B10 & B14 - diseases & immunity, drugs Flashcards
define disease
harmful deviation from the normal structure or function of the organism
define pathogen & eg
a disease causing organism or virus
eg, bacteria, virus, fungi, parasite
features of a virus
-drawing: circle with a circle in with a coil, spikes around outer cirlce
-coil = genetic material
-space btw circles = protein coat/ capsid
-spikes = spike protein
facts about viruses
-200 - 400 nanometers (1/10 bacteria size, 1/100 human animal cell size)
-contains genetic info (DNA/ RNA)
-has protein coat/ spike protein
-no nucleus, cytoplasm, no cell = non- living
define a transmissible disease
-disease caused by a pathogen & can be passed from 1 host to another
example of transmissible diseases
eg. covid, rabis, AIDS, HFMD, salmonella
define a non- transmissible disease
-disease not caused by a pathogen
example of non- transmissible diseases
eg. coronary heart disease, diabetes, Parkinson, most cancer, (anything genetic)
Methods of Transmitting diseases
-direct contact
-indirect contact
transmitting diseases by direct contact & example
-blood (blood transfusion/ sexual contact) eg. HIV
-mucus/ saliva (droplet infection) eg. covid
transmitting diseases by indirect contact & example
-contaminated surfaces eg. covid
-contaminated food eg. salmonella
-contaminated water eg. cholera
-animals spread diseases eg. malaria
how to control spread of diseases
-a clean water supply
-hygienic food preparation
-good personal hygiene
-waster disposal
-sewage treatment
how does a clean water supply control the spread of diseases
process: good water treatment
prevention: removes pathogens, prevent spread of pathogen, prevent drinking contaminated water
how does hygienic food preparation control the spread of diseases
process: wash your hands, cover food
prevention: removes pathogen, prevent flies on landing on food
how does good personal hygiene control the spread of diseases
process: wash hands with soap, use disposable tissue
prevention: removes pathogens, prevent spread of pathogen
how does waster disposal control the spread of diseases
process: cover rubbish bins
prevention: prevents flies/ rats from spreading disease
how does sewage treatment control the spread of diseases
process: plumbing, treat raw sewage, put chlorine
prevention: keeps sewage away form people, removes/ kills pathogens
ways the body prevent pathogen entry & how they work
-skin - impermeable to pathogens
-hairs in nose - hairs trap air particles that could contain pathogens
-mucus - mucus traps pathogens
-stomach acid - HCl kills pathogens
type of barriers in body to prevent pathogen entry
-skin - mechanical
-hairs in nose - mechanical;
-mucus - mechanical/ chemical
-stomach aicd - chemical
what does white blood cells do if pathogen enters body
-phagocytes - phagocytosis
-lymphocytes - produce antibodies
define antigen
-a protein on the cell membrane which identifies a cell
-pathogens have foreign antigens
where are antigens found
on surface of cell membrane
define antibodies
Y shaped proteins that destroy specific pathogens/ antigens
what do antigens trigger
activates antibody produciton
define active immunity
foreign antigen stimulates the production of specific antibodies & memory cells are made which remain in the blood
what is an antibody specifity
antibody has a complementary shape that only fits 1 antigen
how to get active immunity
-be exposed to antigen to make your own antibodies & memory cells
define passive immunity
-receiving antibodies, rather than making them ourselves
-no memory cells are made
how is passive immunity done
-breastfeeding/ placenta
-some vaccinations
how does vaccination help achieve active immunity
-inject dead/ weakened pathogens or just antigen - does not cause the disease
-lymphocytes recognize foreign antigen
-lymphocytes product antibodies against pathogen
-lymphocytes produce memory cells which stay in the blood
-second time of exposure, you make antibodies faster & more = don’t get sick
why do you get the same sickness twice
-the pathogen mutates so its antigen changes too
-the antibodies don’t work on the diff. antigen
how does vaccination control the spread of diseases
-provided protection to the population
-if everyone is vaccinated, pathogen cannot be spread
-vaccinated people cannot spread/ pass on pathogen
-vaccination can achieve active immunity
describe how vaccination can prevent the spread of diseases
-active immunity
-dead/ weakened pathogens injected
-antigen triggers antibody production by lymphocytes
-memory cells are reproduced
-no host for pathogen to spread to
define drug
any substance taken into the body that modifies or affects the chemical reactions in the body
define antibiotics & example
medicinal drugs that kill bacteria
eg. penicillin
how to antibiotics work
-prevent bacterial cell wall form developing
-prevent ribosomes & enzymes from working
-prevent bacteria form reproducing
why do antibiotics not kill viruses
-viruses don’t contain bacterial cells/ cell wall/ enzymes/ ribosomes
cause of viral infections
-viruses
-so you can’t treat them with antibiotics (antibiotics are only effective against bacteria)
reasons that antibiotics can lose their effectiveness
-antibiotics used to treat viral infections
-large scale use of antibiotics as a disease prevention
-mutations occur in the bacteria
how does bacteria develop antibiotic resistance
-mutation occurs
-most bacteria are not resistant
-after exposure to antibiotics, non- resistant bacteria die
-resistant bacteria survive & can multiply & pass their resistance by plasmid to the remaining non- resistant bacteria
define MRSA
bacteria that are resistant to most antibiotics
way antibiotic resistance can be prevented
-complete course of antibiotic
-only use antibiotics when prescribed
-don’t overuse antibiotics
-farmers should not use antibiotics to prevent infenction
