2. Investigating Pop Growth Of Bacteria

Question 1

What do bacteria need to grow at steady state?

Answer 1

Food

Space

Question 2

How can we investigate population growth of bacteria ?

Answer 2

Growing bacteria in liquid broth - containing nutrients the bacteria needs to grow

Called broth culture - if it contains lots of bacteria it will appear cloudy

Question 3

What happens when light is passes through a sample of broth culture ?

Answer 3

Some of it is scattered because bacteria is present - testing amount of light passing through culture

Question 4

Spectrophotometer

Answer 4

Measures the amount of light passing through a sample of culture and produces an absorbance value

And can also output a clue of the % of light transmitted

More bacteria in culture the less light will pass through to be detected by spectrometer which will produce higher absorbance

Question 5

Broth culture with high absorbance =

Answer 5

High number of bacteria present o