B1 - Infections and Response Flashcards
Antibiotics
Medicines that help to cure bacterial disease by killing infective
bacteria inside the body.
Clinical drug testing:
Drug testing done on healthy human volunteers and
patients.
Double blind trial:
A study performed where neither the researcher or patient
know whether the patient is taking the drug or a placebo.
Gonorrhoea
A sexually transmitted disease (STD) caused by a bacterium with
symptoms of a thick yellow or green discharge from the vagina or penis and pain
on urinating.✢
Human Immunodeficiency Virus (HIV):
An infectious virus that weakens the
immune system and can lead to AIDS (acquired immunodeficiency syndrome).
Measles
A serious disease caused by a virus that shows symptoms of fever and
a red skin rash.
*Monoclonal antibodies:
: Antibodies produced from a single clone of cells
that are specific to one binding site on one protein antigen
Non-specific defence
General physical and chemical barriers that defend the
body against lots of different types of pathogen.
Pathogens:
: Microorganisms that cause infectious disease
Placebo
A substance designed to be indistinguishable from a drug being tested
but has no actual effect on the patient.
Preclinical drug testing:
Drug testing done in a laboratory using cells, tissues
and live animals.
Rose black spot:
A fungal disease where purple or black spots develop on
leaves, which often turn yellow and drop early.
Salmonella:
A bacterial disease that is spread by bacteria ingested in food and
can cause a fever, abdominal cramps, vomiting and diarrhoea.
Tobacco Mosaic Virus (TMV):
A widespread plant pathogen affecting many
species of plants which produces a mosaic pattern on the leaves and limits the
plant growth.
Vaccination:
The process of introducing small quantities of dead or inactive
forms of a pathogen into the body to stimulate the white blood cells to produce
antibodies.✢
White blood cell:
An important type of cell that makes up the immune system and
produces antibodies and antitoxins.
how do aphids cause damage to plants
they use their sharp mouthparts to extract sap from the plant phloem, weakening the plant. They are also vectors who can transfer pathogens from diseased plants to healthy plants
how can we reduce the number of aphids
1) chemical pesticides
2) biological pest control - lady birds
why do plants need a good supply of nitrate ions
nitrate ions are required to convert sugars into proteins which are required for the plant to grow .
why do plants need a good supply of magnesium ions
magnesium ions are required to synthesise chlorophyll, which absorbs light energy during photosynthesis .As a result , the leaves cannot photosynthesise properly and turn yellow
what are the symptoms of disease in plants
stunted growth (lack of nitrate ions) , spotted leaves, decaying , discolouration
what are 2 ways in which plant disease can be identified
1) reference to a gardening website
2) laboratory testing
give examples of physical defence responses used by plants
1) cellulose cell walls
2) tough waxy cuticle on leaves
3)outside layer on stems on trees
4)leaf fall
give examples of chemical defence responses used by plants
1) antibacterial chemicals
2) poisons
give example of mechanical defence responses use by plants
1) thorns and hairs to deter animals
2)leaves that curl on contact
what is a pathogen
a disease- causing microorganism e.g. bacteria
how do bacteria cause disease
once inside the body, they divide rapidly by binary fission. They kill cells and produce harmful toxins
how do viruses cause disease
they invade and reproduce inside living body cells , leading to cell damage
give 3 ways in which pathogens can be spread
1) by air - flu , tuberculosis and the common cold are spread by droplet infection
2) by water - fungal spores in water spread plant diseases
3) by direct contact - common in plant diseases and sexually transmitted infections
give 4 ways in which the spread of pathogens can be reduces
1) hygiene - handwashing
2)reducing contact with infected individuals - quarantine
3) removing vectors - using pesticides
4) vaccination
what is measles
measles is a serious viral disease that can cause blindness and brain damage. The main symptoms are a fever and a red skin rah
how is measles spread
by air - through inhalation of droplets from coughs and sneezes
what is HIV/AIDS
HIV is a virus which attacks and damages the immune system until it can no longer function properly. AIDS is the condition resulting from a long-term HIV infection. There is no cure for this .
