Transcript pathogens - science

GCSE Core Science
Human Biology
PATHOGEN, BACTERIA,
VIRUS, TOXIN,
INFECTIOUS
GCSE Core Science
Objectives
Human Biology
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
Starter
GCSE Core Science
Human Biology
What effect
does isotonic
drinks have on
your body?
AQA
Digilist
Human Biology
B1a.3 Recovering Rates and B1a.6 High Energy Drinks
GCSE Core Science
Human Biology
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.
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.
GCSE Core Science
1. High temperature
2. Headache
3. Rash
Symptoms are produced;
•
As an affect of the toxins in your body
•
A reaction of your body to respond to the
damage/toxin
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.
2. Wait for the solution to slightly dry (perhaps 1hour)
3. Place a full drop of antiseptic onto the centre of the agar
plate.
4. Incubate for 24-48hours.
WHAT ARE YOU TRYING TO FIND OUT?
WHAT DO YOU EXPECT TO FIND OUT?
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
GCSE Core Science
Human Biology
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
GCSE Core Science
Human Biology
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
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
GCSE Core Science
Human Biology
The structure of bacteria
Cell
membrane
Cytoplasm
Genetic
material
Slime
capsule
Cell wall
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
GCSE Core Science
Types of bacteria
Human Biology
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
GCSE Core Science
Human Biology
The structure of virus
Protein coat
Genetic
material
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)
GCSE Core Science
Ignaz Semmelweiss
did nothing but complain!
Human Biology
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)
GCSE Core Science
Human Biology
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.
GCSE Core Science
Human Biology
GCSE Core Science
Objectives
Human Biology
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