Infection And Response Flashcards
Communicable disease
Caused by pathogens such as bacteria and viruses that can be passed from person to person
Bacteria
Single-celled living organisms
Split in two and produces toxins
Reproduce rapidly
Bacterial diseases - gonorrhoea
A sexually transmitted disease (STD) caused by a bacterium
Pain when urinating, yellow discharge
To prevent infection people can abstain from sex
Antibiotics against gonorrhoea
Bacterial diseases - salmonella
A bacteria that causes food poisoning
Often found in unhygienic kitchens, undercooked foods, or the same foods that have not been reheated properly
All poultry is vaccinated against it to stop the spread
Virus
Very, very small and have a regular shape
Take over the cells of your body to reproduce, causing damage and destroying cells
Reproduce rapidly
Viral diseases - tobacco mosaic virus
Transmitted by contact between plants, either naturally or through the hands of farmers
Effects the chloroplasts - changing colour from green to yellow/white
Reduces ability to photosynthesise and reduces crop yields
Viral diseases - HIV/AIDS
Transmitted by body fluids, often during unprotected sex, but also through cuts and injecting drugs using shared needles
After infection, people often suffer mild flu-like symptoms
AIDS is the last stage of HIV - attacks the immune system
Viral diseases - measles
Transmitted through the air in tiny droplets after an infected person sneezes
Children develop a fever and a rash
There are vaccines against measles
Protists
A eukaryotic, usually a single-celled, organism
Protist diseases - malaria
Spread by mosquitoes
Causes a fever and a rash
Spread of malaria is controlled by preventing the vectors, mosquitos, from breeding and by using mosquito nets to avoid being bitten
Fungi
A large group of eukaryotic organisms that contain single-celled yeasts, moulds and mushrooms
Fungal diseases - rose black spot
Transmitted in air or water, as well as through direct contact by gardeners
Infects leaves and causes black or purple spots on the leaves, the rest of the leaves often turn yellow and can drop off the plant
Treated using fungicides and removing infected plants
Natural barriers to pathogens
Chemical in tears
HCl acid in stomach
The skin on our body
Preventing spread of pathogens
Isolate those infected
Destroying vectors that carry the disease
Vaccinations
White blood cells
Ingest pathogens (phagocytosis)
Produce antibodies
Produce antitoxins
Vaccinations
A dead or altered form of the disease causing pathogen to be introduced into the body, which contains a specific antigen
This causes white blood cells to produce complementary white blood cells
Herd immunity
The protection given to a population against an outbreak of a specific disease when a very high percentage of the population has been vaccinated against it
Antibiotics
Substance that controls the spread of bacteria in the body by killing them or stopping them reproducing
Process of antibiotics
Antibiotics damage the bacterial cells but do not damage the host cells
They do not work on viral diseases as they reproduce inside host cells
Antibiotics - penicillin
The first antibiotic was discovered in 1928 by Alexander Fleming when he noticed some bacteria in a petri dish was killed by penicillium mould
Antibiotic resistance
The ability of bacteria to survive exposure to antibiotics, caused by mutations in their genes
Reasons for antibiotic resistance
Overuse of antibiotics
Failing to complete the fully prescribed course by a doctor
Painkillers
A chemical is taken to relieve pain associated with disease, but does not kill the pathogen
Traditional drugs
Were extracted from plants and microorganisms
E.g. penicillium, digitalis (heart drug originated from foxgloves), painkiller aspirin (originated from a willow tree)
