Microbiology 1 Review 1

Front 1

What do microbiology and its branches study?

Back 1

study of microorganisms such as bacteria, viruses, fungi, animal paracites, protaazoa

Front 2

What microorganisms are prokaryotic, eukaryotic, or noncellular?

Back 2

prokaryotic- bacteria
eukaryotic - fungi
viruses - non cellular
(yeasts-unicellular, molds-multicellular)

Front 3

Describe the characteristics of microorganisms.

Back 3

 Characteristics of microorganisms:
► Widespread distributation
► Maintenance of ecological balance
► Benefits for the body
► Normal flora: resident and transient
► Superinfection-opportunistic
► Only a minority of micro organisms are pathogenic
► Host-microbe interaction
-Disease causing properties of micro organisms
-Body's defense mechanisms
► Food and beverage industry
-Are in beer and wine

Front 4

What is normal flora and where is it located?

Back 4

are located in the nose, throat, skin, eyes, intestinal tract, and reproductive tracts and are a collection of microbes that do not cause disease

Front 5

5.Calculate actual size starting at 100 of an object that is being viewed under a microscope. Figure the original size.

Back 5

---10x10=100 ...100 times with original size at 1
---200 size microscope ocular lens and objective lens is 10x and 40x origingal size is 200/400 =1.5 or 1 and 1/2 starting original size

Front 6

6. What 3 factors affect observation under a compound light microscope?

Back 6

magnification, resolution, contrast

Front 7

7.Describe the difference between light microscope and electron microscope.

Back 7

electron uses electron beams instead of light, and electromagnetic instead of glass lenses.

Front 8

8. Describe the difference between TEM and SEM.

Back 8

..TEM is two-dimensional, SEM is three-dimensional

Front 9

9. What is a simple staining?

Back 9

..Using an aqueous or alcohol solution of a single basic dye, and possibly a mordant to increase the affinity for the stain.

Front 10

Why is a mordant used?

Back 10

to increase the affinity of the stain to the microbe

Front 11

Describe details of Gram Stain.

Back 11

bacteria are divided into 2 groups, gram negative and gram positive.
Procedure on a heat fixede smear add a basic dye crystal violet applied as primary stain shows purple. Wash off with water and add iodine as a mordant. Rinse w/alcohol(decolorization) a basic dye (safranin) is used as a counter stain to compare wash off water blot dry gram + shows purple and gram negative shows pink

Front 12

what does acid fast staining identify?

Back 12

It only binds to bacteria that have a waxy material in their cells to identify bgacteria in genus Mycobacterium

Front 13

what structure shows from negative staining?

Back 13

capsules, gelatinous covering on some bacterial cells. Stain back

Front 14

describe characteristics of typical prokarotic cells.

Back 14

bacteria that lack membrane bound nuclei or organelles. But they have cell walls and metabolism occurs in cell membrane

Front 15

How are bacterial cells arranged?

Back 15

Cocci : diplococcic (in pairs) streptococci (chainlike patterns) and staphylococci (grapelike clusters)
Bacilli: diplobacilli(in pairs) streptobacilli(in chains) and cocobacilli (like cocci) but mostly are single rods
Spirals: one or more twists, never straight, including vibrio (like comma, spirillum (like corkscrew)with flagella, and spirochete (helical and flexible without flagella

Front 16

What are bacterial capsules?

Back 16

Capsule: firmly attached to the cell wall, determined by negative staining, and contribute to the bacterial virulence (because bacteria are protected from phagocytosis

Front 17

What's the function of bacterial flagella?

Back 17

Flagella meaning “whip” long threadlike (filamentous) appendages, propel bacteria, provide motility

Front 18

Whats the difference between Fimbriae and pili?

Back 18

Fimbriae and pili: thin, short surface appendages, fimbriae help cell adhesions, while pili join cells for the transfer of DNA between cells

Front 19

What bacteria lack a cell wall?

Back 19

mycoplasma

Front 20

How are plasmids different from bacterial chromosomes?

Back 20

extra chromosomal genetic material (DNA) that are'nt crucial for cells survival but carry genes for antibiotic resistance tolerance for toxic metals, production of toxins, synthesis of enzyme can be transferred to another bacteria thru pili. Plasmids are used for gene manipulaiton. Bactgerial chromosomes are the cells DNA in the Nuclear region, they are critical for the bacterial cell's survival.

Front 21

What are the characteristics of bacterial endospores?

Back 21

resting structures formed by genus Clostridium and Bacillus for survival in adverse envionmental conditions. Process of formation = Sporation , return to vegetative state is germination(revive when H2O becomes available, etc)

Front 22

23. Describe the nutritional patterns (energy and carbon sources) of microrganisms.

Back 22

slide 27 (functional anatomy PP)....
light phototrophs and chemical>chemotrophs>chemoheterotrophs (most medically important microorganisms)

Front 23

24. What are the physical requirements for microbial growth?

Back 23

temperature, PH, and osmotic pressure

Front 24

25. what does an acidophile need for growth?

