infection and response

Pathogens

Microorganisms that cause infectious disease

Communicable diseases

Can be spread between plants and between animals

4 types of pathogens

Bacteria, viruses, fungi , protists

Two things Bacterial pathogens may do

• reproduce quickly inside the body

• Produce toxins that damage tissue

Two things viral pathogens may do

• infect and reproduce inside body cells

• Cause damage to body cells

NON-SPECIFIC human defence systems against microbes

Nose, skin, stomach, trachea and bronchi

How does the nose defend against microbes

Hair and mucus trap microbes

How does the skin defend against microbes

It is a physical barrier

How does the stomach work as a defence system

Stomach acid which kills microbes

Does do the trachea and bronchi work against microbes

Cilia and mucus trap microbes and the cilia moves microbes back up

If pathogens do enter the body while blood cells are another defence, they go through a process called..

Phagocytosis

Phagocytosis

White blood cells engulf or inject pathogens and digest them

Another thing which white blood cells can do is produce anti bodies, how do antibodies work

anti bodies attach to antigens on microbes surface and kill pathogens

White blood cells can produce anti bodies and go through phagocytosis, what else can they do

Produce anti toxins

How do anti toxins work

They counteract toxins which destroy them

What are inside vaccines

Dead or weakened pathogen

How do vaccinations work

They are injected

White bloods cells are stimulated to produce anti bodies against pathogen

Memory cells stay

On reinfection anti bodies are produces very fast which kill all pathogens

Salmonella food poisoning is caused by which pathogen

Bacterium

How is salmonella spread

By eating infected food

Symptoms of salmonella

Fever, vomiting, abdominal cramps, diarrhoea

Ways to prevent salmonella

Vaccinating poultry, washing hands after toilet, disinfecting surfaces, washing hands when making food

gonorrhoea is a sexually transmitted disease caused by which pathogen?

Bacterium

How is gonorrhoea spread?

Sexual contact

Symptoms of gonorrhoea

Pain when urinating

Thick yellow or Green discharge from the vagina or penis

Ways to prevent gonorrhoea

Antibiotics and condoms

Measles is caused by which pathogen

Virus

How in measles spread

Inhaling droplets from sneeze or coughs

Symptoms of measles

Fever and skin rash

How can measles be prevented

Vaccinations in young children

HIV is caused by which pathogen

Virus

How is HIV spread

Sharing needles or sexual contact

HIV symptoms

Flu like illness

What can HIV progress onto

AIDS

AIDS

where the body can’t fight off infections

Treatment for HIV

condoms and antiretroviral drugs

Tobacco mosaic virus is what pathogen

Virus

how is TMV spread

Contact between plants

Treatment/ prevention of TMV

destroy or get rid of infected plants

TMV symptoms

Mosaic pattern of discolouration of leaves

Rose black spot is caused by which pathogen

Fungus

How is rose black spot spread

Wind or water

Symptoms of Rose black spot

Purple or black spots on leaves which turn yellow and drop

How to prevent rose black spot

Fungicides or destroy

Malaria is cause by which pathogen

Protist

How is malaria spread

Mosquitos which act as vectors (carriers)

Symptoms of malaria

Recurring fever which csn be fatal

How to prevent malaria

Stop the breeding of mosquitoes or using mosquito nets

Antibiotics

Cure BACTERIAL diseases by killing bacterial pathogens

Specific antibiotics kill

Specific bacterial pathogens

What is a great worry for scientists regarding antibiotics?

Bacteria can become resistant

Why can’t antibiotics kills viral pathogens?

Viruses reproduce inside body cells so it is difficult to develop drugs which kill viruses without damaging cells/tissue

Painkillers do not kill pathogens. they treat ..

Symptoms of illnesses eg headache

What plant does digitalis (heart drug) come from

Fox glove

Painkiller aspirin comes from which plant.

Willow

Penicillin come from

Penicillium mould

Who discovered penicillium mould

Alexander fleming

What testing and trialling new drugs what are they tested for

Toxicity, efficiency and dose

Pre clinical trials

Drugs tested on cells, tissues or animals in labs

If drugs after a pre clinical test are found to be safe what happens

They go to clinical trials

Clinical trials

Drugs on healthy volunteers to test for side affects

Double blind trials

One half of volunteers given real drug which other given a placebo

Why is peer review important when testing new drugs

To prevent false claims or bias

Monoclonal anti bodies are produces from

A single clone of cells

Monoclonal antibodies are specific to ?

One protein antigen

How are monoclonal antibodies produced

Using mice

When producing monoclonal anti bodies what are mice injected with

Protein antigen that we want antibodies for

Mouse lymphocytes produce

Antibody for antigen

What can lymphocytes do and cannot do

Do = make the antibody

Cannot do= divide indefinitely

What can you induce a mice to also make

A tumor cell

What can a tumor cell do and cannot do

Cannot = make anti body

Can = divide indefinitely

When you fuse a tumor cell and lymphocyte what is made

Hybridoma cell

When hybridoma cells clones they make many , what can these do

Can divide indefinitely so they csn make large quantities or the antibody

Uses of monoclonal antibodies

Pregnancy tests, laboratories , research for molecules in a cell/tissue, treatment of disease

How do pregnancy test works

-early pregnancy hormone is found in women

-detected in urine

-part of strip has fixed antibody which can detect hormone

-urine applied bottom of test

-urine soaks up test trip

-if hormone is present a colour chnage happens

To detect a pathogen or hormone with a monoclonal anti body , how do you know it’s there

Colour change

How can monoclonal antibodies identify molecules in cell or tissues

Monoclonal antibodies have fluorescent dye attached to them

They are then attached to cell

Fluorescence is shown under microscope is molecules are present

How do monoclonal antibodies work to treat cancer

They have a drug attached on the back

They attach to cancer cells

They destroy ONLY cancer cells

What are indicators of disease on a plant

Spots on leaves

Malformed stems or leaves

Discolouration of leaves

Stunted growth

Area of decay or rot

How to identify plant diseases

Refer to gardening website

Take plant to laboratory

Use testing kit which contains monoclonal anti bodies

Nitrate deficiency leads to stunted growth,why?

Nitrates are needed to make amino acids which make protein for growth

Magnesium deficiency leads to chlorosis , why

Magnesium ions needed to make chlorophyll, lack of chlorophyll means less photosynthesis which means less production of glucose

Plant physical defence responses

Layers of dead cells, waxy cuticles on leaf, cellulose cell walls

Chemical plan defences

Antibacterial chemicals

Thorns and hair

Leaves that droop when touched

Mimickry

Waxy cuticle of leaf

Tough layer to protect

Thorns and hairs

To deter animals