LE3 BACTERIA Flashcards
Describe binary fission.
Binary fission is the asexual division of cells. In bacteria, one bacterium can divide into 2 daughter cells in 20 minutes.
Why is agar more favourable in bacteria culturing?
Most organisms are unable to break it down.
Name the 3 ways we can characterize bacteria?
At the colony/morphology leve, the cell level, and the molecular/metabolic level.
What is a bacterial colony?
Mass of cells derived from one single isolated cells during inoculation.
What is inolculation?
The process of introducting bacteria to a growth medium.
Describe a gram positive cell.
It appears purple/blue.
It has a thick peptidoglycan cell wall.
It only has 1 membrane.
Describe a gram negative cell.
It is stained pink/red.
It has a thin peptidoglycan wall between 2 membranes.
Why would we use starch agar?
Starch agar allows us to see if a cell produces the Amylase enzyme that can breakdown the starch polysachharide into glucose (sugar) monomers.
Describe some different colony morphologies.
Rough/smooth texture, circular/filamentous/spindle shape, pigment or lack thereof.
Describe some characteristics of bacteria at a cellular level.
Is it gram +/-, how many membranes does it have, what shape is it?
Name the 3 shapes bacteria can come in.
Coccus (cocci), Bactillus (bactilli), or Spirillium (spirilia)
What different arrangements can bacterial cells have?
They can be single cells, they can be diplo (pair of 2), they can be strepto (chainlike pattern), they can be staphylo (clusters) (not applicable to bactilli)
What is amylase?
Amylase is an exoenzyme bacteria can produce in order to break down the starch polysachharide found in the red algae that our starch agar is made of.
What is selective toxicity?
Selective toxicity refers to an drug’s ability to inhibit or kill a bacteria/pathogen without significantly harming the individual taking the drug.
