Unit 3- infection and response Flashcards
What are pathogens
Microorganisms that enter body and cause disease
What are the different types of pathogens
Bacteria, viruses, protists, fungi
What is bacteria infection
Small cells that produce toxins that damage your cells and tissues, can be killed using antibiotics
What are viruses
Not cells, they only reproduce in a host cell, when virus leaves the cell it can cause the cell to burst and die, cannot be killed by antibiotics
What are protists and parasites
Single celled eukaryotes.
Parasites live on or inside other organisms and can cause damage. They are often transferred by a vector (insect that carries the protist)
Ways pathogens can spread
Water, air , direct contact
What is fungi infections
Some are Single celled
Others have a body which is made up of hyphae this will grow and cause diseases
Examples of virus infections
Measles, HIV, tobacco mosaic viruses
Example of fungal disease
Rose black spot
What is measles
Spread by droplets from peoples cough or sneeze
Will develop a red rash and a fever
Can be fatal
What is HIV
Sexually transmitted disease
What is tobacco mosaic virus
Affects plant species
Causes a mosaic pattern on leaves of plant cause discolouration
Means photosynthesis is reduced therefore growth is also reduced
What is Rose black spot
Causes purple or black spots on leaves of rose plants
Means less photosynthesis
Spreads through wind and water
Treated by using fungicides and or removing and destroying the affected leaves
Example of protist disease
Malaria
What is malaria and what is the vector
Vector - mosquitos
Mosquito inserts parasite and infects the body
Can be fatal
Example of bacteria diseases
Salmonella, gonorrhoea
What is salmonella
food poisoning
Can suffer from vomiting diarrhoea and fever
Caused by toxins
What is gonorrhoea
Sexually transmissible disease
Treated with antibiotic like penicillin
Symptoms include discharge and pain when urinating
What happens when a pathogens enters the body
1)White blood cell will engulf foreign cells and digest them
2)white blood cells will then produce antibodies to lock onto invading cells ans destroy them
3)produce antitoxins
How does vaccination work
-inject a small amount of dead or inactive pathogens
-causes white blood cells to produce antibodies to attack them
-so if the pathogen ever appears again the white blood cells can rapidly produce antibodies to kill off the pathogens
Pros and cons of vaccinations
Pros :
-helped control communicable diseases
-big outbreaks of diseases can be prevented if large percentage of population is vaccinated
Cons:
-don’t always work (don’t give your immunity )
-sometimes have a bad reaction to them (fever or seizures)
What do antibiotics do
Kill or prevent growth of the bacteria without killing your own body cells.
However they don’t destroy viruses (flu)
What are the stages of drug testing
-Drugs are tested on human cells and tissues
-test drug on live animals
-then tested on human volunteers in clinical trial
How does your nose and mucus help fight disease
Traps particles that could contain pathogens
What does the trachea and bronchi do to help prevent diseases
Produces mucus
What does the stomach do to prevent diseases
Produces hydrochloric acid that kills pathogens that enter stomach
What are monoclonal antibodies
Proteins that target specific cells
What animal is used for monoclonal antibodies
Mouse
What are antibodies produced by
White blood cells called Lymphocytes
Steps of monoclonal antibody
- Mouse injected with antigen
- Collect lymphocytes from mouse that make a specific antibodies to antigen
- Lymphocytes are fused with tumour cell
- This will create a hybridoma
- Hybridoma cloned to create many cells that produce antibodies
Explain how pregnancy tests work
- HCG is hormone found in urine of pregnant people
- Urine travels up stuck and over HCG specific monoclonal antibodies
- If HCG is present in urine it will bind to the antibodies and a colour change will occur indicating they are pregnant
2 ways monoclonal antibodies can be used in diagnosis or treatment of cancer
- Locates cancer cells so they can be treated and removed
- Can block chemicals that cause the cancer to divide
Disadvantages of monoclonal antibodies
Expensive, side effects
What is a hybridoma
Cells created during monoclonal antibodies by the fusion of antibodies (specific lymphocytes and tumour cells)
What plant was used as a pain killer
Willow Bark
How does bacteria pathogens make us ill
