Microbiology 1 Flashcards
MICRO stand for?
M: microscopic I: independent C: comparatively less complex R: rapid rate of reproduction/multiplication O: omnipresent (present everywhere)
Vitamin K:
A) function
B) which microbe makes it?
C) facts? (what cause Vit K deficiency?)
Vitamin K is essential for blood coagulation
Made by large intestine BACTERIA: E Coli
facts:
newborn are given vit K shots (they dont have bacteria when they are born, unlike adults)
Vitamin K deficiency:
1) major large intestine surgery
2) long term antibiotics
3) defect in bile synthesis (vit K is fat soluble and need bile to be absorbed)
Resident microflora vs Transient microflora
Resident: permanent, through life (causes no harm in most case)
Transient: remains hours/days/months
fail to persist due to competition from others (nutrient, space), elimination from body defense cell, physical/chemical change (sweat. etc)
Division/Organization of Microbial world
living and non living:
nonliving: virus, viroids, and prions.
Living: (3 domain) bacteria, archea, and eucarya.
bacteria and archea are prokaryote (unicellular) (before nucleus, have nucleoid area instead)
Eucarya (all eukaryote) is further divided into:
a) algae (uni or multicelullar),
b) protozoa (unicellular)
(both called protist),
c) fungi (uni or multi cellular)
d) helminths (multicellular parasite)
Prokaryotic vs Eukaryotic cell
1) Prokaryote: DNA not enclose in membrane (no nucleus), have nucleoid area
Eukaryote: Nucleus present to confine DNA
2) prokaryotic have one circular chromosome, eukaryotic have multiple chromosome
3) prokaryotic have NO membranous organelle (only non membranous organelle: cytoskeleton and ribosome). Eukaryote have both membranous and non membranous organelle
4) Prokaryotic have cell wall made of peptidoglycan (primitive). Eukaryote, IF have cell wall, is simply, no peptidoglycan.
5) Prokaryote only non histone protein present, Eukaryote have both histone and non histone proteins present (associated w dna)
(Histone and nonhistone protein are two types of proteins present in the chromatin structure of DNA. They perform various functions related to DNA. )
6) Prokaryote divide via binary fission, Eukaryote divide via mitosis.
Membraous vs Non membranous Organelle
Membranous organelle:
mitochondria, golgia apparatus, endoplasmic reticulum, lysosome, nucleus, transport vesicle, vacuoles,
Nonmembraous organnlle: ribosome, cytoskeleton, centrioles, protesome.
(note: prokaryote only have non membranous organelle: ribosome and cytoskeleton)
eukaryote have everything here.
Virus:
DNA VS RNA VIRUS
EITHER DNA OR RNA (NEVER BOTH gnome, unlike us or bacterial cell which can have both)
DNA virus:
Human papillion virus (HPV), herpes virus family, small pox, HEP B,
RNA Virus:
SARS, corona virus 2, 1, polio virus, influenza virus, common cold, rabies, measle, HIV, HEP C, HEP A virus.
VIRUS is UNIQUE b/c it can contain RNA as gnome in the biological world, this is rare. (most contain dna)
How is virus transmitted?
They lack flagella, cilia, etc so NO mobility unlike bacteria.
They are PASSIVELY transmitted via air, body fluids, blood, etc.
minimal: insect bite, needles, mucosal surface
maximal: aerosole, winter, etc.
How are virus particles formed (produced)?
NO binary fission, NO mitosis. (unlike us or bacteria)
Virus particle formed by de novo assembly (fresh/ newly synthesized components) within host cell
How are virus grouped?
Into “families”; NO binomial nomenclature.
ex: rabies family, corona virus family, herpes family, etc.
PRIONS
proteinaceous, infectious, virion
protein molecule w/ infectious quality similar to viral gnome BUT NO GENETIC MATERIAL
prion protein conversion
normal; cellular form: PrPc
common in our neuron membrane)
protease sensitive, alpha helix
> > > > > > templating»>
misfold form: PrPsc (scarpie form)
protease resistant, beta helix sheet.
abnormal prions protein acts like negative influence teenager on normal prions, converting them slowly.
Dual behavior of prions, unknown amongst microbial pathogens
they are inheritable and transmissible.
Prions characteristic/structure
protein sequence identical to normal brain protein
slow incubation period (as long as 20 years) thus hard to detect
highly resistant to UV, ionizing radiation, high temp (remain active event at 90C),
not destroyed by enzymes that digest nucleic acid (DNase, RNase) (thus it is nuclease resistant)
they are inheritable and transmissible.
Why is prions infection not common, given that we have the specific protein as a membrane protein?
what is the exception?
Adjacent protein and polysaccharide in membrane lipid raft force (cholesterol enrich areas) the PrPc into correct shape (hard for it to be folded into misfolded shape) (remain in alpha helix form)
EXCEPTION:
if PrPc has methionine amino acid at 129 position, then higher risk of prion disease.
