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Flashcards in I - Generalities Deck (135):
1

Cells: DNA within a nuclear membrane

Eukaryotes

2

Cells: Uses mitotic division

Eukaryotes

3

Cells: DNA associated with histones

Eukaryotes

4

Cells: Has more than one chromosome

Eukaryotes

5

Cells: Has membrane-bound organelles

Eukaryotes

6

Eukaryotes: Ribosomes

40s + 60s = 80s

7

Cells: DNA within a nucleiod

Prokaryotes

8

Cells: Uses binary fission

Prokaryotes

9

Cells: Has only one chromosome

Prokaryotes

10

Prokaryotes: Ribosomes

30s + 50s = 70s

11

Cell Walls: Plants & Algae

cellulose

12

Cell Walls: Fungi

chitin

13

Cell Walls: Diatoms

silica

14

Cell Walls: Prokaryotes

peptidoglycan

15

Cell Walls: Archaea

pseudopeptidoglycan

16

Cell Walls: Protozoa & Animals

none

17

An ancestral eukaryotic cell is thought to have engulfed the bacterial ancestor of

mitochondria

18

An early eukaryotic cell, already possessing mitochondria, engulfed a photosynthetic bacterium and retained it in symbiosis resulting in

chloroplasts

19

Microorganisms: Has cells

bacteria, fungi, protozoa & helminths

20

Microorganisms: 0.02-0.2 μm

viruses

21

Microorganisms: 1-5 μm

bacteria

22

Microorganisms: 3-10 μm

fungi (yeasts)

23

Microorganisms: 15-25 μm

protozoa & helminths (trophozoites)

24

Microorganisms: Has either DNA or RNA

viruses

25

Microorganisms: Has both DNA & RNA

bacteria, fungi, protozoa & helminths

26

Microorganisms: Has no nucleus

viruses

27

Microorganisms: Has prokaryotic nucleoid

bacteria

28

Microorganisms: Has eukaryotic nucleus

fungi, protozoa & helminths

29

Microorganisms: Has no ribosomes

viruses

30

Microorganisms: Has 70s ribosomes

bacteria

31

Microorganisms: Has 80s ribosomes

fungi, protozoa & helminths

32

Microorganisms: Doesn't have mitochondria

viruses, bacteria

33

Microorganisms: Has mitochondria

fungi, protozoa & helminths

34

Microorganisms: Has a protein capsid and lipoprotein envelope

viruses

35

Microorganisms: Has a rigid wall with peptidoglycans

bacteria

36

Microorganisms: Has a rigid wall with chitin

fungi

37

Microorganisms: Has a flexible membrane

protozoa & helminths

38

Microorganisms: Motile

some bacteria, most protozoa & helminths

39

Microorganisms: Replicates via Binary Fission

bacteria

40

Microorganisms: Replicates via Budding or Mitosis

fungi

41

Microorganisms: Replicates via Mitosis alone

protozoa & helminths

42

Obligate intracellular but acellular parasites of plants, naked RNA, no human diseases

viroids

43

Mobile genetic elements

Transposons

44

DNA pieces that move readily from one site to another either within or between the DNA of bacteria, plasmids and bacteriophages

"jumping genes" (transposons)

45

DNA replication followed by insertion of a new copy into another site

Replicative Transposition

46

DNA is excised from the site without replicating and then inserts into the new site

Direct Transposition

47

Prions: Normal form of protein encoded by the host's chromosomal DNA, suceptible to protease and soluble in detergent

PrPc

48

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

49

Appearance of vacuolated neurons with loss of function and lack of immune response or inflammation

Spongiform Encephalopathies

50

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)

51

Animal Prion Diseases

Scrapie (sheep/goat), Transmissible Mink Encephalopathy, Bovine Spongiform Encephalopathy (Mad Cow), Chronic Wasting Disease (mule/deer/elk)

52

Prions are _____ to standard viral disinfection procedures and have very long incubation periods as long as ____.

impervious, 30 years

53

Prions: Transmission

infected tissue, cuts in skin, transplantation of contaminated tissue (cornea), contaminated medical devices (brain electrodes), ingestion of infected tissue (cannibalism), inherited

