topic 3 infection and response

dec-

salmonella food poisoning

type of pathogen

symptoms

how to treat individual

how to prevent spread of pathogen

• bacteria

• fever, stomach cramps, vomiting/nausia, diarrhoea, dehydrated

• let bacteria + toxins pass through digestive system

• wash hands after toilet/sick, cook chicken properly, vaccinate chickens, store chicken in fridge, dont wash chicken

Gonorrhoea

type of pathogen

symptoms

how to treat individual

how to prevent spread of pathogen

• bacteria

• green/ yellow discharge from penis/vagina, pain when urinating

• take antibiotics

• use a condom during sexual intercourse

measles

type of pathogen

symptoms

how to treat individual

how to prevent spread of pathogen

• virus

• rred skin rash, fever

• control fever and reduce pain (with pain killers)

• cover nose/mouth when sneezing, bin tissues immediatly

HIV and AIDS

type of pathogen

symptoms

how to treat individual

how to prevent spread of pathogen

• virus

• flu-like symptoms initialy, may be without symptoms for years, white blood cells are killed so more prone to cancers and infections

• take antiretrovirals

• use a condom, dont share needles

Tobacco mosaic virus

type of pathogen

symptoms

how to treat individual

how to prevent spread of pathogen

• virus

• mosaic pattern where leaves became yellow and discoloured, therefore plants cant photosynthesis as well so less/ stunted growth

• no cure - isolate and destroy infected plant

• isolate infected plant from uninfected plants

rose black spot

type of pathogen

symptoms

how to treat individual

how to prevent spread of pathogen

• fungus

• purple/black spots on leaves, leaves can turn yellow and drop off so less photosynthesis and plant doesnt grow as well

• use fungiside, strip plant of affected leaves and destroy them

• strip plant of infected leaves and destroy them so fungus cant spread

Malaria

type of pathogen

symptoms

how to treat individual

how to prevent spread of pathogen

• protist (mosquitos are vectors)

• repeated episodes of fever, can be fatal

• reduce fever

• use insect repellent to reduce mosquito bites, sleep under mosquito net

why arent viruses not considered cells

they rely on a host cell to make more copies as a virus can only reproduces with a host cell. If a virus is left long enough without a host cell it will die

how do virues spread further

they invade a cell, replicate using host cell and burst out

what dont viruses have(5)

nucleus

mitochondria

cell membrane

cytoplasm

ribosone

what do viruses have (3)

genetic material

protien coat

antigens

pathogen define

a microorganisms tha can cause diseaeses

how can pathpgens be spread (3)

water

air

direct contact

how has the bidy defended its self from diseases

eyes

produces tears which is contain a natural antiseptic

how has the bidy defended its self from diseases

hair + mucus in the nose

trap particles that could contain pathogens so it doesnt enter further into the airway

how has the bidy defended its self from diseases

stomach

produces hydrochloric acid which kills pathogens that make it that far from the mouth

how has the bidy defended its self from diseases

blood

platelets seal open cuts and wounds

how has the bidy defended its self from diseases

mucus and ciliated cells lining the trachea and bronchi

mucus traps pathogens which in turn are wafted back up the throat by ciliated cells where it can be swallowed

how has the bidy defended its self from diseases

skin

forms a barrier to pathogens and secretes antimicrobial substances which kill pathogens

phagocytosis define

a cellular process where white blood cells (phagocytes) engulf foreign cells and digests them to kill these pathogens

process of phagocytosis (5)

1. a bacteria releases toxins (which make us feel unwell)

2. a phagocyte recognices the bacteria and moves towards it

3. the phagocyte engulfs the vacteria

4. the phagocytes enzymes digests the bacteria

5. the digested materials are absorbed or released out of the phagocyte and the bacteria is killed

whaqts a lymphocyte

a type of white blood cell that makes antibodies and aqntitoxins

the shape of the toxin and the anti toxin are …. to each other

how does this help

complementary

this helps them to neutralise the toxin

flow diagram for someone being ill by a bacteria causing a disease

1. a lymphocyte detects the bacteria and makes antibodies

2. the lymphocyte reproduces which means more antibodies are being made which bind to the antigens of the bacteria

3. the bactera, now tagged with antibodies are found by phagocytes which engulfs the bacteria, digests it anf kills it.

