prokaryotes + viruses Flashcards
define eukaryotes
cells with distinctive features such as a nucleus, mitochondria + chloroplasts
define prokaryote
much smaller cells with distinctive organelles
circular dna floating in cytoplasm
give the 2 sub-sections of prokaryotes
archaebacteria (ancient bacteria)
eubacteria(modern bacteria)
define viruses
tiny
always parasitic
not made of cells
can only reproduce inside of living cells
do prokaryotes or eukaryotes have smaller ribosomes
prokaryotes
what kind of organelles do eukaryotes have
membrane-bound organelles
what is the flagellum for in eukaryotes
movemnent
what are prokaryotic cell walls made of
murein
what are plasmids
dna
what does dna look like in prokaryotic cells
naked circular dna
plasmids
what are pili for in prokaryotic cells
for attachment
what is binary fission
replication of bacteria
what are the mark points of binary fission
- replication of circular dna
-replication of plasmids
-division of cytoplasm (cytokinesis)
forming 2 daughter cells
define pathogen
an organism that has teh ability to cause disease
what does acellular mean
not a cell
viruses
what are viruses missing that living cells have
cytoplasm
cell membrane
cant reproduce on its own (needs a host cell)
what form of genetic information can viruses have
DNA or RNA
what are viruses with rna called
retroviruses
what is an example of a retrovirus (virus with rna)
HIV
what does HIV stand for
human immunodeficiency virus
what enzyme does HIV have and what does it do
reverse transcriptase
reverses transcription
what are hiv immunoproteins made of and what are they used for
made of glycoproteins
they are put into vaccines to help people develop resistance to the virus as the body would recognise the foren cells and takes action agains cells quicker
what are the features of hiv
or all viruses
attachment proteins
capsid
RNA/DNA
lipid envelope
how do viruses reproduce mps
virus attachment proteins bind to cell membrane
virus empties DNA/RNA into cells nucleus
cell start making attachment protein and capsids
how does reverse transcription using transcriptase work
dna integrates into nucleus
premature virus is developed
premature virus takes cell membrane with lipid envelope familiar to immune system with it
hiv drug blocks attachment proteins stopping them from binding with lymphocytes
what do prokaryotic cells have that eukaryotic cells dont
no-membrane bound organelles
smaller ribosomes
cell wall with murein
plasmids
capsule
flagella(s)
what do eukaryotic cells have that prokaryotic cells dont
nucleus
membrane bound organelles
larger ribosomes
describe viruses
acellular
non-living
describe the structure of viruses
genetic material (DNA/RNA)
capsid
attachment proteins
after binary fission ,how many circular rings of dna and plasmids are there
1 circular dna
a variable number of copies of plasmids
do viruses undergo cell division and why
no because they are non-living
who replicates virus
following injection of nucleic acid, the infected cell host replicates the8 virus particles