Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Biology Topic 5 - health > fighting disease > Flashcards

fighting disease Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Biology flashcards Biology 101 flashcards
1
Q

what is immunity?

A

the ability of the human body to defend itself against disease-causing organisms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what are physical and chemical barriers an example of?

A

first line of defence (non specific)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what are examples of physical barriers in human beings?

A

Physical : the skin acts as a barrier against pathogens, unless it is damaged
if it is damaged, the platelets in the blood clot the blood to seal the skin, preventing the entry of pathogens
hairs in the nose waft away pathogens and dirt
cells in the trachea produce mucus (goblet cells) to trap pathogens and dirt, while cilia waft these to the top of the throat so they can be digested, instead of reaching the lungs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what are examples of chemical defences in human beings?

A

hydrochloric acid in the stomach has a very low pH to kill pathogens
lysozymes in tears kill bacteria on the surface of the eyes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what are the 2 main types of white blood cell involved in the immune response?

A

b lymphocytes
phagocytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what is phagocytosis?

A

involves phagocytes engulfing and digesting pathogens
as no specific antibodies are produces in response to the presence of a pathogen, this is a non specific immune response

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

function of B lymphocytes

A

they produce specific antibodies (complementary) to the antigens on a pathogen’s surface
these bind together, making the pathogen more noticeable to other white blood cells, who destroy it
this is a specific immune response
memory cells are also produced in response, which will recognise the same antigen if it infects again

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

function of memory lymphocytes

A

recognise antigens that have infected the body before, and if this happens they will stimulate the production of lots of antibodies against it to destroy it; so many people are usually free from infection before they can even experience symptoms
makes secondary immune response faster

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

immunisation means…

A

the injection or inactive/pathogens into the body to provoke an immune response

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

describe the process of immunisation

A
  • dead/inactive pathogens are injected into the blood (through the arm)
  • even though they are inactive, they are still antigenic, so while they’re harmless, white blood cells will still produce antibodies against them, to destroy them
  • memory lymphocytes are also produced which will recognise this antigen if it infects the body again, and will stimulate the production of lots of antibodies to destroy the pathogen
  • makes a person much less likely to get infected with that disease
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

pros and cons of immunisation

A

pros; prevents epidemics, heard immunity, has virtually wiped out diseases like smallpox
cons; sometimes immunisation programmes are ineffective, and some people can have severe reactions to vaccines such as seizures

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

define monoclonal antibodies

A

identical copies of a single b lymphocyte

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

how can we make monoclonal antibodies?

A
  • inject a mouse with a chosen antigen
  • collect B lymphocytes produced my the mouse in response to the antigen
  • fuse these with myeloma cells
  • this is because while B lymphocytes produce antibodies they divide very slow, whereas tumour cells can divide rapidly
  • this makes a hybridoma, which is cloned to get lots of identical cells, which produce monoclonal antibodies
  • monoclonal antibodies are collected and purified
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

uses of monoclonal antibodies

A

pregnancy tests
detecting blood clots
detecting and treating cancers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

how are monoclonal antibodies used in pregnancy tests?

A

a hormone called HCG is ONLY found in the urine of pregnant women
the test stick has blue beads and antibodies to HCG on it while the strip has more antibodies stuck to it so they can’t move
if the woman is pregnant, when she urinates on the stick, the HCG binds to the antibodies on the blue beads, so the urine moves upwards carrying the hormone and the beads
beads and hormone bind to the antibodies on the strip, and as the blue beads are stuck to the strip, it turns blue, indicating pregnancy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what do we call the antigens on the surface of cancer cells?

A

tumour markers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

how are monoclonal antibodies used to detect cancers?

A
  • label the monoclonal antibodies using a radioactive element
  • given to a patient through a drip, goes into the blood and travels all around the body
  • when the antibodies come into contact with cancer cells, they bind to the tumour markers on their surface
  • picture of the body is then taken using a camera that detects radioactivity, and anywhere there are cancer cells will show up as a bright spot
  • doctors can then tell if the cancer is spreading, what size it is, and where it is
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

how are monoclonal antibodies used to treat cancer?

A
  • monoclonal antibodies are attached to anti cancer drugs
  • they are given through a drip, and enter the blood before travelling around the whole body
  • the antibodies will only kill cancer cells as they only bind to tumour markers
  • drug kills cancer cells but not normal cells near the tumour
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

why are using monoclonal antibodies to treat cancer better than other methods such as chemotherapy?

A

monoclonal antibodies will only bind to tumour markers, meaning they will only kill cancerous cells and not normal cells near the tumour unlike chemotherapy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

how does a blood clot form?

A

proteins in the blood join together to form a solid mesh

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

how are monoclonal antibodies used to treat blood clots?

A
  • attach radioactive element to the monoclonal antibodies
  • monoclonal antibodies are given to patient through a drip
  • these travel around the rest of the body and bind to the antigens on the proteins of the blood clot
  • use special camera that detects radioactivity to take a picture
  • blood clot/s will appear as bright spot/s
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

why do newly discovered drugs have to go through testing procedures before they can be prescribed to the general public?

A

to make sure they are safe and effective to use, not toxic

23
Q

what are the 3 main stages of testing for newly discovered drugs?

A

preclinical testing on human cells
preclinical testing on live animals
clinical testing on human volunteers

24
Q

what was the first antibiotic discovered and who discovered it?

