Bacteria Flashcards
What genetic material is found inside a bacterium?
Single chromosome
No nucleus
What colour will Gram positive and gram negative bacteria show, when stained?
Positive = Purple
Negative = Red
What are the differences in the structure of Gram positive and negative bacteria?
Positive - thick peptidoglycan (murein) wall
Negative - thin peptidoglycan (murein) wall + outer membrane
What is the outer membrane made of, in gram negative bacteria?
Lipopolysaccharides + proteins
In a bacterial cell, what separates the inner membrane from the peptidoglycan wall?
Periplasmic space
What shape does ‘cocci’ signify?
Spherical
What shape does ‘bacilli’ mean?
Rod shaped
What purpose does the murein / peptidoglycan wall serve?
Strength and shape
What protein molecules are present on the surface of bacteria, that are involved with forming cross links?
Penicillin binding proteins
What surface feature gives bacteria motility?
Flagellum
What surface feature is used by bacteria to attach to cells?
Fimbriae
What is the purpose of capsules?
Prevents the bacterium from being engulfed by phagocytes
What does monotrichous mean?
Single flagellum on bacterial cell
What does Peritrichous mean?
Flagella all over the cell
What does Amphitrichous mean?
Flagella on both sides of the bacterium
What does Lophotrichous mean?
Tuft of flagella from one place on bacterium
What is the basic purpose of spores?
Contains protected ‘version’ of bacterium + nutrients which can grow later
What are plasmids?
Circular loops of DNA
Not in the chromosome
Plasmids can be transferred from one bacterial cell to another. What structure allows this to take place?
Pillus
In terms of plasmid transfer, what is a promiscuous bacterium?
One that can pass a plasmid to either a gram positive or gram negative bacterial cell
What is the name given to the gene transfer using pillus’s and plasmids?
Conjugation
How do bacterial cells replicate?
Binary fission
What are the 3 ways that bacteria transfer DNA?
Conjugation
Transformation
Transduction
What is transformation?
When a bacteria is surrounded by DNA, it takes up some of the DNA hat contains advantageous genes
Bacteriophages attach to bacterium using what two features?
End plate
Tail fibres
Describe the structure of a bacteriophage.
Head Collar ]Tail End plate Tail fibres
(+genetic info etc)
What two things make up the names of strains of bacteria?
Genus and species
