BIOLOGY - Disease, defence, and treatment Flashcards
What creates antibodies and what do antibodies do?
produced by lymphocytes in the immune system. Recognise and attach to a specific antigen on a pathogen.
what does the word antigen mean?
a chemical on the surface of a pathogen that is recognised by the immune system.
What is an antibiotic?
a drug that is used to kill bacteria. examples include penicillin.
what is a phagocyte?
a type of white blood cell that engulfs and destroys pathogens.
what is a lymphocyte?
a type of white blood cell that produces antibodies. it can differentiate into memory cells and plasma cells.
what is a vaccine
deliberate exposure to a harmless version of a pathogen that triggers an immune response without giving you the disease. Gives you immunity for that certain disease
what does immunity mean
resistance to a specific pathogen.
what does the word microorganism mean?
a microscopic organism. includes bacteria, viruses, fungi and protoctista.
what is a pathogen?
a microorganism which can cause disease.
what are the 4 types of microorganism?
-bacteria
-viruses
-fungi
-Protists, also referred to as protoctista
most microbes are harmless and many can perform vital functions, give two examples
-bacteria - yoghurt, cheese etc, digesting food in gut
-fungi - in yeast which makes bread and alcohol
what is the name given to microorganisms that cause disease?
pathogens
list 4 common diseases, and the microorganisms which cause them
• tuberculosis - caused by bacteria
• flu- caused by virus
• athletes foot- caused by fungi
• malaria - caused by protists
name 4 ways diseases can be spread
-contact
-body fluids
-food and water
-insects
how can you prevent the spread of disease?
(6 ways)
-cook food thoroughly
-hygiene - wash hands after going to the toilet
-vaccination
-taking drugs and medicine
-avoid drinking contaminated water, etc.
-anti bacterial sprays, etc.
name the 7 parts of a bacteria structure
-cell wall
-cell membrane
-cytoplasm
-chromosome
-slime capsule
-flagella
-plasmid
whats the function of a cell wall in a bacteria structure
protection and maintaining the cell shape
whats the function of a cell membrane in a bacteria structure
controls substances entering and leaving the cell
what is the function of the cytoplasm in a bacteria structure
where chemical reactions occur within the cell
what is the function of the chromosome in a bacteria structure
contains DNA. Information for day to day activities such as growth is stored
what is the function of the slime capsule in a bacteria structure
prevents bacteria dying out. allows bacteria to stick together.
what is the function of the flagella in a bacteria structure
allows the bacteria to move
what is the function of the plasmid in a bacteria structure
small circular pieces of DNA
what two parts does a diagram show what a virus has?
-protein coat
-DNA or RNA
why is a virus not described as a living thing?
can’t carry out basic life processes, eg. growth or respiration.
how many times smaller is a virus compared to a bacterium
10x smaller
give 3 ways a virus is different in structure to a bacterium
(if you want, try think of 6, there are 6 answers)
- no cell wall
- no plasmid
- no flagella
additional 3.
- no nucleoid
- no slime capsule
- no cell membrane
list 6 diseases and ways to prevent them
obesity - diet low in fat and sugar/regular exercise
heart disease - regular exercise
high blood pressure - diet low in salt/minimise stress
lung cancer - quit smokin/dont smoke
liver disease - dont drink alcohol
measles, mumps, TB - vaccinations
list another 6 diseases and how to treat em
chest or ear infection - antibiotics
cancer - radiotherapy or chemotherapy or surgery
anaemia - iron tablets/supplements like iron injections
haemophilia - blood products/ vitamin k/ clotting factors
diabetes - low sugar, hormone injections like insulin
cystic fibrosis - gene therapy
name the 5 defences that we have to help against pathogens? and what do they do
- goblet cells - make mucus which traps microbes. Cilia move the mucus up and out of the lungs to the top of the throat.
- stomach acid - kills the microbes as they enter the stomach
- intact skin - forms a barrier against pathogens. pathogens have to compete against the body’s natural population of microbes and they find it difficult to establish. Also sebum is an antiseptic.
- blood clots - seal wounds to prevent entry of pathogens.
- white blood cells, phagocytes and lymphocytes
there are protein molecules on all cell membranes which white blood cells will recognise, what are they called?
How do white blood cells recognise em?
Antigens.
• White blood cells recognise antigens on our own body cells
• When foreign antigen detected
• e.g. surface of a pathogen
• They will destroy the pathogen
What are the 2 types of white blood cells?
Also describe their structure
PHAGOCYTES -
• No particular shape
• Lobed nucleus
• Cytoplasm forms pseudopodia (little arm things that help surround bacterium to engulf and destroy it, check yo book)
LYMPHOCYTES -
• Large rounded cell
• Large nucleus
• Antibodies around it
what does a phagocyte do? (one of the two types of a white blood cell)
• Recognises antigens on the bacterium (cuz it’s foreign)
• Engulfs it by producing pseudopodia (cytoplasm arms), which goes around the pathogen
• Microbe trapped in vacuole inside phagocyte
• Digested and destroyed there
what does the lymphocyte do? (one of the two types of a white blood cell)
part 1
- one lymphocyte with specific antibody shape for the invading antigen is activated.
