structure of bacteria Flashcards
What is the general structure of bacteria?
Bacteria are unicellular prokaryote organisms, as they lack membrane bound organelles and do not have a true nucleus. Genetic material is suspended in the cytoplasm and they reproduce via binary fission
What are the three most common shapes of bacteria?
spheres, rods and spirals
What is the feature of chromosomal DNA?
It is a circular double-stranded DNA, not enclosed in a membraned nucleus, and located in the nucleoid
What is the function of chromosomal DNA?
It helps to store genetic information of the cell
What is the structure of the plasmid?
It is one of many circular double-stranded DNA, and has fewer genes than a chromosome, and can replicate independently
What is the function of the plasmid?
It helps to code for advantageous traits of the bacteria
What is the structure of the cell wall?
It is made out of peptidoglycan, and it is a rigid structure enclosing the cell membrane
What is the function of the cell wall?
It prevents cell from bursting and maintains its regular shape, and protects it from harsh conditions
What is the structure of the capsule?
It is a layer of sticky polysaccharide lying outside the cell wall, not easily removed
What is the function of the capsule?
It prevents the cell from bursting and protects it from harsh conditions, adheres to surfaces and shields pathogenic bacteria from attacks by their host
What is the structure of a flagellum?
It has a threadlike appendage
What is the function of the flagellum?
To enable to cell to move from one location to another
What is the structure of the pilli/fimbrae?
Fimbrae are usually more numerous and smaller than pilli
What is the function of the fimbrae and pilli?
They allow bacteria to stick to their substrate and to one another
