Infection and Responce Flashcards
What are the 4 types of pathogen?
- bacteria
- viruses
- protists
- Fungi
What are pathogens?
microorganism’s that enter the body and cause disease
What is a communicable disease?
infectious disease that can spread easily
What can be infected by pathogens?
plants and animals
What are bacteria?
very small living cells which can reproduce rapidly inside your body
they can make you feel ill by producing toxins that damage cells and tissues
What are virsuses?
- they are not cells
- extremely tiny
- reproduce rapidly inside body
- live inside cells and replicate them using cells machinery to produce more copies of themselves
- cell then bursts releasing virus
- cell damage makes you feel ill
What are protists?
- single celled eukaryotes
- some are parasites which live on or inside other organisms and causes them damage
- often transferred to organism by a vector which doesn’t have the disease
What are fungi?
- some are single celled
- some have a body made up of hyphae
- hyphae can grow and penetrate skin, surface of plants which causes disease
- hyphae produce spores which can be spread to other animals or plants
What are the ways pathogens can be spread?
- water
- air
- direct contact
What is measles?
a viral disease spread by droplets of an infected persons sneeze or cough
What do people with measles develop?
red skin rash and show signs of a fever
What are some of the consequences of measles?
- can be fatal
- can lead to lung infection or brain infection
vaccinated when young
What is HIV?
a virus spread by sexual contact, or exchanging bodily fluids such as blood. the virus attacks the immune cells
What happens if you get HIV?
causes flu like symptoms. Usually no symptoms for years.
What can HIV be treated with?
antiretroviral drugs to stop virus replicating in body
What does TMV stand for?
tobacco mosaic virus
What is TMV?
a virus that effects species of plants
What does TMV cause?
a mosaic pattern on leaves of plants, some parts become discoloured
What does TMV mean for the plant?
can’t photosynthesise as well
Give an example of a fungus disease?
rose black spot
What does rose black spot cause?
purple or black spots to develop on the leaves of rose plants, the leaves can grow yellow and drop off, means photosynthesis can’t happen as plant doesn’t grow very well
How does rose black spot spread?
through the environment in water or wind
How can rose black spot be treated?
using fungicides and stripping the plant of its effected leaves
What is a Malaria caused by?
a protist
What are mosquitoes?
vectors - they pick up the malarial protist when they feed on an infected animals
How do mosquitoes infect someone?
inserting the protist into the organisms blood vessels
What does Malaria cause?
repeating episodes of fever, can be fatal
What is salmonella?
type of bacteria that causes food poisoning
What can infected people experience with salmonella?
fever, stomach cramps, vomiting, diarrhoea
What are salmonella symptoms caused by?
toxins that are produced by bacteria
What can you get salmonella from?
food that is contaminated
What is gonorrhoea?
a sexually transmitted disease
how is gonorrhoea passed on?
sexual contact
what is gonorrhoea caused by?
bacteria
symptoms of gonorrhoea?
pain when urinate, thick green discharge
what 4 things can you do to prevent the spread of disease?
- being hygienic
- destroying vectors
- isolating infected vectors
- vaccination
Describe some of the bodies defence systems?
- skin, barrier to pathogens and secretes antimicrobial substances which kill pathogens
- hair and yucas in your nose, trap particles that contain pathogens
- trachea and bronchi, secrete mucus to trap pathogens and lined with cilia which waft mucus up the back of throat where it can be swallowed
- stomach produces hydrochloric acid , kills pathogens
What do white blood cells do?
travel around in blood and crawl into every part of you, patrolling for microbes
when they come across an invading microbe they have three lines of attack
Explain the first line of attack for white blood cells?
engulf foreign cells and digest them - phagocytosis
Explain the second line of attack for white blood cells?
- every invading pathogen has unique molecules ( antigens) on surface
- when come across a foreign antigen, produces protein called antibodies which lock onto invading cells so can be found and destroyed by white blood cells
- antibodies produced are specific to type of antigen
- antibodies produced rapidly and carried round body to kill the whole bacteria or virus
- now the person is naturally immune
Explain the third line of attack for white blood cells?
- produce antitoxins which counteract toxins produced by invading bacteria
What does a vaccination do?
protects you from future infections
What doe vaccinations involve?
injecting small amounts of dead or inactive pathogens which carry antigens, this causes your body to produce antibodies and attack antigens
What are the pros of a vaccination?
- can help control lots of communicable diseases that were once common in the UK
- big outbreaks of disease can be prevented if mass vaccination take place
What are the cons of a vaccination?
- don’t always work, some can be immune
- you can sometimes have a bad reaction
what do painkillers do?
- relieves pain - don’t actually tackle the cause of the disease or kill pathogens - just reduce symptoms
What do antibodies ( penicillin) do?
- kill bacteria that is causing the problem
what do different antibiotics do?
kill different types of bacteria
What do antibiotics not do?
destroy viruses
Why are viruses hard to treat?
they reproduce using body cells, hard to attack without harming body cells
What can bacteria be?
mutate - resistant to antibiotics due to mutations
What can happen if bacteria are mutate?
only some are killed and the rest can survive and reproduce
How can doctors slow down the rate of developing resistant strains?
avoid over prescribing antibiotics
What are a lot of drugs from?
plants
describe aspirin?
