SPHU 1020 Exam 2 Guide With
Complete Solution
Virus - ANSWER Neither eukaryote or prokaryote. Set of genes packaged in a
protein coat. May be covered by a lipid membrane derived from host cell.
Strictly intracellular. Either RNA or DNA, not both.
Bacteriophage - ANSWER Viruses that have infected bacteria
Eukaryotic Cells - ANSWER Nucleated cells, mitotic division, organelles
present, nuclear membrane present, multiple chromosomes
Fungi - ANSWER Yeast and molds, mostly free-living, eukaryotic cell
structure, but with rigid cel wall, Ergosterol in cell wall (but cholesterol in
animal cell walls)
Protozoa - ANSWER Single celled parasite. Hellminths are parasites too but
are macroscopic worms. Mostly free living. Sexual or asexual reproduction.
Malaria or Giardia are protozoa
Prokaryotic Cells - ANSWER single cells, no nucleus or organelles, reproduce
by providing in two (binary fission), bacteria are the smallest living cells.
Nucleic acid consists of single piece of DNA. Some bacteria contain plasmids.
Extrachromosomal, autonomous, self-replicating circular pieces of DNA.
Phenotypic classification - ANSWER Gram stain, culture characteristics
(hemolysis, pigment), Biotyping (based on biochemical reaction), Serotyping
(based on Ag-Ab reaction), Antibiogram (based on pattern of antibiotic
susceptibility), phase typing
,Genotypic classification - ANSWER Nucleic acid based methods. Rapid ID of
the organis, used for molecular fingerprinting methods (epidemiology)
Morphology of Bacteria - ANSWER Arrangement: usually single or in
chains/pairs/clusters
Special Structures: Capsules/flagella/pili/fimbriae/spores
Staining - ANSWER Gram and Acid Fast
Gram Stain - ANSWER Positive (purple)
Pink (pink)
Acid fast stain - ANSWER Acid fast (pink)
Non acid fast (blue-green)
Cocci - ANSWER spherical
Bacilli - ANSWER rod or elongated
Coccobacilli - ANSWER very short rods
Sphirochaetes - ANSWER spiral or coiled
Vibrios - ANSWER curved or comma shaped
Gram Staining - ANSWER 1. Crystal violet (1 min) - all purple
2. Gram's iodine (1 min) - all purple
3. Decolorize with alcohol (10 sec)
- G+ = purple
-G- = colorless
, 4. Counterstain with safranin (30 sec)
-G+ = Purple
-G- = Red
Wash with running water after every step
Rickettsia - ANSWER Obligate intracellular Gram negative rods which
produce a distinct category of disease.
Ex: Endemic/epidemic typhus. Rocy mountain spotted fever
Behaves more like a virus
Prokaryotic cell diagram - ANSWER
Flagella - ANSWER long coiled structures made up of the flagellin protein,
responsible for motility, chemotaxis. Antigenic
Fimbria (Pili) - ANSWER Made up of Pillin protein, thinner and more
numerous, adherence factors for the transfer of genetic material between
bacteria
Eukaryotic cell structure - ANSWER
Capsular Polysaccharide - ANSWER visualized by the India ink technique,
promotes adherence to host cell surfaces and other bacteria, capsule is major
virulence factor, but is poorly antigenic
EM of spore developing inside cell protective layer - ANSWER cortex, spore
coat
Medical importance of spores - ANSWER resistance to heat, desiccation,
radiation, disinfectants. Metabolically inactive, can become vegetative once
Complete Solution
Virus - ANSWER Neither eukaryote or prokaryote. Set of genes packaged in a
protein coat. May be covered by a lipid membrane derived from host cell.
Strictly intracellular. Either RNA or DNA, not both.
Bacteriophage - ANSWER Viruses that have infected bacteria
Eukaryotic Cells - ANSWER Nucleated cells, mitotic division, organelles
present, nuclear membrane present, multiple chromosomes
Fungi - ANSWER Yeast and molds, mostly free-living, eukaryotic cell
structure, but with rigid cel wall, Ergosterol in cell wall (but cholesterol in
animal cell walls)
Protozoa - ANSWER Single celled parasite. Hellminths are parasites too but
are macroscopic worms. Mostly free living. Sexual or asexual reproduction.
Malaria or Giardia are protozoa
Prokaryotic Cells - ANSWER single cells, no nucleus or organelles, reproduce
by providing in two (binary fission), bacteria are the smallest living cells.
Nucleic acid consists of single piece of DNA. Some bacteria contain plasmids.
Extrachromosomal, autonomous, self-replicating circular pieces of DNA.
Phenotypic classification - ANSWER Gram stain, culture characteristics
(hemolysis, pigment), Biotyping (based on biochemical reaction), Serotyping
(based on Ag-Ab reaction), Antibiogram (based on pattern of antibiotic
susceptibility), phase typing
,Genotypic classification - ANSWER Nucleic acid based methods. Rapid ID of
the organis, used for molecular fingerprinting methods (epidemiology)
Morphology of Bacteria - ANSWER Arrangement: usually single or in
chains/pairs/clusters
Special Structures: Capsules/flagella/pili/fimbriae/spores
Staining - ANSWER Gram and Acid Fast
Gram Stain - ANSWER Positive (purple)
Pink (pink)
Acid fast stain - ANSWER Acid fast (pink)
Non acid fast (blue-green)
Cocci - ANSWER spherical
Bacilli - ANSWER rod or elongated
Coccobacilli - ANSWER very short rods
Sphirochaetes - ANSWER spiral or coiled
Vibrios - ANSWER curved or comma shaped
Gram Staining - ANSWER 1. Crystal violet (1 min) - all purple
2. Gram's iodine (1 min) - all purple
3. Decolorize with alcohol (10 sec)
- G+ = purple
-G- = colorless
, 4. Counterstain with safranin (30 sec)
-G+ = Purple
-G- = Red
Wash with running water after every step
Rickettsia - ANSWER Obligate intracellular Gram negative rods which
produce a distinct category of disease.
Ex: Endemic/epidemic typhus. Rocy mountain spotted fever
Behaves more like a virus
Prokaryotic cell diagram - ANSWER
Flagella - ANSWER long coiled structures made up of the flagellin protein,
responsible for motility, chemotaxis. Antigenic
Fimbria (Pili) - ANSWER Made up of Pillin protein, thinner and more
numerous, adherence factors for the transfer of genetic material between
bacteria
Eukaryotic cell structure - ANSWER
Capsular Polysaccharide - ANSWER visualized by the India ink technique,
promotes adherence to host cell surfaces and other bacteria, capsule is major
virulence factor, but is poorly antigenic
EM of spore developing inside cell protective layer - ANSWER cortex, spore
coat
Medical importance of spores - ANSWER resistance to heat, desiccation,
radiation, disinfectants. Metabolically inactive, can become vegetative once
