Chapter 4 Flashcards
procaryotic cells are only found in which two domains?
archaea and eubacteria
Do prokaryotic cells contain organelles and a nucleus?
no
What are the essential structures of a cell?
cell wall, membrane, cytoplasm, ribosomes, and chromosomes (DNA)
What are some specific structures found in some but not all cells?
flagella, pili, fimbrae, capsules,slime layers, inclusions, actin skeleton, and endospores
What are flagella and axial used for?
motility function
What are the functions for fimbrae and pili?
for attachment and channel function
Which bacteria has has an unusual case of having amphitrichous and lophotrichous flagellar arrangement?
Aquaspirillum
What are axial filaments?
internal flagella enclosed on the space between the cell wall and the cell membrane
Where are axial filaments found?
spirochetes
What are chemotaxis bacteria?
bacteria move in response to chemical signals
What is a pilus?
long and thin tubular appendages made of tublar protein
What are fimbriae?
bristle like fibers emerging from the surface of many bacterial cells
What two bacteria are not infectious when they lack fimbraie?
Neisseria and E. coli
What is a cell envelope?
complex layers external to the cell protoplasm
What are the layers of the cell envelope?
cell membrane, cell wall, and glycalix
What develops as a surface coating of macromolecules to protect the cell?
glycocalix
Glycocalix is responsible for the colonization in what medical devices?
plastic catheters, intrauterine devices and metal pacemakers
What are two types of glycocalix?
slime layer and capsule
How does a slime layer protect a cell?
protects against dehydration and loss of nutrients
What is the structure of a slime layer?
lose structure, easy to remove or wash off
What is the structure of a capsule layer?
thick and gummy layer, difficult to remove
How does a capsule protect a cell?
protects against phagocytes, providing greater pathogenecity
What are cell walls made of?
made of a molecule called peptidoglycan