- from a chemical found in willow
- painkiller to lower fever
What is digitalis?
treats heart conditions
- developed from foxgloves
Who discovered penicillin?
Alexander Fleming
How are large scale drugs made?
in the pharmaceutical industry
explain the first stage in drug testing?
- preclinical testing in human cells and tissues in lab
- can’t use to test the affects on whole or multiple organs
Explain the second stage of drug testing?
- on live animals to test efficacy, toxicity and to find best dosage
- tested on two different live mammals
Explain the third stage of drug testing?
- tested on human volunteers in a clinical trial
1. tested on healthy volunteer - see if any harmful side effects, low dosage
2. suffering from illness , optimum dose found
3. two groups, one given drug one given placebo - to see actual difference drug makes, sometimes doctor and patrons don’t know if got drug or placebo- no subconscious influence
4. peer review
What is a placebo?
a substance like the drug being tested but doesn’t do anything
What are monoclonal antibodies?
identical antibodies produced by B-lymphocytes
What are B-lymphocytes?
type of white blood cell
What are monoclonal antibodies produced from?
lots of clones of a single white blood cell. all antibodies are identical and will only target one specific protein antigen
What is the problem with lymphocytes?
don’t divide easily
What is a benefit of tumour cells?
divide lots so can be grown easily
How do you create a hybridoma?
a mouse B-lymphocyte with a tumour cell
What can hybridoma cells do?
cloned to get lots of identical cells which produce antibodies that can be collected and purified
Why are monoclonal antibodies useful?
they will only bind to target molecule - can use them to target a specific cell or chemical in the body
when are monoclonal antibodies used?
pregnancy tests
What hormones are found in pregnant women urine?
HCG
Explain how pregnancy tests work?
- stick you pee on has same antibodies to the hormone, with blue heads attached
- test strip ( bit that turns blue if pregnant) has antibodies to the hormone stuck on it
- if pregnant the hormone binds to antibodies on blue beads
- urine moves us stick, carrying hormone and blue beads
- beads and hormone bind to antibodies on strip
- blue beads get stuck to strip turning it blue
- If not pregnant urine still moves up stick but nothing sticks to blue bleeds so colour does not show
What do plants need?
mineral ions
Why are nitrates needed in plants?
needed to make proteins and therefore for growth
- If not enough causes stunted growth
Why are magnesium ions needed for plants?
making chlorophyll, which is needed for photosynthesis.
without enough magnesium suffer from chlorosis and have yellow leaves
What can plants be infected by?
viral, bacterial and fungal pathogens, infeste and damaged by insects
What are the common signs of disease in plants?
- stunted growth
- abnormal growths
- spots on the leaves
- patches of decay
- malformed stems or leaves
- discolouration
how do you identify plant diseases?
- gardening manual
- gardening website
- taking infected plant to laboratory
- using testing kits that identify the pathogen using monoclonal antibodies
what are the physical defences of a plant?
- waxy cuticle, barrier to stop pathogens from entering
- cell walls
- layer of dead cells around stems
what are the chemical defences of a plant?
- some produce antibacterial chemicals which kill bacteria
- some produce poisons which can deter herbiovors
what are the mechanical defences of a plant?
- some adapted to have thorns and hairs - stop animals from toughing and eating them
- dropped or curled leaves when something touches them- prevent from being eaten by knocking insects off
- can mimic other organisms, eg bright spots that mimic a butterfly eggs to stop other butterflies laying eggs there
what do different cells in the body have?
different antigens on the cell surface, so can make monoclonal antibodies that will bind to specific cells in the body
what do cancer cells have?
antigens on cell membrane that Arnt found on normal body cells - tumour markers
what can an anti-cancer drug do?
attach to tumour monoclonal antibodies
What are some monoclonal antibodies that anti cancer drugs can attach to?
radio active substance, toxic drug or chemical which stops cancer cells growing and dividing
Explain hoe monoclonal antibodies can treat disease?
- given to patient through drip
- antibodies target specific cells because only bind to tumour markers
- drug kills cancer cells but doesn’t kill any normal body cells near the tumour
how monoclonal antibodies can be used in laboratories to find specific substances?
- bind to hormones and other chemicals in blood to measure their levels
- test blood samples in laboratories for certain pathogens
- locate specific molecules on a cell or in a tissue
How can monoclonal antibodies be used to locate specific molecules on a cell or in a tissue?
- first made to bind to the specific molecules you’re looking for
- antibodies bound to a fluorescent dye
- if molecules are present, monoclonal antibodies will attach to them and can be detected using dye
What are the advantages of monoclonal antibodies?
- cancer treatment as it doesn’t affect normal body cells
- lower side effects then other cancer treatments
What are the disadvantages of monoclonal antibodies?
- can cause fever, vomiting, low blood pressure