4. after the bacteria are killed, most of the lymphocytes making the antibodies die, but some stay in the blood (called memory cells)

   someone is infected by the same bacteria

5. the memory cells that make the right shaped antibody are already in their blood. They make antibodies quickly and in high concentrations

6. angtibodies made by memory cells bind to the pathpgen, which engulfs the bacteria, digests it and kills it

7. the bvacteria are killed before they can make them ill again

whats the difference between the primary and secondary response for vaccinations (3)

primary responce

-lower concentration of antibodies made

-antibodies made slower

-concentration of antibodies decrease rapidly after peak

secondary response

-higher concentrayion of antibodies made

-antibodies made quicker

-concentration of antibodies decrease slowly after peak

flow chart of pathpgen being killed when a person has been vaccinated (5)

1. a dead/weakened pathogen is injected into an indivisuals blood stream

2. white blood cells produce specific antibodies against the dead/weakened pathogen

3. antibodies bind to the dead/weakend pathogen and kill it

   the vaccinated indibvidual encounters the same pathogen again

4. memory cells in the blood immediatly recognise the pathogen and make a higher concentration of specific antibodies quickly

5. antibodies bind to the pathogen and kill it

pros and cons of vaccinations (4,2)

pros

-less chance of being infected by diseases

eradication of serious diseases on society

big out breaks of diseases (epidermics) are prevented if majoity population is vaccinated

vaccines are cheaper than treating ill people

cons

-vaccines dont always work/ give you immunity

-small chance of harmful side effects

area of a circle

πr²

flow chart of culturing microorganisms + why (8)

1. bacteria are grown on a culture medium (e.g agar jelly) - this contains carbs (glucose), minerals and proteins the bacteria needs to grow

2. petri dishes and agar gel must be sterilised before use - to kill any bacteria that are present in the solution or on the petri dishes

3. disinfectants are used to wipe the work area and equipment before starting the practical - to sterilise the work equipment to prevent bacteria from the air and the work surface from contaminating the petri dish

4. the spreader used to transfer the bacteria ontothe petri dish is heated in a budsen burner flame - this sterelises the spreader

5. the lid of the petri dish is only lifted when bactera is being transferred and is only lifted slightly - prevents unwanted bacteria in the air from contaminating the petri dish plate

6. wen the lid is closed, it is secured by 2 small pieces of tape - prevents unwanted bacteria in the air from contaminating the petri dish plate

7. only 2 pieces of tape are used to secure the lid onto the petri dish, not all around the petri dish - this would stop oxygen reaching the bacterium and this may encourage the growth of harmful anaerobic bacteria

8. incubate the petri dish at maximum temp of 25°C - this still allows bacteria to grow but reduces the chance of growing harmful bacteria

organ transplant define

when a donar gives their organ to a patient whose organ is no longer working properly

when does a patients immune system reject their donated organ and why

if the type of tissue type in the recipient and donor don’t match. The patients immune system will recognise the donated organ as foreign and so white blood cells make antibodies which bind to antigens on the cells of the donated organ, killimg the cells

how to prevent organ rejection

-a donor organ with a tissue type similar to the patients is used

-patient ia treated with immune suppresant drugs to suppress the immune system

antigen define

the protein molecule on the surface of pathogens that identify as it as a pathogens

antibodies define

what lymphocytes make and release into the blood stream

4 types of medicine and what they treat

• painkillers - reliefs pain

• antivirals - viruses

• antifungles - fungle infections

• antibiotics - kills bacteria

painkillers treat symptoms not pathogens

what makes a good drug (3)

• effective - cure, diseases

• safe - not toxic, unwant side effects

• successfully taken in and removed from your bodyand works where its supposed to

aspirin

use

organism that chemical in drug originates from

painkiller that lowers fevers

willow tree

digitalis

use

organism that chemical in drug originates from

treats heart conditions

foxgloves

penicillin

use

organism that chemical in drug originates from

an antibiotic used to kill bacteria and treat bacterial infections

mould

what do you want to test for in drug trials (4)

-efficiancy

-toxicity and safety

-any side effects

-optimum dosage

flow chart of how they test drug trials

• computer modelling - carried out on 1000 drugs to choose 1 or 2 drugs that are suitable to test for

• preclinical trials - drug is tested on live cells/mice

• clinical trials - phase 1 - drug tested on small number of healthy volunteers, done at a low dose to monitor safety and side affects

• clinical trials - phase 2 - drug tested on small number of ill volunteers, done at a low dose to monitor safety and side affects

