The First line of Defence 7B Flashcards
Define Non-specific (U)
describes a component of the immune system that responds the same way to all pathogens
What is the Innate immune system (M)
a component of the immune system that is composed of generalised and non-specific defences and/or responses to pathogen
What is the first line defence
Physical
Barriers that prevent or impede entry of pathogens
Chemical
Barriers that inhibit the growth of bacteria and pathogens or destroy them
Microbiological
Non pathogenic bacteria in the body that prevent sthe colonisation or growth of pathogenic bacteria as they compete for both
What are chemical barriers for plants
Chemical barriers within plants are Antibacterial chemicals are produced by some plants they are called phytoalexins. They act as toxins to the invading organism by disrupting cell walls, delaying maturation, or interfering with metabolism.
Oxalix acids - a substance that can be toxic if ingested
What are phsyical barriers for plants
Waxy cuticles to avoid pathogenic bacteria growth of fungi infection when leaf is waterlogged
Bark
Physcial and Chemical barriers for humans
Physical
INTACT skin
Mucous secretion and hairs in the respiratory tract that trap organism and cilia that sweep pathogens out of the airways
Lysosyme enzyme in tears
Stomach acid
What are microbiological barriers
Gastrointestinal tract, on intact skin
Explain the effect of this chemical barrier on the structure and function of ATPase, and the ultimate consequence this has for Salmonella bacteria.
The low pH in the stomach environment is outside of the optimal pH range for salmonella ATPase.1Denaturation of ATPase occurs outside of its optimal pH, and the shape of the active site changes. ATPase can no longer bind to ATP, and the reaction releasing energy is no longer catalysed.2Consequently, there is insufficient energy for salmonella metabolic reactions, resulting in death of the bacteria.
Suggest how radioactive primers could be used to detect an adenovirus infection.
The use of radioactive primers complementary to viral DNA in the polymerase chain reaction can help detect the presence of a viral infection.1By annealing to the viral DNA, when the replicated DNA is viewed under UV light, the detection of the radioactive dye would indicate a viral infection.2
When infected with Neisseria meningitidis, a fever is often initiated. On a cellular level, explain how a fever can help combat bacterial meningitis.
Fevers, which increase core body temperature, can affect the functioning of bacterial enzymes through the elevation of temperature beyond their optimal temperature.1Therefore, the increased temperature may affect the 3D structure of those enzymes,2preventing their substrate from binding to the active site, helping limit infection by inhibiting reactions necessary for the survival of the pathogen from occurring.3