- lymphocyte divide by mitosis.
- some of the daughter cells form plasma cells
- others form memory cells.
- plasma cells will secrete antibodies that combine with the antigens to destroy them.
what does the lymphocyte do? (one of the two types of a white blood cell)
part 2
- memory cells stay in blood
- if antigen enter body again
- mem cells will respond + divide by mitosis
- to form more plasma cells + make more mem cells
- this 2nd response much faster than 1st response
- cuz it had mem cells this time
- mem provides immunity following a natural infection and after a vaccination
1) name the two cells that a lymphocyte will divide into during cell division
2) name the type of cell division
3) describe the structure of the two cells
1) plasma cells and memory cells
2) type of cell division is mitosis
3) plasma cell = literally same as lymphocyte I think, big nucleus and stuff with antibodies on the surface to destroy pathogens with.
memory cells = same too but they have no antibodies since they are memory cells
describe the primary (first) response if a pathogen attacks
and also the secondary (second) response if the same pathogen attacks
primary
-slower process of defeating pathogen
-less antibodies are made
-you will feel ill and have symptoms
secondary
-faster process of defeating pathogens
-more antibodies produced
-less symptoms or no symptoms
how were vaccines first discovered?
Edward Jenner did a bunch of bullshit and it worked.
idk if you need to know it but
he was an English doctor in the 18th century and first carried out experiments on vaccinations to prevent small pox. he observed dairymaids who milked cows caught a mild disease called cowpox and after that they did not catch smallpox.
Jenner obtained some pus from a cowpox scab and scratched some of it into the arm of an 8 y/o boy. the boy got cowpox but soon recovered, Jenner then transferred pus from a smallpox victim into the boys arm but the boy did not catch smallpox
exlpain how edward jenners vaccine worked
idk if you need to know this
people infecected with cowpox survived and produced memory cells, the antigens on the smallpox are simlar as antigens of cowpox, when infected with cowpox, the virus is recognised by memory cells, and th pey divide rapidly and produce plasma cells.
what are advantages of vaccination?
• less chance of a disease being spread and prevents epidemics
• fewer people with disease = less deaths
• protects the individual from disease and illness
what are the disadvantages of a vaccination
• unexpected side effects or allergies
• if vaccine compulsory, goes against personal rights
who was the person who first discovered antibiotics? and how?
alexander Fleming - he saw clear areas around a fungus that had contaminated a dish of bacteria, and he realized that the fungus was making a substance to kill the bacteria, we now know this has penicillin
name the two people who purified penicillin?
Florey and Chain - they developed it as a cure for bacterial infections.
how do bacteria get resistant to antibiotics
• bacterial strains can develop resistance to antibiotics
• due to natural selection
• in large population of bacteria
• some cells not affected by antibiotic
• and will survive
• thus they reproduce
• producing more antibiotic resistant bacteria
what does MRSA stand for
methicillin-resistant staphylococcus aureus.
very dangerous because it is resistant to most antibiotics.
medicines are used to treat disease, pain and injury
name a benefit and a risk
benefit = its a pain killer
risk = • can be addictive
• cause side effects like nausea or stomach pains, etc.
drugs change various chemical processes in peoples bodies so that they become dependent on them, what word is used to describe this dependance
addiction
when a person tries to give up a drug they are addicted to, they can suffer symptoms, like having cravings or having poor concentration, what term is used to describe these symptoms
withdrawal symptoms
when a scientist develops a drug to treat disease, it must be tested for side effects, etc.
there are 4 stages, describe them.
stage 1 - computer models used to stimulate a human response to a drug. Drugs tested in laboratory. Tested on live cells and on animals.
stage 2 - drugs that show good signs in laboratory are tested on small number of healthy humans.
stage 3 - drug is tested on 100 humans who suffer from the disease that that drug is meant to cure.
stage 4 - drug is tested on several hundreds of sufferers alongside an existing drug for the disease, testing is extensive and large scale.
what is a placebo
a pill or medicine that doesn’t contain the active drug
suggest one reason a placebo is used
avoid bias, and fair comparison
what animals are commonly used for drug testing
mice/rats
who asks for the tests to be done?
pharmaceutical companies
why are drug tests carried out
• look for side effects
• is it safe?
• what’s right amount of dosage for safe uses
some people argue against animal testing
state 2 arguments for and against
for
-help push out new drugs to help save lives
-computer models aren’t advanced enough to ensure safety
against
-animals can react differently to humans so its not a valid test
-alternatives are available
