1.KS3 Biology8C Microbesand Disease1 of 31 20 Boardworks Ltd 20042005

2. Contents 8C Microbes and Disease What are microbes? Uses of microbes How microbes cause disease Fighting disease Summary activities1 of 31220 Boardworks Ltd 2004 2005 3. What are microbes?Microbes are very smallliving things and aresometimes calledmicro-organisms.Microbes are so tiny that theycannot be seen with thenaked eye. They can only beseen using a microscope.How many different microbescan you name?1 of 31320 Boardworks Ltd 20042005 4. Different types of microbesThere are three types of microbes: microbesbacteria viruses fungi1 of 31420 Boardworks Ltd 2004 2005 5. Bacteria fact fileBacteria e.g. Salmonella and Streptococcussize: 1/1000 mmshape: Bacteria can be spherical,rod-shaped or comma-shaped.structure: Bacteria are single-celled organisms, which do notcompletely have a nucleus.Some cause disease, but manyare useful.reproduction: Bacteria reproducevery quickly. Two can very quicklybecome four, then eight and so on.1 of 31520 Boardworks Ltd 20042005 6. Bacterium structure1 of 31620 Boardworks Ltd 2004 2005 7. Viruses fact fileViruses e.g. flu virus and HIV (the AIDS virus)size: 1/1,000,000 mmshape: Viruses have regularand geometric shapes.structure: A virus is a simpleorganism which does notdisplay ALL the characteristicsof living things. They are madeup of a protein coating andsome genetic material.reproduction: Viruses can onlygrow and reproduce within otherliving things.1 of 31720 Boardworks Ltd 2004 2005 8. Virus structure1 of 31820 Boardworks Ltd 2004 2005 9. Fungi fact fileFungi e.g. Penicillium and yeastsize: Some fungi can actuallybe seen with the naked eye,others are slightly bigger thanbacterial cells.shape: Fungi come in manydifferent shapes.structure: Fungi have themost complex structures ofall the microbes. They feedoff other living things.1 of 31920 Boardworks Ltd 20042005 10. Fungi (yeast) structure1 of 2010 of 31 Boardworks Ltd 20042005 11. Contents8C Microbes and DiseaseWhat are microbes?Uses of microbesHow microbes cause diseaseFighting diseaseSummary activities1 of 2011 of 31 Boardworks Ltd 20042005 12. Using microbes bacteria and fungi Microbes have many uses that are based on the fact that microbes can be grown. Bacteria grow in milk to make it go off. This type of bacterial growth is used to make milk into yoghurt. Cheese is another product that is made from milk. Fungi can also be used to make food. The meat substitute Quorn is a protein produced using fungi.1 of 2012 of 31 Boardworks Ltd 2004 2005 13. Using microbes yeast Yeast is a type of fungus and carries out respiration. The respiration of this microbe can be used in different ways in baking bread and in brewing. The aerobic respiration of yeast is used to make bread rise. Yeast uses the sugar in bread dough to carry out aerobic respiration:glucose carbon oxygen dioxide waterenergy What gas produced by the aerobic respiration of yeast causes bread to rise?1 of 2013 of 31 Boardworks Ltd 20042005 14. Using microbes yeast The anaerobic respiration of yeast is used to make beer and wine. In this case, the yeast respires without oxygen and produces alcohol (ethanol). This process is known as fermentation. Yeast converts the sugar into alcohol by anaerobic respiration:glucosecarbon dioxideethanol energy How do brewers make sure that yeast respire without oxygen?1 of 2014 of 31 Boardworks Ltd 2004 2005 15. Contents8C Microbes and DiseaseWhat are microbes?Uses of microbesHow microbes cause diseaseFighting diseaseSummary activities1 of 2015 of 31 Boardworks Ltd 20042005 16. Microbes can cause disease The diseases caused by microbes and their severity depend on the type of microbe. viruses bacteria fungiinfluenza (flu) food poisoningfungal sinusitis mumpssore throats athletes foot chickenpoxtuberculosis Onychomycosis (TB) (causes discoloured smallpoxtetanus toe nails) poliocholerarabiestyphoid German measleswhooping coughviral bacterial meningitismeningitis1 of 2016 of 31 Boardworks Ltd 2004 2005 17. Which type of microbe?1 of 2017 of 31 Boardworks Ltd 2004 2005 18. How do microbes enter the body? Microbes can enter the body in many different places. eyesearsmouth nose skincuts genitals How are the diseases caused by microbes spread?1 of 2018 of 31 Boardworks Ltd 2004 2005 19. How are microbes spread? The spreading of microbes and disease is known as transmission. 