Lecture 1 - Introductory Bacteriology Flashcards
Which is bigger; prokaryotes or eukaryotes?
Eukaryotes
Why is being a small cell advantageous?
Large surface-to-volume ratio: better nutrient exchange. Allows for quicker evolution
What is generation time?
The amount of time required for a a population to double
3 shapes of bacteria
Coccus, Rod, Spirillium
What colour is gram +
Purple
What colour is gram -
pink
Mycobacteria use what kind of staining for identification?
Acid Fast
Difference between gram +/-
Gram + have a thick cell wall (peptidoglycan) while - has small cell wall. Gram - has 2 layers, an outer and an inner which contains the periplasmic space
What is the importance of the bacterial cell wall
For structural purposes and preventing osmosis
What makes the cell wall so rigid?
The glycol backbone. Alternating G/M and the formation of peptide cross-linkage
What are the 3 components of a lipopolysaccharide
Lipid A, Core polysaccharide and O-specific polysaccharide
What is the O-antigen
Most important part of the lipopolysaccharide. It is used as a recognition site for the immune system. Bacteria will change this to avoid recognition.
Where is the periplasm space located?
Only in G-, between outer and inner membrane
What is a nucleoid?
Not a nucleus. Has no membrane and only contains 1 circular haploid chromosome
What is the importance of a plasmid?
These are like mini chromosomes, they replicate on their own and are NOT required by bacteria. They are simply advantageous to the bacterium. They can also be transferred to other bacteria.