Once inside human body they reproduce rapidly
They release harmful chemicals called toxins
What do toxins do
Damage tissues and make us feel ill
How to reduce spread of pathogens
-wash you hands before eating
-clean drinking water
-use a condom during sexual contact
-vaccination
What is HIV and symptoms
-flu like illness
-immune system becomes damaged so more likely to catch other infections
-spread by sexual contact or exchange of bodily fluids such as blood which occurs when drug users share needles
-patient
How is salmonella controlled in the UK
All chickens are vaccinated against salmonella which controls the spread
Symptoms of malaria
Fever
What is a vector
Something that carries the pathogen from one person to another
Ways to stop spread of malaria
Stop mosquitoes breeding in still water so drain ponds
Sleep under mosquito net
How does the skin prevent pathogens
-outer layer is made up of dead cells so difficult for pathogens to penetrate
-produces oily substance called sebum which kills bacteria
How does the nose prevent pathogens entering body
Contain hair and mucus, these trap pathogens before entering breathing system
Role of immune system
Destroys pathogens and any toxins produced
Protects us in case same type of pathogen invades us in the future
What is the process of phagocytosis
White blood cells detect chemicals produced by pathogen and moves towards it
Then ingests pathogens
Enzymes in the phagocyte break down the pathogen and destroy it
What are antibodies
Protein molecules produced by white blood cell
Role of antibodies
Antibodies stick to pathogens which triggers pathogen to be destroyed
Can produce antitoxins which stick to toxin molecules and prevent them from damaging the cell
What is a placebo
A tablet or injection with no active drug in it
Uses of monoclonal antibodies
-can be used to detect a specific hormone like in pregnancy testing
-measure levels of hormones in blood
- detect pathogens in the blood
-locate specific cells or tissues
What does a lack of nitrate ion cause in plants
Stunted growth
Why does a lack of nitrate ion cause stunted growth
Nitrate is needed for protein synthesis and therefore growth
What does a lack of a magnesium ion cause in plants and why
Causes the condition chlorosis (leaves loose there green colour) because magnesium is required to make chlorophyll
Why are some patients given a placebo
To compare effect of treatment versus no treatment
What are the 2 types of tumours
Benign and malignant
What are benign tumours
Growths of abnormal cells which are found in one area, usually contained within a membrane
Main characteristic of a benign tumour
Do not invade other parts of the body they stay in one place
Main characteristic of a malignant tumour
Malignant cells invade neighbouring tissues and move into bloodstream, they spread to different parts of the body and form new tumours, they are classed as a cancer
What is a secondary tumour
When the malignant cells spread to new parts of the body they form secondary tumours
Why do we do clinical tests before they can be used by public
-to check for side effects
-to check dosage
-to check it is safe
How does salmonella cause vomiting and diarrhoea
Release toxins
How do trachea and bronchi prevent infection
-trachea have hairs called cilia
-these waft their and hairs and move mucus and pathogen upwards towards the throat where it is swallowed into stomach
Uses of monoclonal antibodies
-For diagnosis such as in pregnancy tests.
-In laboratories to measure the levels of hormones and other chemicals in blood, or to detect pathogens.
-In research to locate or identify specific molecules in a cell or tissue by binding to them with a fluorescent dye.
-To treat some diseases: for cancer the monoclonal antibody can be bound to a radioactive substance, a toxic drug or a chemical which stops cells growing and dividing. It delivers the substance to the cancer cells without harming other cells in the body.
How to detect plant disease
-stunted growth
-spots of leaves
-areas of decay
-growths
-malformed stems of leaves
-discolouration
-presence of pests
How can plant disease identification be made
-reference to a gardening manual or website
-taking infected omanis to a laboratory to identify the pathogen
-using testing kits that contain monoclonal antibodies
What is a double blind trial
neither the participants nor the researchers are aware which group has been given the drug and which group has been given the placebo
