Disease Flashcards
Define a pathogen
Disease causing organism
What is a host?
Organism that is infected by a pathogen
What does the enzyme integrase do?
Catalyses reactions
What does protease do?
Breaks down large proteins
What does reverse transcriptase do?
Turns RNA into DNA by reverse transcription
How do viruses infected cells?
By integrating theor viral genome into host cells genome causing cells to make extra copies which bursts the cell
Why are new flu vaccines given each year?
Flu creates new variants which the vaccine would otherwise be ineffective to
What is TMV?
Virus which causes light green leaves and low crop
What is TB caused by?
Bacteria
How does TB effect cells?
Water droplets carrying disease release toxins from bacteria that damage the history cell
What is cholera caused by?
Bacteria
What is HIV caused by?
Virus
What is hypha?
Long branching structures of fungus containing one or more cells surrounded by tubular cell wall they also help make up mycelium
Hiw is cholera spread?
Through dirty water and poor sanitation
What is bacria cell walls made of?
Murein
What is black sigatoa caused by?
Fungal infection in plants
What plants are at risk of getting black sigatoa?
Bananas and plants in hot climates
What is ring rot caused by?
Bacteria
What is a sign of ring rot in a plant?
Ring of decay
What is potato blight caused by?
Protist
What is direct transmission?
Spread of a pathogen from 1 host to another
What is a droplet infection?
Droplets of a pathogen cause infection
What is athletes foot caused by?
Fungi
What is meningitis caused by?
Bacteria
Name some physical barriers, plant defenses
Waxy cuticle
Bark on trees
Cellulose cell wall
What is cellulose made of?
Beta glucose
Where are stem cells found in plants?
Meristems
How do plants respond to attacks from pathogens?
Actively and rapidly
Explain how callose is a physical barrier to plant pathogens
Callose is made of beta glucose and goes between the cell wall and cell membrane of infected cell. It contains lignin to strengthen its physical barrier.
Callose can also blocks sieve cells and plasmodesmata
Name some chemical defences plants have against pathogens
Antifungal
Insecticides
Outline how an antifungal works in control of the spread of a plant pathogen
Chitinase breaks down chitin in cell walls of fungi which weakens the disease
Outline the process from thromboplaston to thrombin
Thromboplastin turns to prothrombin and calcium ions convert that into thrombin
What is the effect of thrombin on fibrinogen?
Soluble fibrinogen turns to o soluble fibrin which attach to platelets to form a clot
Describe the inflammatory response caused by histamine
Histamine is released which increases the permeability of the capillaries allowing proteins and white blood cells to move out and into site of infection. An increase in tissue fluid causes swelling and the excess fluid is moved into the lymphatic system where lymphocytes attach to the antigen to trigger a specific immune response
Outline how mucus membranes protect against disease.
Mucus membranes trap pathogens. When the mucus is swallowed the extreme PH of hydrochloric acid causes the enzymes to denature and die
What type of epithelial tissue is the alveoli covered in?
Squamous epithelial
What happens to the lumen in blood vessels when infected by a pathogen?
Widen increasing blood flow
What are opsonins?
Proteins which attach to antigens enhancing an immune response
Outline phagocytosis
- Opsonin binds to antigen
- Neutrophil then binds and engulfs pathogen
- Phagosome then forms
- Lysosome fuse and release hydrolytic enzymes
- enzymes digest pathogen
What is APC and give an example?
Antigen presenting cell eg. Macrophage
Outline T lymphocyte responses
T lymphocytes mice from bone marrow to thymus where they differentiate
What happens when receptors on cytotoxic T killer cells are complementary to antigen?
Toxins are released resulting in apoptosis
What is clonal selection?
When the correct naive b cell is selected
What is clonal expansion?
Mitosis crates identical copies of b cells
What do b cells differentiate into?
B memory cells
B plasma cells
What is the variable region on an antibody?
Complementary to pathogen
What are the 2 regions on an antibody?
Variable and constant
What is agglutination?
When pathogens become clumped together on 2 binding sites
What is the structure of an antibody?
Soluble globular proteins with more than 1 amino acid chains
Define auto immunity
Immune response of an organism against its own healthy cells
Define an auto antibody
Antibody produced by immune system that is directed to the individuals own proteins
Name an example of an auto immune disease
Arthritis
Define active immunity
When naive b cells turn into memory cells and plasma cells to produce antibodies in body
Define natural active immunity
Antibodies are produced after you come into contact with pathogen in everyday life
Define artificial active immunity
Medical intervention produces antibodies eg. Vaccines
Define herd immunity
Large percentage of population is vaccinated
What type of immunity are vaccinations?
Active or passive
Define artificial passive immunity
Vaccines containing antibodies
Give an example of natural passive immunity
Mother passing on antibodies to baby via breast milk
What is penicillin and where was it found?
Antibiotics from mould
What is asprin and where is it found?
Painkiller from willow trees
Define pharmacogenetics
Personalised medication using human genomes
Define bactericidal
Kills bacteria
Define bacteriostatic
Slows growth and reproduction of bacteria
What is antibiotic resistance caused by?
Gene mutation