prokaryotic cells and viruse

Example prokaryotic cell

bacteria

Compare Eukaryotic and Prokaryotic cells

Eukaryotic cells	Prokaryotic cells
have nucleus	don’t have nucleus
larger than prokaryotic cells	smaller than eukaryotic cells
dna in nucleus (chromsomes) have nuclear envelope, nuclear pore, nucleoplasm, nucleolus + chromosomes	single circular DNA molecule free in cytoplasm and not protein bound
have membrane bound organelles and ribosomes	cytoplasm lacks membrane bound organnelles
ribosomes, mitochondria, golgi apparatus, chloroplast, nucleus endoplasmic reticulum	ribosomes
80s ribosomes	70s ribosomes
cell wall plants and algae=cellulose cell wall fungi=chitin	cell wall made of murein aka peptidoglycan (glycoprotein)
don’t have plasmids, capsule and flagella	can have plasmids, capsule and more than 1 flagella

What are plasmids

small loops of additional DNA which only carry a fw genes eg antibiotic resistance genes (if the bacteria as one)

not present in all prokaryotic cells

What is capsule

slimy layer made of protein

prevents bacteria from desiccating (drying out) and protect bacteria against host immune system (prevent phagocytosis)

not present in all prokaryotic cells

What is flagella/ flagellum

tail like structure that rotates to allow prokaryotic cell to move

not present in all prokaryotic cells

Viruses are…

acellular non living and parasitic (rely on a host cell to replicate)

structure of viruses

• nucleic acid (DNA or RNA) (can be single stranded or double stranded)

• enclosed in a protein coat called capsid

• some viruses have outer layer called lipid envelope (from the host cell membrane)

• + attachment proteins on surface of capsid or envelope (outermost surface) to allow virus attach to specific receptors on host cells

Process prokaryotic cells divide

binary fission

Describe binary fission

Replication of circular DNA

Replication of plasmids

Division of cytoplasm to produce daughter cells (2)

features of all prokaryotic cells that r not featured in eukaryotic cells

Murein/ peptidoglycan cell wall

DNA not associated with proteins (histones)

DNA free in cytoplasm

Asses why the APs (type of polypeptide that can make protein channel) do nit damage eukaryotic cells of organism that produce them but damage prokaryotic cells

Because eukaryotic cells have cholesterol whereas prokaryotic cells do not

Cholesterol stabilises membranes and restricts movement of molecules/phospholipids making up membrane

So APs cannot enter and distrupt the eukaryotic membrane

Describe differences between structure of DNA in prokaryotic cell and eukaryotic cell

Prokaryotic dna has no introns/ not associated with proteins (histones)/ circular not linear