54

Prions: Susceptible Populations

women and children of the Fore tribe in New Guinea, neurosurgeons, neurosurgery patients, transplant surgeons, transplant patients

55

Prions: Spectrum of Disease

loss of muscle control → shivering → myoclonic jerks and tremors → loss of coordination → rapidly progressive dementia → death

56

Prions: Treatment

none

57

Prions: Prevention

cessation of ritual cannibalism, elimination of animal products from livestock feed, disinfection of neurosurgical tools (5% hypochlorite, Na hydroxide, autoclaved at 15psi for 1 hour)

58

Bacteria: Spheres

cocci

59

Bacteria: Rods

bacilli

60

Bacteria: Spirals

spirochetes

61

Cocci: Pairs

diplococci

62

Cocci: Chains

streptococci

63

Cocci: Clusters

staphylococci

64

Smallest Bacteria

Mycoplasma

65

Largest Bacteria

Thiomargarita namibiensis

66

Largest Medically Relevant Bacteria

Borrelia burgdorferi

67

All bacteria have a cell wall composed of peptidoglycan except

Mycoplasma

68

sugar + peptide side-chains crosslinked by transpeptidase

peptidoglycan

69

Kill bacteria by cleaving the glycan backbone (β 1→4 linkage between GlcNAc and MurNAc) of the peptidoglycan

lysozymes

70

Facilitate the passage of small, hydrophilic molecules into the cell

porin proteins

71

Have thicker and multilayered peptidoglycan and teichoic acid

Gram (+)

72

Have thinner and single-layered peptidoglycan, lipopolysaccaride and periplasmic space

Gram (-)

73

The outer membrane of gram (-) bacteria contains _____ which consists of _____ and _____.

endotoxin (lipopolysaccharide), lipid A, O antigen

74

Only gram (+) bacteria with endotoxin

Listeria monocytogenes

75

Steps in Gram Staining

primary stain (crystal Violet) → mordant (Iodine) → decolorizing agent (Acetone) → counterstain (Safranin)

76

Bacteria not seen in Gram Stain

Treponema, Rickettsia, Mycobacteria, Mycoplasma, Legionella, Chlamydia

77

Essential Components of Bacteria: Lipoprotein bilayer without sterols

cytoplasmic membrane

78

Essential Components of Bacteria: Site of oxidative and transport enzymes

cytoplasmic membrane

79

Essential Components of Bacteria: RNA and protein in 50s and 30s subunits

ribosomes

80

Essential Components of Bacteria: Protein synthesis

ribosomes

81

Essential Components of Bacteria: DNA, genetic material

nucleoid

82

Essential Components of Bacteria: Invagination of plasma membrane

mesosome

83

Essential Components of Bacteria: Participates in cell division and secretion

mesosome

84

Essential Components of Bacteria: Space between the plasma membrane and outer membrane

periplasm

85

Essential Components of Bacteria: Contains many hydrolytic enzymes including β-lactamases

periplasm

86

Non-Essential Components of Bacteria: Polysaccharide, protects against phagocytosis

capsule

87

Non-Essential Components of Bacteria: Glycoprotein, attachment, conjugation

pilus, fimbria

88

Non-Essential Components of Bacteria: Polysaccharide, mediates adherence to surfaces, biofilm

glycocalyx

89

Non-Essential Components of Bacteria: Protein, motility, H antigen (flagellin protein)

flagellum

90

1 Flagellum

Monotrichous

91

2 Flagella

Amphitrichous

92

Tuft of Flagella

Lophotrichous

93

Side Flagella

Peritrichous

94

Non-Essential Components of Bacteria: Keratin-like coat, dipicolinic acid, resistance to heat and chemicals

spore

95

Non-Essential Components of Bacteria: DNA, genes for antibiotic resistance and toxins

plasmid

96

Non-Essential Components of Bacteria: Glycogen, lipids, polyphosphates, site of nutrients in cytoplasm

granule

97

All bacterial capsules are composed of polysaccharide except

Bacillus anthracis (polypeptide of D-glutamate)

