PATHOGENS PATHOGEN, BACTERIA, VIRUS, TOXIN, INFECTIOUS

By the end of the lesson I: Objectives By the end of the lesson I: Know a PATHOGEN is a micro-organism that causes an infectious disease Know pathogens reproduce before they make enough toxins to make you feel ill Know what Semmelweiss discovered about the transfer of infection (Grade C) Know why it took so long for his ideas to be accepted (Grade A) Know how to use aseptic technique

What effect does isotonic drinks have on your body? Starter What effect does isotonic drinks have on your body? AQA Digilist Human Biology B1a.3 Recovering Rates and B1a.6 High Energy Drinks

How do pathogens affect your body? Infectious disease Are worldwide and range from the common cold to influenza and ebola. It is caused by a micro-organism that enters and attacks your body. People can easily transmit the pathogen from one person to the next. How do pathogens affect your body? Bacteria and virus cause disease once in your body. Bacteria split into two and produce toxins (poisons) that affect your body, sometimes directly damaging your cells. Virus rarely produce toxins. Instead they damage or destroy your cells as they take them over to reproduce.

What are common disease symptoms? High temperature Headache Rash Symptoms are produced; As an affect of the toxins in your body A reaction of your body to respond to the damage/toxin

WHAT ARE YOU TRYING TO FIND OUT? WHAT DO YOU EXPECT TO FIND OUT? I know HOW TO USE ASEPTIC TECHNIQUE How do we effect change? We are going to grow some yeast….. AND THEN KILL IT! Using ASEPTIC TECHNIQUE infect a petri dish with a yeast solution. Wait for the solution to slightly dry (perhaps 1hour) Place a full drop of antiseptic onto the centre of the agar plate. Incubate for 24-48hours. WHAT ARE YOU TRYING TO FIND OUT? WHAT DO YOU EXPECT TO FIND OUT?

Are all micro-organisms pathogens? I know a PATHOGEN is a micro-organism that causes an infectious disease and that pathogens reproduce before they make enough toxins to make you feel ill Are all micro-organisms pathogens? What is a pathogen? Photo credit: © 2006 Jupiterimages Corporation How do pathogens harm your body?

Not all bacteria cause disease but all virus' do I know a PATHOGEN is a micro-organism that causes an infectious disease and that pathogens reproduce before they make enough toxins to make you feel ill BACTERIA- single celled organisms VIRUS 50 times bigger 50 times smaller Can be seen by an ordinary light microscope Cannot be seen by an ordinary light microscope. Can be seen by an electron microscope. Reproduces by dividing in two Reproduces by taking over and using the reproductive structures of another cell. Can be killed buy antibiotics because it kills or inhibits the bacteria’s ability to divide and reproduce Cannot be killed by antibiotics Photo credit: © 2006 Jupiterimages Corporation Not all bacteria cause disease but all virus' do

The structure of bacteria I know a PATHOGEN is a micro-organism that causes an infectious disease and that pathogens reproduce before they make enough toxins to make you feel ill The structure of bacteria Cell membrane Slime capsule Cell wall Cytoplasm Photo credit: © 2006 Jupiterimages Corporation Genetic material

I know a PATHOGEN is a micro-organism that causes an infectious disease and that pathogens reproduce before they make enough toxins to make you feel ill Types of bacteria

I know a PATHOGEN is a micro-organism that causes an infectious disease and that pathogens reproduce before they make enough toxins to make you feel ill The structure of virus Protein coat Genetic material Photo credit: © 2006 Jupiterimages Corporation

did nothing but complain! I know what Semmelweiss discovered about the transfer of infection (Grade C) and why it took so long for his ideas to be accepted (Grade A) Use your text Ignaz Semmelweiss did nothing but complain! Photo credit: © 2006 Jupiterimages Corporation 5 marks

I know what Semmelweiss discovered about the transfer of infection (Grade C) and why it took so long for his ideas to be accepted (Grade A) A Semmelweiss died in 1865. B His friend Dr Jakob Kolletschka cut himself while dissecting a dead body and died of the same symptoms as ‘child bed fever’ C In hospitals where doctors took his advice, death rates from ‘child bed fever’ fell quickly. D In the 1870s Robert Koch proved that bacteria can cause disease. E Semmelweiss realised that the medical students were dissecting dead bodies on the same day they were working in the labour ward. The student midwives never dissected dead bodies. F Semmelweiss reported his findings to other doctors but he could not prove why hand washing worked because scientists knew little about bacteria and had not proved that they caused disease. G Today, Semmelweiss is widely considered to be the father of infection control. One of the main ways we prevent the spread of MRSA is proper hand washing. H In the 1840s a Hungarian doctor, Ignaz Semmelweiss, noticed that women in the labour ward staffed by medical students were much more likely to die of ‘child bed fever’ than those in the labour ward staffed by student midwives. I Semmelweiss ordered his students to wash their hands in an antiseptic solution. Unfortunately the solution damaged their skin. J In hospitals where doctors did not agree, death rates stayed high. Photo credit: © 2006 Jupiterimages Corporation

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By the end of the lesson I: Objectives By the end of the lesson I: Know a PATHOGEN is a micro-organism that causes an infectious disease Know pathogens reproduce before they make enough toxins to make you feel ill Know what Semmelweiss discovered about the transfer of infection (Grade C) Know why it took so long for his ideas to be accepted (Grade A) Know how to use aseptic technique