• clinical trials - phase 3 - drug tested on a large does of ill volunteers. done to find the optimum dosage and to test for efficiency

• peer review of data - other scientists peer review the results of the drug trial to check the validity of the data and to help prevent false clames

• drug is approved if it passes alkl stages above

when were antibiotics discovered

1928

problems with antibiotic (3)

what can this lead to

-over use

-failing to complete the fully prescribed course by a doctor

-use of antibiotics in farming

can lead to antibiotics becoming less effective and increase in antibiotic resistance (known as superbugs)

why is over use a reason antibiotics are becoming less effective

people feel unwell and when going to the doctors, they expect to be prescribed antibiotics. If the patient has a viral infection (e.g common cold) instead of bacterial antibiotics are ineffective and unnecessary

why is failing to complete the course a reason antibiotics are becoming less effective

-patients should always complete the prescribed course of antibiotiocs so all bacteria is killed and none survive - so no bacteria mutate and produce resistant strains

-patients usually feel better after 10 days of taking the medicine - therefore stop taking them. This is harmful as random mutations can occur leading to antibiotic resistance (occasionally)

why is agricultural use a reason antibiotics are becoming less effective

Previously antibiotics were regularly used in farming and these can be used to…

-prvent diseases

-keep anumals well+ allow them to grow quickly

the high use of antibiotiic resistance from anumals into human hosts. Legal controls are now in place to try reduce the antibiotics this way

ways to reduce antibiotic resistance

-only take antibiotics when necessary

-treat specific bacteria with specific antibodies

-high hospital hygene leveks - including regular hand washung by staff visitors

-patients who are infected with antyibiootic resistant strains should be isolated from other patients

what might happen in the future that peoiple are concerned about with antibiotics

some bacteria will be resistance to all knon antibiotics

why did the development of new antibiotics stop years ago

as they were hailed as the solution to a very different disease problem. Some limited succsess with the new antibiotic research has occured recently

antibiotic define

substance that controls the spread of bacteria in the body by killing them or stopping them reproducing

antibiotic resistance define

the ability of bacteria to survive exposure to survive exposure to antibiotics. Caused by mutations in their genes

mutations define

random, spotanius change in the structure of a gene, chro,osone or number of chromosomes

how does antibiotic-resistant bacteria develop

1. bacteria show variation because some bacteria have mutations in their DNA

2. first day of antibiotics - the antibiotics kill the bacteria that are not resistant to

3. more non-resistant bacteria are killed when the patient keeps taking antibiotics

4. the patient starts to feel better and stops taking the antibiotics

5. the bacteria that are resistant to antibiotics reproduce and many more antibiotic-resistant bacteria are made. The patient feels ill again

how are monoclonal antibodies made

1. a mouse is injected/vaccinated with a specific antigen

2. lymphocytes in the mouses blood make antibodies that are complementary to the specific antigens

3. these lymphocytes are extracted from the mouses spleen

4. the lymphocyte is fused with a tumor cell to make a hybridoma cell. A tumor cell is used as it divides rapidily by mitosis

5. the hybridoma cell is cloned to produce many genetically identical cells that all divide quickly and produce the same desired antibodies

6. a large amount of the antibodies is collected and purified

how are monoclonal antibodies are used to treat cancer

1. anti cancer drug is attached to the monoclonal antibody

2. this is injected into the body

3. the monoclonal antibody binds to the antigens (tumour markers) on the tumour cells. They bind becuase the shapes are complementary

4. the drug is delivered to cancer cells only and the drug kills these cells

5. side affects of the drug are minimised because the drug was not delivered to normal body cells. This is becuase the monoclonal antibody doesnt bind to the antigen on normal body cells becuase their shapes are not complementary

how monoclonal antibodies are used in research

1. a fluoresent dye is attached to the monoclonal antibody

2. this is added to a sample. If the molecule/antigen that you want to study is present in the sample youre analysing, the monoclonal antibodies will to them becuase they are complementary in shape

3. the location of antigens is indicated by the flouresent green light

pros and cons of using monoclonal antibodies (5,7)

pros

• are specific - their use can be targeted as they are complementary to the shape of specific antigens - therefore fewer side effects

• when traeting diseases they provide a rapid treatment

• used to identify pregnancy, diagnose diseases + identify substances

• saved many lives, treated many diseases, diabetioes

• monoclonal antibodies are quicker to develop than other treatments e.g vaccines

cons

• radiation + chemotherapy can result in hair loss, suppressed immune system + reduction to clot blood

