I - Generalities Flashcards
Cells: DNA within a nuclear membrane
Eukaryotes
Cells: Uses mitotic division
Eukaryotes
Cells: DNA associated with histones
Eukaryotes
Cells: Has more than one chromosome
Eukaryotes
Cells: Has membrane-bound organelles
Eukaryotes
Eukaryotes: Ribosomes
40s + 60s = 80s
Cells: DNA within a nucleiod
Prokaryotes
Cells: Uses binary fission
Prokaryotes
Cells: Has only one chromosome
Prokaryotes
Prokaryotes: Ribosomes
30s + 50s = 70s
Cell Walls: Plants & Algae
cellulose
Cell Walls: Fungi
chitin
Cell Walls: Diatoms
silica
Cell Walls: Prokaryotes
peptidoglycan
Cell Walls: Archaea
pseudopeptidoglycan
Cell Walls: Protozoa & Animals
none
An ancestral eukaryotic cell is thought to have engulfed the bacterial ancestor of
mitochondria
An early eukaryotic cell, already possessing mitochondria, engulfed a photosynthetic bacterium and retained it in symbiosis resulting in
chloroplasts
Microorganisms: Has cells
bacteria, fungi, protozoa & helminths
Microorganisms: 0.02-0.2 μm
viruses
Microorganisms: 1-5 μm
bacteria
Microorganisms: 3-10 μm
fungi (yeasts)
Microorganisms: 15-25 μm
protozoa & helminths (trophozoites)
Microorganisms: Has either DNA or RNA
viruses
Microorganisms: Has both DNA & RNA
bacteria, fungi, protozoa & helminths
Microorganisms: Has no nucleus
viruses
Microorganisms: Has prokaryotic nucleoid
bacteria
Microorganisms: Has eukaryotic nucleus
fungi, protozoa & helminths
Microorganisms: Has no ribosomes
viruses
Microorganisms: Has 70s ribosomes
bacteria
Microorganisms: Has 80s ribosomes
fungi, protozoa & helminths
Microorganisms: Doesn’t have mitochondria
viruses, bacteria
Microorganisms: Has mitochondria
fungi, protozoa & helminths
Microorganisms: Has a protein capsid and lipoprotein envelope
viruses
Microorganisms: Has a rigid wall with peptidoglycans
bacteria
Microorganisms: Has a rigid wall with chitin
fungi
Microorganisms: Has a flexible membrane
protozoa & helminths
Microorganisms: Motile
some bacteria, most protozoa & helminths
Microorganisms: Replicates via Binary Fission
bacteria
Microorganisms: Replicates via Budding or Mitosis
fungi
Microorganisms: Replicates via Mitosis alone
protozoa & helminths
Obligate intracellular but acellular parasites of plants, naked RNA, no human diseases
viroids
Mobile genetic elements
Transposons
DNA pieces that move readily from one site to another either within or between the DNA of bacteria, plasmids and bacteriophages
“jumping genes” (transposons)
DNA replication followed by insertion of a new copy into another site
Replicative Transposition
DNA is excised from the site without replicating and then inserts into the new site
Direct Transposition
Prions: Normal form of protein encoded by the host’s chromosomal DNA, suceptible to protease and soluble in detergent
PrPc
Prions: Abnormal isoform of PrPc which modifies folding of normal prion-like proteins found in the body and has a high beta-sheet content
PrPres / PrPsc
Appearance of vacuolated neurons with loss of function and lack of immune response or inflammation
Spongiform Encephalopathies
Human Prion Diseases
Creuzfeld-Jakob (CJD, cortical), Kuru (“k/guria” - to shake, cerebellar), Variant CJD (vCJD), Gerstmann-Straussler-Scheinker (GSS), Fatal Familial Insomnia (FFI), Sporadic Fatal Insomnia (SFI)
Animal Prion Diseases
Scrapie (sheep/goat), Transmissible Mink Encephalopathy, Bovine Spongiform Encephalopathy (Mad Cow), Chronic Wasting Disease (mule/deer/elk)
Prions are _____ to standard viral disinfection procedures and have very long incubation periods as long as ____.
impervious, 30 years
Prions: Transmission
infected tissue, cuts in skin, transplantation of contaminated tissue (cornea), contaminated medical devices (brain electrodes), ingestion of infected tissue (cannibalism), inherited
Prions: Susceptible Populations
women and children of the Fore tribe in New Guinea, neurosurgeons, neurosurgery patients, transplant surgeons, transplant patients