1. Transmission by air A cough or a sneeze can release millions of microbes into the air which can then infect somebody else. 2. Transmission by water Dirty water can transmit many diseases, e.g. cholera, which can be transmitted by drinking.1 of 2019 of 31 Boardworks Ltd 20042005 20. How are microbes spread? 3. Transmission by animals An animal can carry a microbe from one place to another, e.g. a mosquito which spreads the malaria parasite. 4. Transmission by contact Many microbes can be exchanged from one person to another by direct or indirect contact: direct contact by hand; indirect contact, e.g. by walking on a wet floor already contaminated by someone else who has athletes foot; sexual contact.1 of 2020 of 31 Boardworks Ltd 2004 2005 21. How are microbes spread? 4. Transmission by contact There are other forms of indirect contact, e.g. the transmission of microbes from mother to unborn child. Transmission through the placenta If the mother develops the HIV/Aids infection, it can be passed on to the unborn child through the placenta. Transmission via breastfeeding If a child is being breastfed, he or she can also pick up microbes from the mother via the mothers milk.1 of 2021 of 31 Boardworks Ltd 2004 2005 22. How is the spread of disease stopped? The spread of disease can be prevented by making sure that good hygiene is used in key places such as bathrooms and kitchens. Chemicals called antibiotics can be used to treat bacterial infections.People can be immunized againstsome diseases by the injection of avaccine.1 of 2022 of 31 Boardworks Ltd 2004 2005 23. Contents8C Microbes and DiseaseWhat are microbes?Uses of microbesHow microbes cause diseaseFighting diseaseSummary activities1 of 2023 of 31 Boardworks Ltd 20042005 24. Fighting microbes How does the body fight off microbes that cause disease?1 of 2024 of 31 Boardworks Ltd 20042005 25. What do white blood cells do? The human body has a number of natural defences against microbes. Noses are hairy inside to trap microbes! white blood cell The body also produces white blood cells to help defend it from microbes. Some white blood cells can destroy microbes antigen by engulfing them.antibody Some white blood cells are able to produce chemicals called antibodies. These pairing with matching antigens on the surfaces of microbes and so help the white blood cells to engulf microbes.1 of 2025 of 31 Boardworks Ltd 2004 2005 26. White blood cell engulfs microbe animation1 of 2026 of 31 Boardworks Ltd 2004 2005 27. White blood cell and antibodies animation1 of 2027 of 31 Boardworks Ltd 20042005 28. Contents8C Microbes and DiseaseWhat are microbes?Uses of microbesHow microbes cause diseaseFighting diseaseSummary activities1 of 2028 of 31 Boardworks Ltd 20042005 29. Glossary antibiotics Chemicals prescribed as medicine to killbacteria inside the body. antibodies Chemicals produced by white blood cellsto fight microbes that cause disease. bacteria The type of microbes that are single-celledorganisms. fungi The type of microbes that feed off other livingthings. immune Resistance to infection caused by a microbe. microbe A very small living thing. transmission The spread of a disease from person toperson. viruses The type of microbes that can only grow andreproduce within other living things.1 of 2029 of 31 Boardworks Ltd 20042005 30. Anagrams1 of 2030 of 31 Boardworks Ltd 2004 2005 31. Multiple-choice quiz1 of 2031 of 31 Boardworks Ltd 2004 2005