• production of tumor cells involves inducing cancer in mice

• the production of monoclonal. antibodies takes time

• only a limited supply can be produced

• expensive to produce

• some deaths - associated with the treatmemt of sclerosis (hardening body tissue)

• side effects - fever, vomiting, low blood pressure

are the monoclonal antibodies found in this poart of the pregnancy test free or fixed and what do they bind do

1. reaction zone - free - hCG hormone

2. test zone - fixed - hCG hormone

3. control zone - fixed - the free antibody with the blue bead from the reaction zone

how are monoclonal antibodies used in pregnancy tests

1. female wees on sample pad - if shes pregnant her urine will contain a hormone called hCG

2. reaction zone - hCG binds to a mobile monoclonal antibody (with a blue dye attached to them that are specific to hCG (complementary)) in gthe reaction zone. The hCG in a pregnant womans urine will bind to the monoclonal antibodies in the reaction zone

3. The test zone contains a fixed monoclonal antibodies that are specific to hCG hormone as well. If a woman is pregnant the hCG that is already bound to monoclonal antibodies from the reaction zone will also bind to the fixed monoclonal antibody in the test zone (they bind as they are complementary in shape so hCG is sandwhiched between two MA)

4. control zone contains fixed monoclonal antibodies specific to to the free monoclonal antibodies from the reaction zone. Regardless of wether the woman is pregenat the fixed monoclonal antibodies in gthe control zone will bind to the free monoclonal antibodies from the reaction zone as theya are complemenatry in shape

5. if the woman is pregenat 2 lines show up - 1 at the test zone and another at control zone. If the woman isnt pregnant only 1 kline shows up at the control zone

   the coloured line is due to the presence of the dye/ hCG attached to the free MA

whats the purpose of the control zone (2)

ensure the test works and to preventy false positives

signs of plant disease (6)

• abnormal growths

• stunted growth

• patches of decay/ rot

• discolouration

• spots on leaves

• malformed stems/ leaves

how are plsnt pathogens spread (4)

1. direct transmission - from plant to plant

2. animakl vectors - e.g other pathogens spread by beetles, humans ect

3. indirect transmission - e.g via soil, wind, machinery, compsot

4. pathogens/ fungal spores- through wind/ water

how to identify the type of disease a plant has (3)

• klook up symptoms in a gardening manual website

• use test kits that identify the pathogen using monoclonal antibodies

• take infected plant to a lab whjere scientists can identify the plant

whats nitrate deficiency

what they use it for

what happens to plants with this deficiency

• use nitrate ions to make AA to make protien for growth

• plants who are defiencent will have stunted growth, wilting, not many leaves

whats nmagnesium deficiency

what they use it for

what happens to plants with this deficiency

• use magnesium ions to make chlorophyll so plant can absorb light for photosynthesis

• plants defient will have yellow leaves - called chlorosis

most plant leaves have a waxy cuticle

what type of plant defence is this

how does this give protection to plant

physicle defence

tricks other organisms so other organsism behave differently e.g stops butterflies from laying eggs so catapillers dont eat the leabves

some plants produce antibacterial chemicals

what type of plant defence is this

how does this give protection to plant

• chemical defense

• kills bacteria

some plants have leabves that droop or curl when something touches them

what type of plant defence is this

how does this give protection to plant

• mechanical defense

• prevent themselves from being eaten by knocking insects off themselves

plants afre surrounded by cell walls made from cellulouse

what type of plant defence is this

how does this give protection to plant

physcial defense

forms a physical barrier against pathogens that make it past the waxy cutuicel

some plants produce poisins

what type of plant defence is this

how does this give protection to plant

• chemical defense

• deters herbivors from eating them

some plants have thorns and hairs

what type of plant defence is this

how does this give protection to plant

mechanical defense

stops anumals from touching/ eatingb them

some plants mimic other organisms

what type of plant defence is this

how does this give protection to plant

mechinal defense

tricks other organisms so they behavde differentkly

plants have layers of dead cells around their stems

what type of plant defence is this

how does this give protection to plant

physical defence

provides a barrier to stop pathogens entering

aseptic techinque define

set of practises you do to ensure:

microorganisms beining investigated do not escape

microorganisms beinging investigatyed do not become contaminated with an unwanted microorganism

growth of unwanted microorganisms is orevented