Bacterial structures and characteristics

Question 1

3 main shapes of bacteria

Answer 1

cocci (spherical), bacilli (rod), spirochetes (spiral)

Question 2

external structures

Answer 2

flagellum (propeller), cilia (back and forth), fimbria/pili (adhere, sex)

Question 3

Glycocalyx

Answer 3

slime layer (polysccride coating secreted to exterior of cell) adhesion and protection

Question 4

capsule

Answer 4

gelatinous layer surrounding whole bacterium - composed of polysaccharides (sugars identify specific types of bacterium)
Slippery - avoid phagocytosis . antibodies

Question 5

cell wall

Answer 5

external to cell membrane - prevents osmotic damage (outer membrane and inner membrane - strength due to peptidoglycan)

Question 6

gram positive

Answer 6

• no space, instead species secrete exoenzymes that digest material extracellularly.
  
  • Thin and simple outer membrane or none
  • Inner membrane is thick
  • No exotoxins
    Gram stain- purple color

Question 7

gram negative

Answer 7

• periplasmic space contains loose network of peptidoglycan strands and a gel. Produces antibiotic destroying enzymes (example - penicillinase)
  
  • Complex outer membrane
  • Inner membrane is thin
  • Exotoxins produced by LPS layer of outer membrane
  • Grain stain - pink/red color

Question 8

acid stain

Answer 8

Crystal violet, iodine, alcohol, safranin

Question 9

cell membrane

Answer 9

• Phospholipid bilayer containing protein
  
  • Functions indirectly in the synthesis of proteins used as wall precursors
  • Ribosomes - protein synthesis In cytoplasm and cell membrane
  • 30s (subunit) + 50s (subunit) –> 70s ribosome (compared to 80S in eukaryotic mammalian cells)

Question 10

nucleiod/material

Answer 10

one singular circular chromosome (2000 genes) - no nuclear membrane

Question 11

identification

Answer 11

once known as gram positive or gram negative, go under different tests w nutrients, temperatures, humidity, and gaseous requirements
○ Final identification is made on the basis of bacterial color, morphology, cellular arrangement, and colony appearance

Question 12

Conditions for growth

Answer 12

temperature, pH, Gasesous requirements, nutritional requirements

Question 13

generation time

Answer 13

the time required for doubling of bacterial numbers

Question 14

lag phase

Answer 14

nutrients mobilized, metabolic activity increases, mesosomes form in prep for binary fission

Question 15

long phase

Answer 15

rapid and steady exponential increase in cell numbers (doubling or generation of time mean for one cell)

Question 16

plateau phase

Answer 16

number of new cells equals the number of dying (nutrients being depleted) maximal cell yield

Question 17

decline phase

Answer 17

number of organisms declines faster than new cells are replaced

Question 18

obligate aerobes, anaerobes, facultative anaerobes

Answer 18

aerobes - O2
Anaerobes - no O2
facultative - O2 and no O2

Question 19

nonmenclature

Answer 19

Genus name is first, species name listed next (lower case)

Question 20

Prokaryotic cells

Answer 20

single chromosomes, Binary fission, sex pills, metabolisms with cell membrane, primitive ribosomes, simple flagella, peptidoglycan walls

Question 21

Eukaryotes

Answer 21

multiple chromosomes, DNA is membrane bond in nucleus, mitosis, sexual reproduction, metabolisms in mitochondria, complex ribosmoones in cytoplasm, primitive in mitochondria, complex flagella, cellulose walls

Question 22

Etiologic agent

Answer 22

bodily fluid sample, diagnose and subscribe antimicrobial agent to fight infection

Question 23

empirical treatment

Answer 23

subscribed becuase advanced infection, can’t wait for incubation results

Question 24

antibiotics

Answer 24

Substances of microbial origin that , in small amounts, supress the growth of other microbes (subpress symptoms of illness

Question 25

Chemotherapeutic agents

Answer 25

Substances chemically synthesized and used in treatment of such disease (drugs action is directed at the cause of the illness)

Question 26

Semisynthetic agents

Answer 26

Hybrid compound produced by microbe and modified chemically for certain properties.

Question 27

Antibiotic sensitivity testing

Answer 27

• Used to determine the most effective antibiotic against a particular strain of microorganism.
• Bodily fluid samples grown (optimal growth 36-48 hours) in favourable conditions on a supportive medium
• Zone of inhabitation - if species is susceptible to antibiotic (antibiotic leaches out and supresses colonies growth

Question 28

Minimal inhibitory concentration

Answer 28

(MIC) of an antibiotic is the lowest concentration that inhibits the visible growth of a microorganisms (24 hours)

Question 29

minimal bactericidal concentration

Answer 29

(MBC) is the lowest concentration of antibiotic that kills the test organism. (yields no growth)

Question 30

Resistant microorganisms

Answer 30

Low-level exposure, random genetic variation, surviving microbes, virulent, natural resistance, random genetic mutation, selection pressure, transfer of genetic material

Question 31

subdivisions of microbiology

Answer 31

1) Bacteriology (Bactria, chlamydia, rickettsiae)
2) Virology (viruses)
3) Mycology - fungi (molds, yeasts)
4) Parasitology (protozoology - protozoa, helminthology - worms)
5) Phycology - algea

Question 32

commensalism

Answer 32

No invasion, Benefits microbe, human is not harmed. Ex) most oral microbes

Question 33

Eukaryotic cells

Answer 33

Complex - animals, green plants, and fungi

Question 34

Genus name

Answer 34

Large group of characteristics that are related (Think of last name)

Question 35

mutualism

Answer 35

No invasion, benefits human and microbe. Ex) vit A produced in gut

Question 36

parasitism

Answer 36

Invasion, benefits microbe, harms human. Ex) Hepatitis, influenza

Question 37

prokaryotic cells

Answer 37

simple - bacteria

Question 38

species name

Answer 38

specific characteristics (think of first name)

Question 39

Pure microbiology

Answer 39

subdivided into several classifications: bacteriology, virology, mycology, parasitology, phycology and immunology

Question 40

Applied microbiology

Answer 40

medical, pharmaceutical, industrial, food, agricultural, enviroemtonal, water, air