Health, Disease And Development Of Medicines Flashcards
How do viruses cause damage?
- Move into cells and make many copies
- This leads to cell bursting, causing the person to feel ill
How do bacteria cause damage?
They produce toxins that damage cells
What are the four types of pathogen?
- Bacteria
- Virus
- Fungi
- Protist
What are the main effects of cholera? Type of pathogen?
- Bacteria
- Diarrhoea
What are the main effects of malaria? Type of pathogen?
- Protist
- Causes damage to blood and liver
What are the main effects of HIV? Type of pathogen?
- Virus
- Destroys white blood cells, leading to the onset of AIDS
What are the main effects of tuberculosis? Type of pathogen?
- Bacteria
- Causes lung damage, coughing
What are the main effects of Ebola? Type of pathogen?
- Virus
- Causes haemorrhagic fever (fever with severe bleeding)
What are the main effects of helicobacter? Type of pathogen?
- Bacteria
- Can lead to stomach ulcers
What are the main effects of Chalera ash dieback? Type of pathogen?
- Fungi
- Leaf loss and bark lesions
How is cholera spread? How can the spread be reduced?
Spread - by water
Can be reduced by - boiling water before drinking, washing hands after using the toilet
How is tuberculosis spread? How can the spread be reduced?
Spread - airborne
Can be reduced by - ventilate buildings, isolate infected people, diagnose quickly and treat with antibiotics, vaccination
How is malaria spread? How can the spread be reduced?
Spread - by animal vectors
Can be reduced by - prevent mosquitos biting people
How is Chalara ash dieback spread? How can the spread be reduced?
Spread - airborne
Can be reduced by - removing infected plants
How are stomach ulcers spread? How can the spread be reduced?
Spread - oral transmission
Can be reduced by - cook food to kill bacteria, washing hands before preparing food
How is Ebola spread? How can the spread be reduced?
Spread - bodily fluids
Can be reduced by - isolating infected people, wear protective clothing
What is the process of the lytic cycle?
- Virus binds to host cell and injects its genetic material
- Virus using the cells machinery to make viral proteins
- These proteins make virus particles which are released in lysis (when the host cell bursts)
- The new viruses go on to inject other cells and the cycle repeats
What is the process of the lysogenic cycle?
- The virus uses restriction enzymes to insert its DNA into the host cells DNA
- The host cell replicates and the viral DNA is also copied in this process
- Then the lytic cycle begins
What are some physical barriers of plants?
- Thick cellulose cell wall – impermeable to many pathogens
- Thick waxy cuticle
- Layer of bark
- Closed stomata
What are some chemical barriers of plants?
- Poisons in their cells to deter pests that try to eat them
- Chemicals that kill pathogens such as bacteria and fungi
How can plant chemical barriers used in medicine?
- Antimicrobial compounds can be used in drugs such as antibiotics
What type of pathogen is chlamydia?
Bacterium
What are some visible symptoms of plant disease?
- Overgrowth or under-development of a part of a plant e.g. swelling on roots or smaller leaves the usual
- Dark spots or discolouration on leaves
- Death of parts of a plant or leaf loss
What must be considered during distribution analysis?
- How many plants are affected? If all are it’s probably environmental factor
- Where are diseased plants found? All in one place or over a large area?
- Is just one species of plant affected or several? It may be a species specific pathogen
- Do the symptoms of the plant change over time?
What techniques are used in the lab to identify a disease?
- Microscopic examination of plant material for signs of pathogens
- Antibodies to test for the presence of a pathogen
- Genetic testing to identify any pathogens found
- Soil sample testing to rule out soil factors
- Trying to grow pathogens on nutrient medium (agar jelly) to produce a large sample for identification
What are some human physical barriers and how do they protect against pathogens?
Mucus - goblet cells create mucus which trap pathogens before they reach the lungs
Cilia - on ciliated epithelial cells, move in a wave like motion to move mucus from lungs to back of throat
Unbroken skin - too thick for most pathogens to get through
What are some human chemical defences and how do they protect against pathogens?
Lysozyme - enzyme in tears saliva and mucus, kills bacteria by digesting the cell walls
Hydrochloric acid - kills bacteria in food and drink
How do phagocytes damage pathogens?
- Surround, bind to and engulf them
 - The enzymes in the phagocytes break down the pathogen
What are the stages of lymphocytes responding to pathogens?
- Each pathogen has a unique antigen on its surface
- A lymphocyte with an antibody that fits the antigen is activated
- Once activated, it divides many times to produce clones of identical lymphocytes
- Some produce many antibodies which stick the pathogens together, so its easier for phagocytes to engulf them
- Other lymphocytes stay in the blood as memory lymphocytes, to respond immediately if the same pathogen returns
What is the process of vaccination?
