Prokaryotic cells Flashcards
What does a prokaryotic cell have?
-Pilli
-Flagella
-70s ribosomes
-Nuceloid
-Cell membrane
-Mesosomes
-Plasmids
-Cell wall
-Photosynthetic membranes
-Capsid/slime layer
What features do not all prokaryotic cells have?
-Flagella
-Plasmids
-Photosynthetic membranes
-Capsid/slime layer
What does pilli mean?
-Thread like protein projections found on the surface of some bacteria
-It is used to attach to the host cells for sexual reproduction
What is a nuceloid?
An area in a bacterium where we find a single length of coiled DNA
What are mesosomes?
-Either in foldings of the cell membrane in bacteria
-Could be human error when observing the cell
What is a photosynthetic membrane?
Produces glucose
What does the capsid do?
The protein coat of a bacteria which prevents the cell drying out and hides the fact that the cell is foreign
What are the features of prokaryotic cells?
-Smaller cells
-Always unicellular
-No nucleus, no membrane bound organelles
-Circular DNA
-Smaller ribosomes (70s)
-No cytoskelenton
-Cell wall containing peptoglycan
How do antibiotics affect bacteria cells?
-Some antibiotics target cell walls, some target 70s ribosomes
-Some inhibit the formation of the peptoglycan layer in the cell wall (this affects gram positive bacteria but doesn’t affect gram negative bacteria because their cell wall is hidden and less vital to their structure)
How do polypeptide antibiotics work?
They affect gram negative bacteria because it interacts with the phosopholipids on the outer membrane (this wouldn’t affect gram positive bacteria)
-Rarely used due to the severe side effects
How do most antibiotics work?
Target common processes e.g protein synthesis
What are viruses?
Intracellular parasites which can only exist and reproduce in the cells of other living organisms
-they all have similar shapes and structures but vary in genetic material
-viruses are classified depending on their type of genetic material and their mode of replication
-they are acellular (non-living)
What is a capsomer?
A repeating protein unit making up the capsid
What do viruses use their receptors and tails for?
To attach to host cells
What does the envelope do?
Prevents the body detecting that the virus is foreign
-not present in all viruses