Immune system

• stomach

  Gastric fluid contains hydrochloric acid which kills bacteria's bacterial cannot survive in pH 1.0.
• Gut Flora

  Bacteria in small and large intestine which aid digestive processes

  Out-compete pathogenic bacteria because gut flora bacteria are more suited to the body's conditions
• Skin Flora

  -Communities of microorganisms that reside on the skin. protects pathogens invading by outcompeting

  secretes chemicals that kill / damage pathogens
• Skin

  → Keratin in Skin is a physical barrier to pathogens → pathogenic Bactria not suited to salty, acidic and chemical conditions of skin
• Path of entry

  If there is a cut, a blood clot forms. Triggers inflammatory response. Blood vessels release Histamines. Histamines cause arterioles to dialate, increasing blood to site of infection. Increase permeability of capillary allowing Odema to form. White blood cells attack microbes.
• Phagocytes

  White blood cells. Neutrophils. Macrophage
• Phagocytosis

  chemicals released by bacteria and damaged cells attract phagocytes → Neutrophils engulf bacteria before becoming inactive and dying = Macrophages destroy bacteria also by engulfing.

  Neutrophils produce highly reactive radicals nitric oxide and superoxide.
• Macrophage

  Apc = antigen presenting cell

  
• Interferon

  Interferon

  
• creating DNA fragments

  restriction endonucleases cut DNA at recognition sites which are specific base sequences complementary to the enzyme's active site

  different restriction endonucleases cut close to different STR sequences, resulting in fragments of different sizes
• role of primers

  primers are short sequences of single-strand DNA that have a specific base sequence

  anneal to complementary bases at either end of the DNA fragment to be amplified

  provide a site for taq polymerase to bind
• life cycle of blow flies affected by temperature

  (life cycle) depends on metabolic reactions

  (increase in temperature) increases the kinetic energy of enzymes

  Therefore there will be {more frequent collisions between enzyme and substrate
• conditions for bacterial growth

  warm, humid, optimal ph= enzyme activity

  oxygen-rich and glucose = for respiration

  amino acids = synthesis of DNA