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56 Cards in this Set
- Front
- Back
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what are the main food groups? |
carbs, fats and proteins |
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why are carbs needed? |
a source of energy for life processes |
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why are fats needed? |
1. source of energy 2. make cell membranes 3. insulate our bodies |
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why are proteins needed? |
1.growth and repair 2.building cells |
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what is respiration? |
a chemical reaction that allows cells to take energy from food |
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what is the metabolic rate? |
the speed at which chemical reactions take place in the body |
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what factors affect the metabolic rate? |
1. age 2. gender 3. inherited factors |
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what is metabolic rate affected by? |
1. proportion of muscle to fat in the body 2. amount of physical activity |
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where is cholesterol made? |
the liver |
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why is cholesterol needed? |
for healthy cell membranes |
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To much cholesterol in the blood can increase the risk of... |
1. heart disease 2. diseased artiers |
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what are pathogens and what are the chemicals they contain? |
microorganisms that cause disease. Anitgens. |
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what are the main types of pathogens? |
1. bacteria 2. viruses |
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how do bacteria work? |
once inside the body they release poisons/toxins that make us feel ill |
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what are some diseases caused by bacteria? |
1. food poisoning 2. cholera 3. typhoid 4. whooping cough |
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what is the structure of a virus? |
fragment of genetic material inside a protective protein coat |
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where can viruses only reproduce? |
inside host cells (they damage the cell when they do this) |
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how do viruses work? |
when inside a cell it makes it makes thousands of copies of itself. the copies fill the host cell and burst it open. viruses then passed into bloodstream, the airways and other routes. |
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what are some diseases cause by viruses? |
1. flu 2. colds 3. measles 4. mumps 5. rubella 6. chicken pox 7. AIDS |
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what three things can white blood cells do? |
1. ingest pathogens and destroy them 2. produce antibodies- destroy particular pathogens 3. produce antitoxins - counteract the toxins realised by pathogens |
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what are antibodies and antitoxins? |
specialised proteins |
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what white blood cells can produce specific antibodies to kill a particular pathogen? |
lymphocytes |
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what two ways can antibodies neutralise pathogens? |
1. bind to pathogens and damage/destroy them 2. coat pathogens so they clump together making them easy to ingest by white blood cells called phagocytes |
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what does each lymphocyte produce? |
a specific type of antibody (a protein that has a chemical fit to a certain antigen) |
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what happens when a lymphocyte with the right antibody meets the antigen? |
the lymphocyte reproduces quickly making many copies of the antibody to kill the pathogen |
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what do vaccination cause the body to produce? |
enough white blood cells to protect itself against a pathogen |
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why do we need vaccinations? |
people can be immunised against a pathogen that are resistant to antibiotics. |
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are all vaccines the same? |
no, different ones needed for different pathogens |
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what is the MMR vaccine used for? |
to protect children against measles, mumps and rubella |
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what happens during a vaccination? |
a small amount of an inactive form of pathogen is put into the body |
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what three things can vaccines contain? what do they all act as? |
1. live pathogens treated to make them harmless 2. harmless fragments of the pathogen 3. dead pathogens ALL ACT AS ANTIGENS |
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what do vaccines do when injected into the body? |
stimulate white blood cells to produce antibodies against the pathogen |
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what happens if the person gets infected by the pathogen later? |
their body can respond in the same way as if they had the disease before |
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what did Ignaz Semmelweiss do? |
realised the importance of cleanliness in hospitals |
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what did he insist on and was it effective. |
- doctors washing their hans - yes |
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why was his ideas ignored at the time? |
people did not know that dieases were caused by pathogens that could be killed |
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what do painkillers do? |
relieve the symptoms of an infectious disease. |
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what are three types of painkillers? |
1. paracetamol 2. aspirin 3. morphine |
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how do paracetamol, aspirin and morphine work? |
they block nerve impulses from the painful part of the body. |
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what do antibiotics? |
substances that kill bacteria or stop their growth |
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why don't antibiotics work against viruses? |
as viruses live and reproduce inside cells. DIFFICULT TO DEVELOP DRUGS THAT KILL VIRUSES WITHOUT DAMAGING THE CELLS |
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what was the the first antibiotic? who? when? |
- penicillin - alexander fleming - 1928 |
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how did alexander fleming discover penicillin? |
he noticed that some bacteria he left in a petri dish had been killed by some naturally occurring penicillin |
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do all antibiotics work in the same way? |
no, specific bacteria should be treated using specific antibiotics |
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why can some bacterial strains become resistance to antibiotics? |
natural selection ( in large populations of bacteria may be some cells that are not affected by the antibiotic. these survive and reproduce making even more bacteria that are not affected by the antibiotic) |
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what is MRSA? |
a strain of bacterium that is resistant to most antibiotics |
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to slow down/stop growth of resistant strains of bacterium what 2 things should we do? |
1. avoid unnecessary use of antibiotics 2. complete the full course of antibiotics |
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what does the appearance of resistant strains of bacteria mean? |
that vaccination and antibiotics may no longer work (new antibiotics must be developed as a result) |
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what are the main steps in the development of resistance? |
1. antibiotics kill pathogens of non-resistant strain 2. resistant strain survive and reproduce 3. population of resistant strain increases |
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how can the development of resistant strains of bacteria be slowed down? |
avoid using antibiotics for infections that are not serious e.g. mild throat infections |
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who discovered how to grow bacteria in a petri dish? when? |
- robert koch - 1878 |
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what was Robert lock able to discover? |
which bacteria caused certain diseases e.g. TB and cholera |
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what are cultures of microorganisms? |
micro-organisms that have been grown for a purpose |
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what are cultures of microorganisms used for? |
to investigate the action of antibiotics and disinfectants |
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what is used so cultures stay uncontaminated? |
sterile conditions - everything sterilised - lid of petri dish sealed by sticky tape to stop microorganisms from the air getting in |
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what is the maximum temp used in schools and college labs? |
25 degrees, warmer temp might allow growth of pathogens to a dangerous amount |
