Bacteria Flashcards
What do bacterias not have?
Single chromosome with no nucleus
What structures do bacteria have?
Capsule, flagellum, fimbriae, cytoplasmic membrane, cytoplasm, ribosomes
What is the difference between gram positive cell wall and gram negative cell wall?
Gram positive cell wall:
Plasma membrane, periplasmic space, peptidoglycan/cell wall
Gram negative cell wall:
Plasma membrane, periplasmic space, peptidoglycan, and OUTER MEMBRANE (LIPOPOLYSACCHARIDE)
How do you differentiate between gram positive and gram negative?
Use the gram stain technique.
Gram positive- purple appearance. Gram negative- red appearance.
What is the function of capsules?
Helps in preventing phagocytosis. Prevents macrophages engulfing the bacteria and killing it.
What is the function of flagella?
Provides motility to the bacterium
What is the function of fimbriae?
Provides adherence to the bacteria
What is the function of spores?
Helps bacteria survive in long periods of basification or in environmental stresses
What is the function of plasmids?
Conjugation/bridge formed between the two pili of cells, which have sex and exchange genetic material
How does bacterial replication occur?
Binary fission- identical progeny/descendance
How does genetic variation occur?
Spontaneous mutation or transfer of DNA
How do you detect and culture bacterium?
To detect bacteria- use microscopy and staining (e.g. gram staining, fluorescent dyes)
To culture- Colonies of individual bacteria on solid medium i.e. agar. Bacterial colonies can only be seen by eye.
How does bacterial nomenclature work?
Name is based on the genus and species.
What do strains of a bacterium species have?
Similar characteristics
What are DNA typing techniques used for?
To identify bacteria strains.
