Infection and Response Flashcards
What are pathogens
Microorganisms that enter the body and cause disease
How do bacteria make you feel ill
Secreting toxins
How do viruses make you feel ill
Reproduce inside of your cells
Mass copy themselves
Burst the cell releasing the copies
How do protists make you feel ill
Transmitted through vectors into/ onto your cells
How do fungi make you feel ill
Spores which are absorbed by the body
Examples of ways pathogens can spread
Water
Air
Direct Contact
What is measles
A virus
Spread by droplets from a person’s sneeze/cough
It can be very serious, causing rashes and sometimes inflammation of the brain
Most people are vaccinated against it as a child
What is HIV
A virus
Spread by sexual contact or sharing of blood. It causes flu-like symptoms for a few weeks and during this time it can be controlled with drugs
The virus attacks the immune cells
It lowers the body’s ability to cope with other pathogens
What is tobacco mosaic virus (TMV)
A virus that affects plants
It causes a mosaic pattern on the plant that discolours parts of the leaves
Therefore the plant’s ability to carry out photosynthesis is affected, stunting growth
What is rose black spot
A fungus
Causes purple/black spots to develop on the leaves of rose plants
The leaves can then turn yellow and then drop off
Less photosynthesis can happen then
It spreads through wind/water
Treated using fungicides or stripping affected leaves
What is malaria
A protist transported by a mosquito
It can cause repeating episodes of fever and the spread can be stopped by stopping mosquitos from breeding
What is salmonella
bacteria that causes food poisoning
the infected can suffer from fever, stomach cramps, vomiting and diarrhoea
you get it by eating food contaminated with the bacteria
in the UK most poultry is vaccinated
what is gonorrhoea
a STI caused by bacteria
caused by sexual contact
originally treated with an antibiotic by trickier now due to resistance
treated using antibiotics and barrier methods of contraception
how can the spread of disease be reduced/prevented
being hygienic
destroying vectors
isolating infected individuals
vaccination
Examples of your body’s defence system (not white blood cells)
skin as a barrier to pathogens
hair and mucus in nose trap particles that could contain pathogens
cilia which trap and waft mucus to the back of your throat
stomach produces HCl which can kill pathogens
What can phagocytes do
engulf and destroy pathogens - called phagocytosis
What can lymphocytes do
Produce antibodies that are specific to the antigen
Produce anti-toxins to the bacteria
How do vaccines work
Inject with a dead or inactive pathogen so that the body produces the antibodies that are specific to that virus and then if the body is infected again it will respond quicker
pros and cons of vaccines
pros:
help to control some diseases
herd immunity
cons:
don’t always work
side affects
what are painkillers and how are they different to antibiotics
drugs that reduce the symptoms
this is different to antibiotics which kill the bacteria
antibiotics don’t work on viruses!
how can bacteria mutate to become resistant
the non-resistant bacteria die and the resistant ones continue to live and multiply
eventually all the bacteria will be resistant
How to slow down the rate of development of resistant bacteria
not over-prescribe bacteria
finish course
what is aspirin and where did it originally come from
painkiller and found in willow
where did digitalis come from and what is it
used to treat heart conditions and found in foxgloves
how was penicillin discovered and by whom
alexander fleming
one of his petri dishes containing bacteria and had mould on it but a section of it did not
the mould was secreting a chemical (penicillin) that was killing the bacteria
stages of testing drugs
Preclinical drug trials - Tested on cells in labs and on computer programs - used to test side effects
Animal trials - Tested on animals and monitoring them - can be used to figure out dose and side effects
Human clinical trials - tested on healthy volunteers to see side effects
Then tested on those suffering from the illness
Then placebo and double blind trials
Then peer review
What are monoclonal antibodies produced from
Lots of clones of a single white blood cell
How to produce monoclonal antibodies
Mouse injected with an antigen
Lymphocytes which can produce specific antibodies taken
Fused with a tumour cell to form a hybridoma which can produce the antibodies and divide rapidly
Cloned
Purified and stored
How are monoclonal antibodies used in pregnancy test
HCG binds to the antibodies
HCG is only found in the urine of pregnant women
It will ‘stick’ to the test strip
How can monoclonal antibodies be used to treat cancer
the antibodies, which are attached with an anti-cancer drug, can bind to the antigens on a tumour’s surface
it will kill just the tumour
How can monoclonal antibodies be used to test for substances
Bind to hormones and other chemicals in blood to measure their levels
Test for pathogens
Locate specific molecules on a cell/tissue
Use a fluorescent dye bound to the MA first
Disadvantages of monoclonal antibodies
They can affect normal body cells when used to treat diseases
Can cause more side effects than initially expected
Expensive to develop
What does nitrate deficiency look like in plants
Stunted growth as nitrates are needed to make proteins
What does magnesium deficiency look like in plants
Yellow leaves as the plant is likely suffering from chlorosis as magnesium is needed for making chlorophyll
What are the common signs a plant has a disease
Stunted growth
Abnormal growths
Spots on leaves
Malformed stems/leaves
Discolouration
Examples of physical plant defences
Waxy cutices
Layers of dead cells (bark)
Cell walls
They form a physical barrier against pathogens
Example of chemical plant defences
Antibacterial chemicals
Poisons
Secrete things to fight the pathogen
Example of mechanical plant defences
Thorns and hairs
Drooping or curling
Mimicking
Putting predators off touching them