98

The capsule of Bacillus anthracis is composed of

polypeptide of D-glutamate

99

Formed by gram (+) rods especially Bacillus and Clostridium

spore

100

Extrachromosomal, double-stranded, circular DNA capable of replicating independently of the bacterial chromosome, can sometimes be integrated into the bacterial chromosome

plasmids

101

Plasmids: From cell to cell by conjugation, large, contain about a dozen genes for synthesis of the sex pilus and for the enzymes required for transfer

transmissible plasmids

102

Plasmids: Small, do not contain the transfer genes, frequently present in many (10-60) copies per cell

non-transmissible plasmids

103

Bacterial Growth Curve: Cells are depleted of metabolites as the result of unfavorable conditions, adaptation to new environment, nutrients are incorporated, vigorous metabolic activity but do not divide (zero growth rate)

Phase 1: Lag Phase

104

Bacterial Growth Curve: Rapid cell division occurs, β-lactam antibiotics act during this phase (constant growth rate), continues until either one or more nutrients in the medium become exhausted or toxic metabolites accumulate and inhibit growth

Phase 2: Log or Exponential Phase

105

Bacterial Growth Curve: Exhaustion of nutrients or the accumulation of toxic products cause growth to cease completely (zero growth rate), spores are formed

Phase 3: Maximum Stationary Phase

106

Bacterial Growth Curve: Most of the cells die because nutrients have been exhausted (negative growth rate)

Phase 4: Decline or Death Phase

107

Oxygen metabolism generates toxic products such as

superoxide, hydrogen peroxide

108

Enzymes needed to survive in aerobic environments

superoxide dismutase, peroxidase, catalase

109

Aerobic Bactera: Completely dependent on oxygen for ATP-generation

Obligate Aerobes

110

Aerobic Bactera: Uses fermentation but can tolerate low amounts of oxygen (< 0.2 atm) because they have SOD

Microaerophiles

111

Anaerobic Bactera: Utilize oxygen if it is present but can use fermentation in its absence

Facultative Anaerobes

112

Anaerobic Bactera: Exclusively anaerobic but insensitive to the presence of oxygen

Aerotolerant Anaerobes

113

Anaerobic Bactera: Cannot grow in the presence of oxygen because they lack 3 important enzymes

Obligate Anaerobes

114

Obligate Aerobes

Nocardia, Neisseria, Pseudomonas, Mycobacteria, Mycoplasma pneumoniae, Bordatella, Brucella, Bacillus cereus, Legionella, Leptospira

115

Obligate Anaerobes

Actinomyces, Bacteroides, Clostridium

116

Microaerophiles

Borrelia, Treponema, Campylobacter, Helicobacter, Streptococcus

117

Facultative Anaerobes

Bacillus anthracis, Escherichia coli, Listeria, Corynebacterium, Mycoplasma (non-pneumoniae), Staphylococcus

118

Aerotolerant Anaerobes

Propionibacterium, Lactobacillus vaginalis

119

Bacterial genetic material consists of _____ located in the _____.

single chromosome of circular DNA, nucleoid

120

Bacteria are _____ while eukaryotic cells are _____.

bacteria - haploid, eukaryotes - diploid

121

Bacterial DNA is _____ while human DNA is _____.

bacteria - circular, humans - linear

122

Extrachromosomal pieces of DNA encoding both exotoxins and enzymes

plasmids

123

DNA that moves readily from one site on the bacterial chromosome to another or from the bacterial chromosome to a plasmid

transposons

124

Movement of genes from inactive storage sites into active sites of transcription

Programmed Rearrangements

125

Prokaryote DNA transfer from one bacterium to another

Conjugation

126

Prokaryote DNA transfer by a virus from one cell to another

Transduction

127

Purified prokaryote/eukaryote DNA taken up by a cell

Transfromation

128

Cycles of Transduction

Lytic, Lysogenic

129

Occurs when normal flora occupy receptor sites preventing pathogens from binding

Colonization Resistance

130

Normal Flora: Skin

Staphylococcus epidermidis

131

Normal Flora: Nose

Staphylococcus aureus (anterior nares)

132

Normal Flora: Mouth

Viridans Streptococci

133

Normal Flora: Dental Plaque

Streptococcus mutans

134

Normal Flora: Colon

Bacteroides, Escherichia coli

135

Normal Flora: Vagina

Lactobacillus vaginalis (Döderlein), Escherichia coli, Streptococcus agalactiae