health, disease and the development of medicines

Health

A state of complete physical, mental, and social well being and not merely the abscence of disease or infirmity

Disease

A large of conditions that an cause ill health

Communicable disease

Passed from person to person

Non communicable diseases

Cannot be passed between individuals

Pathogens

Microorganisms that can cause disease

How do pathogens spread?

• Direct contact with contaminated surfaces

• Contaminated water

• Air

How to prevent pathogens from spreading?

• Improve hygiene eg wash hands

• Reduce contact with infected insivudual by quarantine

• Remove vectors with insecticides

• Vaccination

HIV

Virus that destroys white blood cells, lead to onset of aids AIDS. Spread by body fluids

Cholera

Bacteria causes diarrhoea. Spread by water

Tuberculosis

Bacteria causes lung damages and coughing. Spread by air

Chalara ash dieback

Fungi causes leaf loss, bark lesions, browning of leaves, malformations. Spread by air

Tobacco mosaic

Virus causes discolouration of leaves

Bacterial canker

Cause loss of leaves, stunt growth, formation of pus filled lesions on trunk

Aphids

Cause serious structural damage to plants

Malaria

Protists cause damage to blood and liver. Spread by animal vectors

Helicobacter

Bacteria leads to stomach ulcers. Spread by oral transmission

Ebola

Virus causes hemorrhagic fevers. Spread by bodily fluids

Lytic pathway

Virus uses host cell machinery to replicate its DNA. There are assembled to form new virus particles. One host cell is full of virus particles it will lyse. Repeated with nearby cells

Lysogenic pathway

Virus use restriction enzyme in insert it's DNA into the DNA of the host cell. The host cell replicates and viral DNA is also replicated. Starts lytic cycle.

Chlamydia

Bacteria causes painful urination or pelvic pain. Can lead to infertility

Physical barriers of plants

• Thick cellulose wall which is impermeable to apthogens

• Thick waxy cuticle

• Covered in dead cells sucks as bark

• Close stomota to stop pathogens in

Chemical barrriers of plants

• Produce antimicrobial chemicals, proteins and enzymes

• Release compounds that attract larger insects to feed on pests

Mechanical barriers of plants

• Thorns and hairs

• Leaves can curl and droop if insects and on them

Physical barriers of humans

• Skin- barrier against pathogens, protect tissue and cells

• Hair in nose

• Mucus produced by goblet cells to trap bacteria and pathogensin ariway

• Cilia- waft mucus to back of the throat to be swallowed to stomach

Chemical barriers of humans

• Lysozymes in white blood cells kill and digest bacteria

• Hydrochloric acid in stomach kills bacteria in food

Immune system response

• Phagocytosis

• Produce antibodies

• Produce antitoxins to neutralise toxins produced by pathogens

Vaccination

Making an individual immune to a disease as it contains dead pathogens which stmulte white blood cells to produce antibodies.

Herd immunity

Immunising a large population to reduce spread of pathogens as there's less people to catch it

Antibiotics

Used to treat bacterial infections by inhibiting cell process in bacteria but not host organism

Antigens

A structure that complementary antibodies bind to. Pathogens then clump together making pahgocytosis easier. Trigger production of memory lymphocytes. If infected with the same pathogen, antibodies will be produced at a faster rate