How is HIV spread
Direct sexual contact and the exchange of bodily fluids eg. blood, breastmilk
how can the spread of HIV/AIDS be prevented
1) use of condoms
2)not sharing needles
3)screening of blood for transfusions
4)bottle - feeding
what is tobacco mosaic virus
A plant pathogen which causes leaf discolouration when cells are damaged. Affected areas cannot photosynthesise. As there is no treatment farmers grow TMV - resistant crop strains to avoid infection
how is tobacco mosaic virus spread
contact between infected and healthy plants. Insects may act as vectors which transfer the virus between different plants
what is salmonella
a type of bacteria found in raw meat, poultry and eggs. If they enter the body via food poisoning ,they can affect natural gut bacteria
what are the symptoms of salmonella food poisoning
fever , abdominal cramping , vomiting , diarrhoea
how can the spread of salmonella be limited
1) vaccinating animals
2)thoroughly cook meat
3) disinfect hands and surfaces after contact with raw meat
what is gonorrhea
a sexually transmitted bacterial infection caused by unprotected sex with an infected individual. Early symptoms include yellow/green discharge from genitals and painful urination , although it may be symptomless
1) its spread can be controlled with antibiotics
what is rose black spot
a fungal disease which causes purple or black spots to develop on rose leaves .It reduces the area of the leaf which is available for photosynthesis and causes leaves to turn yellow and drop prematurely.
how is the rose black spot fungus spread
fungal spores are spread by the wind and in water
how can the rose black spot fungus be treated
1) using fungicides
2) destroying infected leaves
what is malaria
Malaria is the disease cause by protist pathogens. The disease is carried from the host to host by mosquitoes and the protists enter the human bloodstream when they feed. Symptoms include fever and shaking
how can the spread of malaria be reduced
1) using insecticides
2) using insect nets
3)antimalarial drugs
how does the skin prevent pathogens from entering the body
1) acts as a physical barrier
2) scab formation after skin is cut
how does the respiratory system prevent pathogens from entering your body
1) nose -has hairs and mucus which traps pathogens
2) trachea and bronchi - has mucus that traps pathogens. Ciliated cells move mucus to the mouth so it can be swallowed
how does the stomach prevent pathogens infecting the body
secrets hydrochloric acid - kills any pathogens present
how does phagocytosis protect us against disease
white blood cells (phagocytes) ingest and destroy pathogens so they cannot infect more cells
how does antibody production protect us against diesease
white blood cells produce antibodies which are complementary to a specific antigen on a pathogen. The binding of antibodies to antigens cause pathogens to clump together , making them easier to destroy . In the case of a second infection , the correct antibodies can be produced rapidly , preventing the person getting the same disease again
how does antitoxin production protect us against disease
antitoxin bind to toxins released by pathogens and neutralise them
what is a vaccination
contains a dead or inactivated form of pathogen which stimulates white blood cells to produce complementary antibodies to the pathogen. In the case of a second infection , memory cells can rapidly produce the correct antibodies and prevent illness
what are the advantages of vaccinations
1) they have eradicated deadly diseases eg. smallpox
2)many epidemics can be prevented by vaccinations
what are the disadvantages of vacccinations
1)not guaranteed to work
2) may be side effects
what drugs are used to cure some bacterial disease
antibiotics - they can kill bacterial pathogens inside the body
how do antibiotics work
antibiotics eg. penicillin kill bacterial pathogens inside the body , but do not kill human cells .
why can antibiotics not be used to treat viral dieases
antibiotics have no effect on viral pathogens as they live inside the hosts (human ) cells .
what is antibiotic resistance
antibiotic resistance occurs when mutations lead to individual bacteria being resistant to an antibiotic. These bacteria are able to survive , reproduce and pass on their alleles , leading to a greater population of antibiotic - resistant bacteria
how can we prevent antibiotic resistance
1) avoid overuse and unnecessary use
2) finish antibiotic courses - to ensure all bacteria is killed
what effect do painkillers have on infectious diseases
painkillers can only treat the symptoms but do not kill pathogens
what plant is the heart drug digitalis extracted from
foxgloves
what painkiller originates from a compound found in willow bark
aspirin
what antibiotic was discovered by alexander Fleming from a type of mould
penicillin
what are the 4 qualities of a good medicine
effective , safe , stable , able to be taken in and removed easily
what 3 main factors are tested for when developing a new drug
toxicity , efficacy , dose
how is preclinical testing carried out
in a laboratory - uses cells , tissues and live animals
how is clinical testing carried out
uses healthy volunteers and patients . Firstly the drug is testes at a low does on healthy people - then tested on patients and on a larger scale to find the optimum dose .Often , one group receive a placebo (not the test drug ) and he other group receive he actual drug in order to assess its efficacy
