Pasteur's Experiment - role of microbes (1 Viewer)

[04er]

in the dot point it says:

perform an investigation to model Pasteur's experiment to identify the role of microbes in decay

Okay, so microbes are needed for the broth to decay. Is there a way to say that more technically?

 

[04er]

Also, if someone could please turn to page 79 in the Biology Macquarie Revision Guide, why did broth decay in the second conical flask? (for those that dont have the book, they drew three diagrams. One has the conical flask open to the air so that obviously the broth decays. IN the second diagram, a conical flask containing broth with an attached stopper and glass tube bent into an S-shape has been boiled.... and the broth decayed :S. In the third diagram, it is the same as the second, just that the S-shaped glass tube has been slightly filled with water, and only the broth in this flask did not decay.) Help please! It's different in Heinemann, with their explanation, i would expect the S-shape to be enough for spores in the air to be trapped and not enter the flask (didn't think water was necessary)

 

[babydoll_]

"The presence of microbes is required for the decay of the broth. The microbes are present in this flask as there is no inhibition to their entry." Sounds nice?

Tis probably an error. Technically, spores should get caught in the bends of the S-tube, preventing microbial growth. I don't have Macq Guide though so I can't give a proper answer, sorry.

 

[04er]

"The presence of microbes is required for the decay of the broth. The microbes are present in this flask as there is no inhibition to their entry." Sounds nice?

so is that the 'role of microbes'? Because thats the part I'm most uncertain about.

 

[nesstar]

yeah...i can't think of a more sophisticated way of putting it...basically decay occurs only when there are microbes present.

and that macquarie guide must be wrong...the flask with the s-shaped should have a pristine broth...we gained this result in the prac we did at school also

 

[babydoll_]

so is that the 'role of microbes'? Because thats the part I'm most uncertain about.

'Role' sounds a bit odd. Basically microbes cause decay. No microbes = no decay