• Fungi


  A kingdom made up of nongreen, eukaryotic organisms that have no means of movement, reproduce by using spores, and get food by breaking down substances in their surroundings and absorbing the nutrients

  
• E. coli

  type of bacteria

  
• Agar

  a gel-like polysaccharide compound used for culturing microbes; extracted from certain red algae

  
• skin


  largest organ of the body- used to defend the body against invaders

  
• Phagocytes


  A type of white blood cell that ingests invading microbes

  
• pus


  A fluid created by infection.
• scab

  crust that forms over a wound or sore during healing- stops bacteria from entering

  
• stomach acid (HCl)

  toxic to organisms- helps to kill off microbes entering the body- found in the stomach

  
• tears


  wash organisms away

  
• eyelashes


  the cilia or hair that prevent foreign structures from irritating the outer eye

  
• cilia in trachea


  small hairs that sweep mucus to the back of the throat where it is then swallowed

  
• nasal hairs


  filter and trap microorganisms in nasal passages

  
• immune system


  The cells and tissues that recognize and attack foreign substances in the body

  
• Pathogen


  a bacterium, virus, or other microorganism that can cause disease.

  
• Virus


  A tiny, nonliving particle that invades and then reproduces inside a living cell- causing illness

  
• Protozoa


  microscopic, one-celled animals often found in decayed materials and contaminated water

  
• fever


  elevated body temperature that occurs in response to infection

  
• vaccination


  injection of a weakened or mild form of a pathogen to produce immunity

  
• Symptoms


  Subjective characteristics of disease felt only by the patient

  
• lymphocytes


  lymphocytes are a type of white blood cell found both in the lymph nodes and circulating in the blood; t cells & b cells
• antigens 


  Molecules that trigger an immune response in this way are named antigens. Antigens are found on cell surface membranes of cancer cells, bacterial cell walls, the envelopes of viruses and even pollen grains. 
• herd immunity 


  when enough of the population has immunity towards a certain pathogen that it eventually disappears
• antibodies 


  chemicals that kill bacteria, it blocks prokaryotic features but not eukaryotic animal ones 
• blood clotting


  Blood clots at the site of a wound -> prevent blood loss and entry of pathogens
• clot initiation

  Platelets (thrombocytes) release clotting factors in response to a wound by grouping themselves together (agragation)
• clot formation

  1. Clotting/coagulation factors cause cascade of reactions (thrombin converts fibrinogen -> fibrin, fibrin -> fibrin polymers, retraction) 
  2. Formation of insoluble protein mesh made of fibrin 
  3. Fibrin cells capture blood cells 
  4. Formation of scab due to oxidation
• fibrinolysis

  enzymatic breakdown of the fibrin in blood clots
• Thrombosis


  blood clot in artery which causes a blockage in blood flow
• Macrophage

  Type of WBC that is involved in the early process of fighting off pathogen

  -> Large webs can change their cellular shape to surround the pathogen and take it through the process of phagocytosis
• Diapedesis

  the process that allows the macrophage to pass through the capillaries to engulf , then the enzymes will digest the pathogens
• Pus formation

  the waste excretion from the digestion of pathogen by macrophage, found in open wounds 
• Cell-to-cell recognition

  protein molecules on the cell surface membrane  to help determine whether a cell is ‘self’ or ‘non-self’. This includes receptors such as; antigens and antibodies
• Haematopoiesis

  process of stem cell differentiation of blood cells
• T Cells

  a lymphocyte that can directly attack a pathogen when activated
• B Cells

  a lymphocyte that produces antibodies
• glycoprotein

  polysaccharide and protein molecules, found on plasma membrane, helps make up antigens
• Antibodies

  receptor proteins to identify and neutralize antigens, they are composed of two main parts;

  • body
  • binding site
• Outline how macrophage is able to aid in nonspecific defense?

  1. recognizes the pathogens via the protein receptors
  2. once it determines that it is a non-self cell, it extends the plasma membrane and engulfs the pathogen by phagocytosis
  3. the enzymes will degrade and break down by lysis
  4. the antigens left behind will be present on the macrophage's membrane in order to be recognized by the helper t-cells that releases cytokines
  5. this release will cause a cascade of immune responses by an influx of macrophage onto the recognized area