Bacteria on Roast Beef

• Green blobs are Salmonella bacteria

• Probably got on beef on the feet of a house fly

• If it is left in a warm place, the bacteria will multiply

• If you then ate it, the thousands of bacteria could make you very illX 2000X 2000

Think…….Pair….

…..Share!

My ideasMy ideas

My partner’s ideas

The class’s ideas

But HOW does bacteria make us feel ill?

Key Words

Pathogen, Virus, Bacteria, Microorganism, Semmelveis, Infection, Immunity, Toxins

Why do we get ill?

Year 10

Success Criteria

You have achieved a Grade C if you can:

1.Define the term ‘pathogen’ and describe how bacteria and viruses differ from other organisms

You have achieved a Grade B if you can:

2. Explain how pathogens cause disease

3. Describe the contribution made by Semmelweiss to the control of the spread of infection in hospitals

You have achieved a Grade A/A* if you can:4. Do all of the above, plus explain why Semmelweiss’ ideas were not immediately accepted.

What I need of you today:

1. I need you all to listen to me, and to each other in

complete silence, and paying full attention.

2. I need you to always work to the absolute best of

your ability.

3. I need you to work as a team, safely, sensibly

and effectively.

Watch the video and answer the video questions

How did you do?

Microorganisms

• Living things that are too small for

us to see without a microscope –

they include bacteria and viruses.

• Visible organisms are made up of

many cells. But each bacterium is

made of just one cell – You could

fit 1000 of them into 1mm

• Viruses are even smaller – you

could pack 1000 of these inside a

single bacterium

Microorganisms and Disease• Microorganisms that cause

infectious diseases are called

pathogens

• When bacteria enter the body, they

reproduce rapidly. They may produce

waste products called ‘toxins’ that

make you feel bad. The toxins get

carried around in your blood so even

if the bacteria are only in one place in

your body you feel feel the effects all

over your body. Key Words:Pathogens, Microorganisms, Toxins

• A virus will actually get inside one of your cells and reproduce there.

• When lots have been produces they will burst out of the cell destroying it. The viruses then invade other cells.

Quick Questions

1. What does pathogen mean?

2. How do bacteria make you feel ill?

3. How do viruses damage the body?

4. Arrange these in order, smallest first:

human cell, virus, bacterium

Key Words:Pathogens, Microorganisms, Toxins, Invade, Damage,

Success CriteriaY10

You have achieved a Grade C if you can:

1.Define the term ‘pathogen’ and describe how bacteria and viruses differ from other organisms

You have achieved a Grade B if you can:

2. Explain how pathogens cause disease

3. Describe the contribution made by Semmelweiss to the control of the spread of infection in hospitals

You have achieved a Grade A/A* if you can:4. Do all of the above, plus explain why Semmelweiss’ ideas were not immediately accepted.

When one person in your family has a cold, you all end up getting it! Why?

Stand up please.Now shake hands with everyone in the

room. It’s only polite.Now take a look at your hands, what can

you see?

Ignaz Semmelweis

• A Hungarian doctor who worked in 2 labour wards in Austria in the 1840’s

• The wards were only cleaned once a month. Doctors didn’t wash their hands and often wore filthy coats

• He was horrified at the number of women who died after easy births – with very high temps – puerperal fever – no one had any idea of what caused the disease.

• Semmelweis noted that 3 times the number of women were dying in teaching ward compared to midwives ward

• He tried to find out what the wards were doing differently, but was unsuccessful.

• Then a professor was cut with knife that had been used on woman who dies from fever – the professor himself developed fever and died

• Semmelweis thought there must have been something on the knife that had caused the disease

• He made all doctors wash their hands in chlorine water before examining the women and the death rate plummeted

• He published his findings, but noone believed him!• This was partly due to the fact that bacteria were

yet to be properly discovered and linked with disease.

Draw a flow chart to show the development of Semmelweis’ discovery

What did he make the doctors do?What did he make the doctors do?

What did he observe? What happened to make him think?

What did he observe? What happened to make him think?

What horrified him?What horrified him?

What were the results?What were the results?

Who was he? Where was he working?

Now lets see how clean your hands are!

• In pairs place a piece of sellotape on the back of each of your hands and then lay it onto the agar

• Gently remove the sellotape from the agar and put the lid back on the plate

• Mark your plate with your initials and date and then seal the plate with two pieces of tape in a cross

• Place your plate back in trap for incubation.

The Semmelveiss Handwash Technique

• Used by healthcare workers all over the world.

Assessment

• Answer the questions provided

Success CriteriaY10

You have achieved a Grade C if you can:

1.Define the term ‘pathogen’ and describe how bacteria and viruses differ from other organisms

You have achieved a Grade B if you can:

2. Explain how pathogens cause disease

3. Describe the contribution made by Semmelweiss to the control of the spread of infection in hospitals

You have achieved a Grade A/A* if you can:4. Do all of the above, plus explain why Semmelweiss’ ideas were not immediately accepted.