Classification, Structure and Replication of Microorgamisms Flashcards
which two species of “microorganisms” don’t count as organisms
viruses and prions
which 3 microorganisms have their own kingdoms
bacteria protista and fungi
what is the structure of a standard bacteria
nucelus has no membranę, circular and free floating
flagella for locomotion
pili and fimbriae - aid adhesion to host cells in gram negative
capsule or slime layer - polysaccharide layer to protect from phagocytosis
endospores - metabolically inert form of bacteria - protects them in times of stress
what are the 4 types of flagella
montrichous - single at back
lophotrikhous - multiple at back
amphitrichiois - one either side
peritrichious - lots all over
what is the india ink test
slime capsule absorbs it and shows up as dark
capsule excludes india ink when died
what are the categories when classifying bacteria
gram stain shape endospores atmospheric preference fastidiousness key enzymes
what is the difference between gram positive and gram negative
takes up crystal violet and turns purple (contains peptidoglycan)
negative has little peptidoglycan which counter stains pink
when classifying bacteria what does atmospheric preference mean
aerobic, anaerobic, facultative (both)
microaerophiles (prefer reduced O2)
capnophiles (prefer increased O2)
what are he 4 types of bacterial replication
binary fission
conjugation
transformation
transduction
what happens during binary fission
produce identical daughter cells
produce FtsZ ring which contracts to produce two cells
exponential process
(this process is a target for antibacterial agents)
what is doubling time
time take for one cell to split into two
what happens during conjugation
genetic variation
transfer of transposable elements such as circular plasmids - sex plus forms and plasmid is now in each daughter cells
what happens during transformation
picking up genetic material from environment - more variation - allows trasnfer of antibiotic resistance
what happens during transduction
transfer of generic information via viral vector
introduce eugenic diversity
what characteristic is shared by all fungi
eukaryotic and cell wall made of chitin
what are the two types of fungus
yeast
mould (filamentous)
what is the structure of yeasts
grow and multiple by budding - most common is thrush by C albicans
single eukaryotic, bud scar, nucleus, mitochondria, vacuole, lipid granules
what is the structure of moulds
grow in mats of tiny filaments known as hyphae that from mycelia
eg mouldy bread - penicillin spp
what can hyphae be divided into
septa
describe the process of fungal replication
asexual or sexual
asexual - non genetic diversity using spores undergoing mitosis
sexual - plasmogamy (haploid) goes to karyogamy (nuclei fuse to from diploid zygote) then undergoes meiosis (haploid spores formed) - produces unique mycelium
what are two types of parasites
protozoa - unicellular eukaryotic
helminths (animalia) - worms
what are protozoa classified by and give examples
morphology and locomotion flagellates amoebae - change shape ciliates - move due to cilia apicxomplexa or sporozoa
how do protozoa replication
asexually (fission)
but can sexually exchange information via conjugation (not with reproduction)
occurs in host, may require more than one host to complete life cycle
may from hardy cysts
what are viruses
obligate intracellular parasite (require host)
made of nucleic acid core wrapped in protein coat (some have envelope (lipid) and other are naked)
what are the steps in a virus life cycle
attachment/penetration - virus attaches via protein on its surface and enters via endocytosis
uncaring - genome released from capsid
early viral proteins produced - these allow replication and regulation
genome replication - DNA -> mRNA
late viral proteins produced - structural proteins of virus occurs in ribosomes
virion assembly - from nucelocaspid, viral proteins concentrated at caspid
what are the two types of virion release
lytic - bursts cells - kills host
lysogenic - bacteriophage, does not damage host as integrates DNA into hosts and replicates
where does replication occur for RNA viruses
primarily in the cytoplasm - non reliant on host
where does replication occur for retroviruses
uses host replication system eg HIV (integration)
how do we classify viruses
RNA (positive or negative sense) or DNA (double or singel stranded)
symmetry or dimensions of caspid
presence of an envelope
what are prions
misfiled proteins - no genetic material
can be inherited, spread or occur spontaneously
aggregate and cause misfiling of native proteins = chain reaction affecting brain
what are 3 examples of prions diseases
CJD
BSE (mad cow disease)
Scrapie - from cows and sheep