- Vaccine contains antigens from the pathogen, often dead or weakened pathogens
- Lymphocytes produce antibodies against pathogen and memory lymphocytes
- If they get the real pathogen, memory lymphocytes will give a rapid second response
- So they’re unlikely to become ill
What are the advantages of immunisation?
- Immunity is produced without being ill
- Immunity lasts a while, often for life
- If most people are immune, the few that are unvaccinated are also less likely to catch the disease (herd immunity)
What are the disadvantages of immunisation?
- Some people suffer from mild reaction (e.g. swelling soreness)
- Very rarely, a person has a major harmful reaction
Why can antibiotics only be used to treat bacterial infections?
They inhibit cell processes in the bacteria but not in the host organism (which viruses use)
What are some aseptic techniques when working with micro organisms?
- Sterilising dishes and culture media in an autoclave or UV light
- Sterilising inoculating hoops in a flame
- Sealing the lid of Petri dishes with tape (but not completely to allow anaerobic bacteria to grow)
How do you investigate the effect of antibiotics?
- Soak filter paper discs in variety of solutions
- Prepare petri dish with agar gel and sterilise
- Use sterile forceps to place discs on the plate and label
- Do same with control disc
- Tape lid to base of dish without completely stealing it
- Incubate for a few days at 25° C
- Measure radius of zone of inhibition and calculate area (pi x r² )
What are the stages of drug testing?
Preclinical testing – tested using computer models and human cells grown in the lab then live animals, tests the efficacy and side effects
Clinical trials: Stage one – tested on healthy volunteers in a small dose to test if it’s harmful
Clinical trials: Stage two – tested on patients to find the most effective dose, some are given a placebo, may be single-blind or double-blind trial
How are monoclonal antibodies produced?
- Take B lymphocytes from mice - stimulated to produce a specific antibody, but don’t divide
- Combine with tumour cells - dont make antibodies but divide rapidly
- These form a hybridoma cell, which have both characteristics
How are monoclonal antibodies used in pregnancy tests?
- A hormone called HCG is in pregnant womens’ urine
- The first section of the stick has mobile antibodies, specific to hCG, attached to blue beads
- The second section has stationary antibodies also specific to hCG, that are stuck down to the stick
- You urinate on the first section
- If HCG is present, it will bind to the mobile antibodies
- They are carried in the flow of liquid to the second section where they will bind to the stationary antibodies
- As all the blue beads are collected here, a blue line will be visible, indicating pregnancy
How are antibodies used in locating cancer cells?
- They can be modified so they will bind to the antigens on cancerous cells
- When they bind to the cancer cells, they clump them together
- Making it easier to identify cancerous tumour which can then be treated or moved
How are antibodies used to locate the position of blood clots?
- They are modified so they will bind to the molecule you’re looking for
- They are also bound to a fluorescent dye
- The antibodies will bind to the molecules if they’re in the sample and the dye is observed
In what ways can monoclonal antibodies treat cancer?
By carrying drugs – they can only bind to cancer cells, reducing risk to healthy cells and meaning less drug needed
Specifically bind to tumour markers to stimulate an immune response
What is the advantage of using monoclonal antibodies to target specific cells?
They can only bind to specific cells so healthy cells are not affected
What is the calculation for BMI?
Weight (kg) / Height² (m)
How do you calculate waist : hip ratio?
Waist / Hip
What are some lifestyle changes people can make to treat CVD?
- Take more exercise
- Reduce the amount of saturated fat and salt in their diet
- Stopping smoking
- Reducing alcohol intake
What are the advantages and disadvantages of lifestyle changes in treating CVD?
Advantages:
- No side-effects
- May reduce chances of getting other health conditions
- Cheapest option
Disadvantages:
- Takes a while to work
- May not be effective
What are the types of medication used to treat CVD?
Statins - reduce cholesterol
Beta blockers - lower blood pressure
What are the advantages and disadvantages of medication for CVD?
Advantages:
- Start working immediately
- Cheaper and less risky than surgery
Disadvantages:
- Need to be taken regularly for awhile
- Some side-effects (kidney failure for statins)
- Not suitable for some people (with medications, with liver disease or pregnant)
What are the types of surgery for treating CVD?
Stent - wire frame inserted into blocked or narrowed arteries
Heart bypass - new blood vessel is inserted to bypass blocked coronary arteries
What are the advantages and disadvantages of stents to treat CVD?
Advantages:
- Lasts a long time
- Quick recovery time
- No general anaesthetic needed
Disadvantages:
- Risks during operation, infection or heart attack
- Risk of blood clot near the stent
What are the advantages and disadvantages of hearts bypasses for treating CVD?
Advantages:
- Long-term solution
Disadvantages:
- Risk of infection in surgery
- Surgery is expensive
