Introduction to Bacteria Flashcards
Do bacteria have a nucleus
No
What are the cell surface features of Gram positive bacteria
Plasma membrane
Periplasmic space
Peptidoglycan
They stain purple using Gram staining
What are the cell surface features of Gram negative bacteria
Plasma membrane
Periplasmic space
Peptidoglycan
Outer membrane (consisting of lipopolysaccharide and protein)
They stain red/pink using Gram staining.
What cell surface features to Gram positive and Gram negative bacteria share
Plasma membrane
Periplasmic space Peptidoglycan
What shape do cocci have
Spherical
What shape do bacilli have
Rod
What are the main structures of a typical bacterial cell
Chromosome Cytoplasm Cell wall Ribosome Penicillin binding proteins Peptidoglycan Lipopolysaccharide Capsule Flagella Fimbriae Plasmid Bacteriophage Spores
What is the function of a capsule
Rigid capsule - protects bacteria from being engulfed
Fragile capsules - form strong biofilms and enables them to engulf cells
What types of flagellum are there
A-Monotrichous (e.g. Vibrio Cholerae) - has 1 flagellum
B-Lophotrichous (e.g. Sprillium spp) - has multiple flagella from a singular point
C-Amphitrichous (e.g. Rhodospirillum rubrum) - has flagellum on both sides
D-Peritrichous - has flagella all over (e.g. Escherichia coli).
What is the function of flagellum
Motility
What is the function of fimbriae
Adherence
How do bacteria replicate
Binary fission - creates identical bacterium
How do bacteria create genetic variation
Spontaneous mutation
Transfer of DNA
How can individual bacteria be seen
Using a microscope with a x1000 oil immersion lens and staining (e.g. Gram, fluorescent dyes)
How can bacterial colonies be seen
Through cluture on a solid medium (e.g. agar) then by eye
