prokaryotic cells and viruses Flashcards
why are bacteria cells so successful
much of their success is a result of their small size, normally ranging from 0.1 to 10um in length
describe the cell wall of a bacteria cell
a cell wall, which is made up of murein. this is a polymer of polysaccharides and peptides.
many bacteria further protect themselves by secreting a capsule of mucilaginous slime around this wall
what is inside the cell wall
the cell surface membrane
within it is a cytoplasm that contains 70S ribosomes- these ribosomes are smaller than those in the cytoplasm of a eukaryotic cell.
how does bacteria store food reserves
glycogen granules and oil droplets.
how is genetic information stored in prokaryotic cells
circular strands of DNA
seperate from this are peices of DNA, called plasmids.
what can plasmids do
they can reproduce themselves
give the bacterium resistance to harmful chemicals, such as antibiotics
what else are plasmids used as
vectors in genetic engineering
comparison of prokaryotic and Eukaryotic cells
prokaryotic- DNA in the form of plasmids
Eukaryotic- No plasmids, DNA is linear
prokaryotic- no membrane-bound organelles
Eukaryotic- membrane-bound organelles such as mitochondria
prokaryotic- ribosomes are smaller 70S
Eukaryotic- ribosomes are larger 80S
prokaryotic- cell wall made of murein
Eukaryotic- cell wall made of cellulose
role of cell wall in prokaryotic cell
the cell wall supports the cell and prevents it from changing shape
its made of a polymer called murein
murein is a glycoprotein ( a protein with a carbohydrate attached)
role of capsule in bacterial cell
protects the bacterium from other cells and helps groups of bacteria to stick together for further protection
role of the cell membrane in a bacterium
role of a capsule in a prokaryotic cell
some prokaryote capsules are made up of secreted slime.
it helps to protect bacteria from attack by cells of the immune system
role of the plasmids in a prokaryotic cell
plasmids are small loops of DNA that aren’t part of the main circular DNA molecule.
Plasmids contain genes for things like antibiotic resistance and can be passed between prokaryotes.
Plasmids are not always present in prokaryotic cells.
some prokaryotic cells have several
