Transcript Growing Bacteria B1 1.7 modified

1. How can
we grow
bacteria?
2. Why do
we need
uncontamin
ated
cultures?
3. Why do
we incubate
bacteria at
25 degrees
celcius?
Growing and Investigating Bacteria
Starter (complete questions in book)
• What is an antibiotic?
• Why do they only target bacteria but
not viruses?
• How were antibiotics first discovered?
1. How can
we grow
bacteria?
2. Why do
we need
uncontamin
ated
cultures?
3. Why do
we incubate
bacteria at
25 degrees
celcius?
Growing and Investigating Bacteria
Key Words
• Culture medium, Agar, Antibiotics,
Mutation, Pathogen, Sterilise, Petri
dish, Innoculate.
1. How can
we grow
bacteria?
2. Why do
we need
uncontamin
ated
cultures?
3. Why do
we incubate
bacteria at
25 degrees
celcius?
Growing and Investigating Bacteria
Key Points
• An uncontaminated culture of
microorganisms can be grown using
sterilised petri dishes and agar.
• You sterilise the inoculating loop before
use and seal the dish to prevent
unwanted microorganisms getting in.
• The culture is left for 25 degrees celcius
for a few days.
1. How can
we grow
bacteria?
2. Why do
we need
uncontamin
ated
cultures?
3. Why do
we incubate
bacteria at
25 degrees
celcius?
Growing and Investigating Bacteria
Questions
• What is the agar jelly used for? (1)
• What precautions do you take to avoid
contamination? (2)
• Why is contamination an issue when
examining the effects of an antibiotic?
(2)
• Why is the petri dish incubated at 25
degrees celclius? (2)
1. What is
antibiotic
resistance?
2. Why is
mutation an
issue?
Changing Pathogens
Key Points
• Many bacterium
have developed
antibiotic
resistance due to
natural selection.
1. What is
antibiotic
resistance?
2. Why is
mutation an
issue?
Changing Pathogens
Key Points
• A mutation
results in
antibiotic
resistance, this
bacteria
survives and
replicates,
passing on the
gene.
1. What is
antibiotic
resistance?
2. Why is
mutation an
issue?
Changing Pathogens
Key Points
• If bacteria or
viruses
mutate, new
strains of the
pathogen can
appear
causing
disease.
1. What is
antibiotic
resistance?
2. Why is
mutation an
issue?
Changing Pathogens
Key Points
• Epidemic happens in one country.
• Pandemic happens in several countries.
1. What is
antibiotic
resistance?
2. Why is
mutation an
issue?
Changing Pathogens
Questions
• Describe how a bacteria becomes
resistant to antibiotics.
• Was swine Flu a pandemic or epidemic?
• Explain how swine flu killed so many
people, despite many being vaccinated
against influenza (flu).