A

penicillin - Alexander Fleming

25
Q

preclinical testing 1

A

involves testing on human cells and tissues in a laboratory, also using computer models
allows efficacy and possible side effects to be tested

26
Q

preclinical testing 2

A

testing on live animals
helps us to determine its efficacy, its toxicity and the best dosage to use

27
Q

clinical testing

A

if the drug passes tests on animals, then it’s tested on human volunteers after
first, its tested on human volunteers to make sure it doesn’t have any harmful side effects
if this is okay, then we test on people suffering from the illness; optimum dose is found

28
Q

what are placebos

A

substances that look like a drug tested but doesn’t do anything (like a sugar pill)

29
Q

why do doctors use placebos?

A

divide the patients into 2 groups; one is given the new drug, while the other group is given a placebo
allows them to investigate the actual difference that a drug makes; placebo effect

30
Q

what is a placebo effect?

A

when the patient expects the treatment to work and feels better, even though the treatment isn’t doing anything (the sugar pill has no effect)

31
Q

blind trials

A

the patient doesn’t know whether they will receive the placebo or the drug

32
Q

double-blind trials

A

neither the patient nor the doctor knows if the patient will receive the placebo/drug to prevent the bias of the doctors effecting the results

33
Q

why is peer review of a drug necessary?

A

to prevent false claims

34
Q

what happens when a drug has passed all these tests?

A

still needs to be approved by a medical agency before it can be used to treat patients so the drugs are effective and safe as possible

35
Q

case study - thalidomide

A
  • 1950s, tested as a sleeping drug, approved for that use
  • found to have helped relieve the morning sickness of pregnant women
  • hadn’t been tested for this but it was still used; however, people didn’t know that it could pass through the placenta and affect the foetus, causing abnormal limb development
  • about 10,000 babies were affected, almost half of them survived
36
Q

define antibiotics

A

drugs used to treat bacterial infections, by inhibiting the processes that occur in bacterial cells, but not in the host organism

37
Q

how do antibiotics work?

A

inhibit the processes that occur in bacterial cells
e.g. penicillin inhibits the building of bacterial cell walls, which prevents the bacteria from dividing and eventually kills them, without damaging the cells in the human host

38
Q

different antibiotics target ………….. types of …………….

A

different antibiotics target different types of bacteria

39
Q

why do antibiotics have no effect on viruses?

A
  • viruses aren’t cells; they don’t have cell walls or any mechanism for growth/reproduction so antibiotics have no effect on them
  • viruses can only replicate using the host cell’s machinery INSIDE the cell and antibiotics do not affect host cells
40
Q

what is the name of the process that involves the reproduction of bacteria?

A

binary fission

41
Q

what are the optimum conditions for bacterial growth?

A
  • moisture
  • suitable pH
  • time
  • nutrients
  • higher temperature
42
Q

what are the 2 main ways to culture bacteria? (the growth mediums)

A
  • agar jelly plate
  • nutrient broth
43
Q

in a lab at school, why are agar jelly plates incubated at low temperatures (max 25 degrees)?

A

higher temperatures can encourage the growth of foreign, dangerous pathogens

44
Q

difference between antibiotic and antiseptic

A

antibiotic kills bacteria inside the body
antiseptic kills bacteria outside the body

45
Q

how to make an agar jelly plate

A
  • pour hot agar jelly into a plastic dish called a petri dish
  • let it set/cool
  • use an inoculating loop to evenly spread bacteria across the jelly
46
Q

how can we investigate the concentrations of antiseptic on bacterial growth?

A
  • place paper discs which have been soaked in different concentrations of antiseptic onto the jelly (leave space between each one)
  • antiseptic should diffuse into the agar jelly; antibiotic resistant strains will continue to grow around the discs, whereas the non resistant strains will die
  • use a control soaked in sterile water to ensure the results are valid
  • leave plate for 48 hrs at 25 degrees
  • compare the areas where no bacteria are growing around each disc (zone of inhibition)
    the larger the zone of inhibition, the more effective the antiseptic
47
Q

what aseptic techniques should be used during this practical?

A
  • petri dish and growth medium must be placed in an autoclave before use (machine which uses high pressure and temperature to kill unwanted microorganisms)
  • sterilising the inoculating loop before use by passing it though a Bunsen flame
  • liquid bacterial cultures should be kept in a vial with a lid (which can be briefly opened when transferring the bacteria)
  • after transferring the bacteria, the lid of the petri dish should be lightly taped on to prevent microbes from the air entering the dish
48
Q

how can we calculate the area of the zone of inhibition around a paper disc

A

use the same formula to find the area of a circle which is:
pi * radius^2

49
Q

list some reasons as to why commonly prescribed antibiotics are becoming less effective

A
  • not taking them for the full course
  • over use of antibiotics
  • use of antibiotics in farming
50
Q

not taking them for the full course

A

if a patient doesn’t take antibiotics for the full course, then there may still be some bacteria left in the body, which can mutate and become antibiotic resistant
this resistant bacteria can then spread between organisms

51
Q

overuse of antibiotics

A

ill patients often expect a prescription of antibiotics but if patients have viral infections, such as the common cold and not a bacterial one, the antibiotics are ineffective and unnecessary

52
Q

use of antibiotics in farming

A

used to keep animals well, help them grow, and prevent disease
could lead to antibiotic resistance spreading from animals to human hosts

53
Q

ways to reduce antibiotic resistance

A
  • using them for the correct amount of time
  • treating different bacterial infections with specific antibiotics
  • patients suffering with an antibiotic resistance bacteria should be put in isolation
  • high hospital hygiene should be maintained (e.g. doctors should wash their hands every time they see a patient)

Biology Topic 5 - health (3 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions