12. antibiotics Flashcards
what are antibiotics?
antibiotics
chemicals that kill or inhibit growth of bacteria. used to treat bacterial infections without damagig human body cells.
thestory behind penicillen
and the risks of using antibiotics
- first antibiotic to be isolated much to the widespread use during ww2
- treatment with antibiotics has been easy and effective seeing a large drop in death rate from bacterial diseases
- despite usefulness : side effects, allergic reactions and antibiotic resistence are all big risks
what is
pharmacogenetics?
the right drug for the right patient the right dose
sources of medicine and examples
- fungus- penicilun
- bacteria - used to make doxycycline and antibiotic
- trees- asprin from willow trees
- fox glove- digoxin heart medication
The future of medicine
- synthetic biology - tech and design to make atrificial proteins cells and microrganisms
- personal medicines - pharmacogenetics can be tailored to an individuals DNA so if you entire geneome is available doctors can predict and pescribe the most effective drugs
two antibiotic resistant strains of
bacteria
- MRSA- causes serious wound infections and is resistant to several antibiotics used to be effectivley treated with meticillin
- C.difficile- infects the digestive system and produces toxins that lead to diaroeah fevers. when harmless bacteria in gut are killed off by antibiotics it flourishes
three measures to tackle antibiotic resistance
- minimising antibiotic use
- finsihing a full course
- good hygine practise
how does antibiotic resistance arise?
- there is genetic variation withing a population of bacteria
- gentic variation make some bacterita naturally resistant to the antibiotics
- this ability to resist is a advantage it can survive if a host is treated with a course of antibiotics and it loses its competition so reproduces rapidly t
- leading to its resistant allele to be passed to its offspring by natural selection
- leading to superbugs
what parasite causes malaria?
plasmodium
Outline the action of opsonins.
increase likelihood of phagocytosis (1)
idea that binds to pathogen and phagocyte /
macrophage (1)
What is meant by the term autoimmune disease?
abnormal immune response (1)
against tissues normally in the body (1)
Scientists often use natural substances to help them develop specific new medicines.
State two possible sources of such natural substances.
- plants
- microrganisms
Outline the processes that lead to the production of antibodies against an unfamiliar bacterium.
Explain how helper T cells act to speed up these processes.
three from
B cells / lymphocytes, have, antigen receptor /
carry antibody, on surface, specific /
complementary to, only one antigen (1)
selected / activated, B cell, proliferates /
clones / divides by mitosis (1)
forms / differentiates into, plasma / effector,
cells (1)
which secrete antibodies specific /
complementary, to antigen (1)
two from
(helper T cells) stimulated by antigen-r
presenting cells (1)
release, cytokines / interleukin 2 (1)
stimulate B-cell, proliferation / mitosis / clonal
expansion (1)
List two vulnerable groups of people for whom you would advise doctors to prescribe antibiotics although they are not yet showing symptoms of the new disease.
two from
babies / infants (1)
elderly / infirm (1)
immuno-compromised / on
immunosuppressant drugs / HIV positive (1)
known to have been exposed (to the infection)
Discuss the implications of the over-use of antibiotics when people do not show symptoms.
two from
(antibiotic is) selective pressure (1)
(bacterial) gene pool / AW, has variation (1)
(only) some bacteria have resistance / some
bacteria are more resistant than others (1)
two from
when exposed (to antibiotic) most-resistant
survive (1)
surviving bacteria continue to reproduce to
make a resistant population (1)
idea that over many generations there is an
increase in proportion of resistant bacteria
(under continued antibiotic pressure) (1)
antibiotic becomes ineffective / new antibiotic
needed (1)
