3.6: Prokaryotic cells and viruses Flashcards
Difference between prokaryotic and eukaryotic
Pro are smaller and simpler
pro have genetic material not enclosed in a nucleus
Flagella (plural)
Long hair-like structure that rotates to move the cell
Not all prokaryotes have a flagellum/some have more than 1
DNA in prokaryotes
circular DNA
one coiled up strand
floats free in the cytoplasm not enclosed in a nucleus
Plasmids
Small loops of DNA separate from the circular DNA molecule, which contain genes that can be passed around prokaryotes eg: antibiotic resistance
Capsule
secreted slime around cell which helps to protect bacteria from attack by immune system cells
Acellular
not cells
Viruses are made of
a nucleic acid surrounded by protein
Viruses vs bacteria
viruses are smaller
no plasma membrane
no cytoplasm
no ribosomes
Host cells
Normal cells that are invaded by viruses which reproduce inside them
Viruses genetic material
DNA or RNA in a core
with a capsid (protein coat) around the core
How viruses attach to host cells
attachment proteins on the capsid stick out and will cling to a host cells
How do prokaryotes replicate
binary fission
Binary fission
The cell replicates, making copies of its genetic material
then splits into 2 daughter cells
Different viruses have different
attachment proteins
(therefore requires different receptor proteins on host cells
-not all viruses can infect all cells)
Viruses aren’t
alive