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GCSE Core Science Human Biology Key Words ANTIBIOTIC, PENCILLIN, PAINKILLER, NATURAL SELECTION, PANDEMIC, EPIDEMIC, MUTATION GCSE Core Science Objectives Human Biology By the end of the lesson I will: •Know that antibiotics can be used to kill bacteria inside your body •Know that it is very difficult to kill viruses because they reproduce inside the bodies cells (so destroying the virus means destroying the cell!) •Know that painkillers can relieve the symptoms of a disease • Know that it is difficult to control a pathogen that changes through mutation (occurs in an instant) or natural selection (occurs over time and is a gradual process) •Know that bacteria DO NOT have a ‘brain’ so they do not ‘want’ to develop a resistance to antibiotics they just do! •Know what MRSA is and why it is a concern. (Multiple resistant Staphylococci Aureus) •Be able to read graphs GCSE Core Science Starter Human Biology I know HOW TO USE ASEPTIC TECHNIQUE GCSE Core Science How do we effect change? Human Biology We are going to grow some yeast….. AND THEN KILL IT! 1. Using ASEPTIC TECHNIQUE infect a petri dish with a yeast solution. WHAT DID YOUonto the centre of the agar Place a full drop of antiseptic plate. FIND OUT? 2. Wait for the solution to slightly dry (perhaps 1hour) 3. 4. Incubate for 24-48hours. WHAT ARE YOU TRYING TO FIND OUT? WHAT DO YOU EXPECT TO FIND OUT? GCSE Core Science Human Biology GCSE Core Science Alexander Fleming Human Biology Alexander Fleming is attributed to discovering penicillin in his lab. One day after a holiday he returned to his untidy lab to find a ring in the agar around a mould. He tried unsuccessfully to extract the juice (the penicillin). 10 years later he finally gave up and another scientist pair ‘Ernest Chain and Howard Florey’ discovered a way to extract and produce the drug in industrial amounts. This was first used in the second world war and still is used today GCSE Core Science How do they work? Human Biology Antibiotics work by damaging the bacterial cell wall without harming your cells. What is a mutation? A mutation is caused when you get ill, you take an antibiotic and most of the bacteria is killed except for a few who survive as they are resistant to the antibiotic. Since there are only a few remaining, the body is able to remove these or ingest them. GCSE Core Science What is natural selection? Human Biology When you are ill you are given a antibiotic to kill the bacteria. To prevent there arestart to The antibiotic kills most this of thetrend bacteria and you feel well and takingthat the medication. This leaves a twostop things we can do; number of bacterial cells that are resistant to the antibiotic. These resistant bacteria reproduce and you get 1. Only take antibiotics for sick again. bacterial infections You get given a different stronger antibiotic 2. Take the full course of which kills most of the bacteria and you start to feel well and stop antibiotics that have been taking the medication. This leaves a number of bacterial prescribed cells that are even more resistant and you fall ill again. GCSE Core Science Human Biology Antibiotic resistance Antibiotics have been used to control bacterial diseases for some time. Erythromycin was first available in the UK in 1954 to control infections, caused by Staphylococcus bacteria, in young babies. GCSE Core Science Antibiotic resistance Human Biology The graph shows the development of Erythromycin resistance in bacteria. GCSE Core Science Antibiotic resistance 1 What important event took place in the bacterial population sometime during 1956? Human Biology GCSE Core Science Human Biology Antibiotic resistance Answer to question 1 1) Erythromycin resistance started to develop in Staphylococcus as a result of a mutation. GCSE Core Science Antibiotic resistance Human Biology 2 What decision did Hospital E and Hospital W take concerning the use of Erythromycin in 1959 and 1961 respectively? GCSE Core Science Human Biology Antibiotic resistance Answer to question 2 2) Hospital E stopped using Erythromycin in favour of an alternative antibiotic in 1959. Hospital W stopped using Erythromycin in favour of an alternative antibiotic in 1961. GCSE Core Science Antibiotic resistance Human Biology 3 What effect did the action taken in 1959 and 1961 have on the percentage of organisms resistant to Erythromycin? GCSE Core Science Human Biology Antibiotic resistance Answer to question 3 3)In the case of Hospital E, the percentage of Erythromycin-resistant Staphylococcus fell straight away. In Hospital W, it fell after a delay of more than one year. GCSE Core Science Antibiotic resistance Human Biology 4 If resistance is inherited and the decision to withdraw Erythromycin use had not been taken, what long-term change in the Staphylococcus population would take place? GCSE Core Science Human Biology Antibiotic resistance Answer to question 4 4)Eventually all the Staphylococcus would be resistant to Erythromycin. Antibiotic resistance by natural selection GCSE Core Science Human Biology Bacteria – a few will have mutations that make them resistant to antibiotics Antibiotic 1 given – only those bacteria that are resistant survive to breed Antibiotic 2 given – only those bacteria that are resistant survive to breed Now bacteria are resistant to two antibiotics GCSE Core Science Extension Human Biology Use page 69 to answer this A* question What problems do mutations cause in modern hospitals? What Principles can we use to affect change? 5 marks GCSE Core Science Objectives Human Biology By the end of the lesson I will: •Know that antibiotics can be used to kill bacteria inside your body •Know that it is very difficult to kill viruses because they reproduce inside the bodies cells (so destroying the virus means destroying the cell!) •Know that painkillers can relieve the symptoms of a disease • Know that it is difficult to control a pathogen that changes through mutation (occurs in an instant) or natural selection (occurs over time and is a gradual process) •Know that bacteria DO NOT have a ‘brain’ so they do not ‘want’ to develop a resistance to antibiotics they just do! •Know what MRSA is and why it is a concern. (Multiple resistant Staphylococci Aureus) •Be able to read graphs