module 4 - 12.7 preventing and treating disease

Question 1

what is natural immunity?

Answer 1

• immunity that occurs naturally in the body

Question 2

hat is natural active immunity?

Answer 2

• when pathogen is met for the first time, immune system is activated and antibodies are formed - destructs antigen
• immune system produced T and B memory cells so if pathogen is met again, immune system can immediately destroy it

Question 3

why is it natural active immunity known as active?

Answer 3

because the body has self acted to produce antibodies and/or memory cells

Question 4

what is natural passive immunity?

Answer 4

• new born babies cannot make antibodies
• some antibodies cross the placenta from the mother so has some immunity at birth
• milk (colostrum) has high antibodies, infants gut allows these glycoproteins into bloodstream without being ingested

Question 5

what is artificial passive immunity?

Answer 5

antibodies are formed in one individual, extracted and then injected into bloodstream of another

Question 6

what is artificial active immunity?

Answer 6

immune system of the body is stimulated to make its own antibodies to a safe form of antigen (vaccine) which is injected into the bloodstream

Question 7

what are the steps of artificial active immunity?

Answer 7

1. pathogen is made safe so the antigens are intact but there’s no risk of infection
2. small amounts of safe antigen are injected into blood
3. primary immune response is triggered by foreign antigens, body produces antibodies & memory cells if infected with live pathogen
4. contact with live pathogen - secondary response triggered & you destroy pathogen rapidly

Question 8

what may vaccines contain?

Answer 8

• killed or inactive bacteria and viruses
• weakened strains of bacteria or viruses
• isolated antigens extracted from pathogen
• genetically engineered antigens

Question 9

what is an empidemic?

Answer 9

when a communicable disease spreads rapidly to a lot of people at a local or national level

Question 10

what is a pandemic?

Answer 10

when a communicable disease spreads rapidly across a number of countries (worldwide)

Question 11

what can prevent epidemics?

Answer 11

mass vaccination but must be changed to remain effective

Question 12

what is herd immunity?

Answer 12

when a mass number of people have been vaccinated - minimal opportunity for outbreak to occur

Question 13

what is the impact of medicines?

Answer 13

• penicillin - cures bacterial diseases
• computer programmes can build up to 3D models of key molecules , pathogens and antigen systems
• analysis of genomes and pathogens - target drugs

Question 14

what is the source and action of penicillin?

Answer 14

SOURCE - extraction originally from mould
ACTION - antibiotic against many common bacterial diseases

Question 15

what is the source and action of docetaxel/paclitaxel?

Answer 15

SOURCE - yew trees
ACTION - treatment of breast cancer

Question 16

what is the source and action of aspirin?

Answer 16

SOURCE - sallow (willow) bark
ACTION - painkiller, anticoagulant, anti-inflammatory

Question 17

what is the action and source of prialt?

Answer 17

SOURCE - venom of cone snail
ACTION - new pain-killing drug

Question 18

what is the source and action of vancomycin?

Answer 18

SOURCE - soil fungus
ACTION - antibiotics

Question 19

what is the source and action of digoxin?

Answer 19

SOURCE - extracted from foxgloves
ACTION - powerful heart drug, treats atrial fibrillation & heart failure

Question 20

what are pharmogenetics?

Answer 20

• analysing human genome rapidly and cheaply
• science interweaving knowledge of drug actions with personal genetic material

Question 21

what is synthetic biology?

Answer 21

• techniques of genetic engineering
• enables use of bacteria as biological factories
• redesigning organisms for useful purposes

Question 22

what is selective toxicity?

Answer 22

when antibiotics interfere with the metabolism of the bacteria without affecting metabolism of the human cells

Question 23

how are antibiotics becoming less effective?

Answer 23

bacteria becomes more exposed and more resistant to antibiotic
- may also come from over prescribing antibiotics

Question 24

what is the development of antibiotic resistant bacteria?

Answer 24

random mutations occur within bacteria and produce one not affected by drug, that will then survive & reproduce, passing on antibiotic resistance to daughter cells

Question 25

what is MRSA?

Answer 25

• bacterium carried by up to 30% of population on skin or in nose
• in body - causes boils, potentially fatal septicaemia
• was treated effectively with methicillin - produced mathicillin-resistant strains

Question 26

what is C. difficile?

Answer 26

• bacterium in guts of 5% of population
• produced toxins that damage linings of intestines - leads to diarrhoea & bleeding
• when commonly used antibiotics kill off ‘helpful’ bacteria it survives & reproduced rapidly

Question 27

how can antibiotic resistant infections be reduced?

Answer 27

• minimising use of antibiotics, ensuring every course of antibiotics is completed
• good hygiene in hospitals, care homes & in general