Review 1.1 Flashcards
Yeasts
single cells
colonies in culture.
creamy, mucoid.
facultative anaerobes
molds
multicellular, filamentous.
colonies in culture
fuzzy, velvety. obligate aerobes!!
Hyphae
threadlike filaments, main mode of growth
mycelium
hyphae interweave
pseudohyphae
not true hyphae, candida has both.
fungal cell wall
contains ergosterol, target of Azoles.
14a-demethylase
synthesizes ergosterol
1-3 b-D-glucan synthase
involved in the generation of beta-glucan in fungi.
It serves as a target for antifungal drugs
Mannan
a linear polymer of the sugar mannose, cell wall polysaccharide found in yeasts.
Candida Albicans
part of normal flora
found in skin, mouth, RT, bowel, vagina
Common infections:
thrush, vaginitis, balanitis, diaper rash, esophagitis, intra-abdominal abscesses, blood stream
pathogenic fungi
coccidiodes immitis/posadasii- dimorph
candida- opportunistic
Rhizopus- opportunistic
Dimorphic fungi
geographically restricted
Mold @ 25-30 degrees
Yeast @ 35-37 degrees
Virus definition
Little (20-300nM)
cannot replicate on their own- obligate intracellular
composed of nucleic acids and proteins, can have envelope.
No organelles
Prolific replication, many progeny at a time.
Tegument
a cluster of proteins that lines the space between the envelope and nucleocapsid of all herpesviruses. The tegument generally contains proteins that aid in viral DNA replication and evasion of the immune response
capsid
Protein shell, encloses the genetic material of the virus.
Oncogenic Viruses
HPV- cervical EBV- Lymphoma, nasopharyngeal KSHV- Kaposi's, lymphoma Hep B and c- hepatocellular HTLV-1- t-cell lymphoma
p53
the guardian of genome: prevents transmission of DNA mutations.
causes cell to stop growing, or apoptose.
Mutated in disease.
Rb
Retinoblastoma protein
prevents cell cycle progression
helps control normal cell division
Bacterial Cell wall
maintains cell shape,controls influx and eflux, protects against osmotic lysis.
Site for:
Respiratory chains, secretion systems, adhesins.
contains ligands for
G+
peptidoglycan, stains purple
G-
LPS, stains pink.
how are pathogens sserotyped?
Cell wall
O antigen
outermost polysaccharide
differences between bacteria and host
single, circular chromosome
no nucleus, organelles
cell wall components
70S ribosomes
metabolism and replication