Back 24

Acid

Front 25

***26.Define psychrophiles, psychrotrophs, mesophiles, thermophiles, and hyperthermophiles.

Back 25

phychro-cold loving max growth at 10 degrees celcius
psychrotorophs= max growth 20
mesophiles=moderate temp, max 37
thermo=max growth at 60
hyperthermophile=extreme temp 90

Front 26

27.What are the chemical requirements for microbial growth?

Back 26

Water
Carbon source
Nitrogen
Nitrogen fixation from the atmosphere
Sulfur
Trace metallic elements
Molecular oxygen requirments
Other chemicals (organic growth factors)

Front 27

***28.Define obligate aerobes, facultative anaerobes, obligate anaerobes, aerotolerant anaerobes, and microaerophiles.

Back 27

obligate aerobes=must have oxygen to live
facultative anaerobes=grow best in the presence of oxygen, but can grow in its absence
obligate anaerobes=unable to use oxygen and are harmed by it?
aerotolerant anaerobes=cannot use oxygen for growth but tolerate it fairly well
microaerophiles=grows only in oxygen concentrations lower than in air

Front 28

29.Why is agar commonly used for a culture medium?

Back 28

it does not liquify at room temperature, is not utilized by microorganisms, and does not inhibit microbial growth

Front 29

30.Distinguish among chemically defined media, complex media, reducing media, selective media, and differential media.

Back 29

chemically defined media=exact chemical compisition known
complex media=not known
reducing media=chemically remove o2 so can grow anarobes
selective media=allow growth of only desired microbes
differential media=distinguish among disired microbes plus ones growing on the same plate, but showing different appearence.

Front 30

31.Why must certain microorganisms be cultivated in living animals or in cell cultures?

Back 30

cuz they are picky …need multiple growth factors

Front 31

32.What technique is used to obtain a pure culture from a mixed culture? p. 11 syllabus

Back 31

streak plate technique

Front 32

33.Calculate bacterial cell growth

Back 32

. Answer: 1 dollar to double 2,4,8>>>this is called generation >>>How many generations are 512 cells are 9 generations

Front 33

34.Describe the four phases of bacterial cell growth

Back 33

Lag phase=little or no change in number of cells but metabolic activity is high
log or exponetial = bacteria multiply at fastest reate possible under the conditions provided, and are most sensitve to antibiotics
stationary= there is equilibrium between cell division and death
death or logarithmic decline phase= number of deaths exceeds the number of new cells formed

Front 34

35.Explain the standard plate counts.

Back 34

p. 12 under STandard plate counts
reflect # of viable microbes assumeeach grows into a single colony,usually plates between 30-300 are counted using serial dilut
Pour plate method=inoculate empty

Front 35

36.Calculate the number of bacteria per ml

Back 35

number of bacteria per ml of clonies on the plate times the dilutional factor (1 ml of original inoculation is transferred to at test tube containing 9ml making a 1:10 dilution then 1ml of that dilution is transferred to a 2nd tube also containg 9ml broth making a dilution of 1:100, etc.
dissolution factor is 13 cells on plate 1:10,000 dilutiona>>>130,000

Front 36

37.Define sterilization, disinfection, antisepsis, germicide, bacteriostasis, asepsis, degerming, and sanitization

Back 36

steriization=destroys all microbes, including spores
disinfection=disinfecting surfaces
germicide=chemical agent that destroys microbes
bacteriostasis=refrigeration--bacteria are slowed down but not killed
asepsis=abscense of pathogensfrom an object or area(masks, gloves, UV light, gowns, filtration)
degerming=alcohol swabls or iodine remove microbes from skin
sanitization=reduciton of pathogens of eating utensils for safe health levels by mechanical cleanising or chemicals like dishwashing soap

Front 37

38.What are the physical methods of microbial control?

Back 37

heat
filtration
low temp
high pressure
dessicaiton (drying)
osmotic pressure (salt or sugar for cell osmisis)
radiation

Front 38

39.What are the chemical methods of microbial control?

Back 38

phenols
biguanides (chlorhexidine)
halogens
alcohols
heavy metals and their compounds
chemical food preservatives
alsehydes
gaseous chemsterilizers
peroxygens (oxidizing agents)

Front 39

40.Describe the uses of chlorhexidine, alcohols, and ethylene oxide

Back 39

chorhexadine=antiseptic disinfection of skin, antiseptic
alcohols=degerming removing transient microbes from skin
ethylene oxide= sterilization destroying all forms of microbial like on an object or material (acupunctue needles)

Front 40

41.Describe the mechanisms of antiseptics and disinfectants

Back 40

antiseptics=chemical disinfection other living tissues and can use on objects too
disinfection= reduce or inhibit microbial growth on inanimate objects

Front 41

42.How is bacterial gene expression regulated?

Back 41

aimed at mRNA synthesis and regulating transcription and subsequently translation, DNA to RNA=transcription
RNA to gene product= translation (expression of gene...When a gene is expressed, DNA is transcribed to produce RNA, which is then translated into proteins

Front 42

43.Compare Lac operon with Trp operon in all aspects.

Back 42

Operon models:
Lac operon (inducible system)...E. Coli uses this method in order to metabolize lactose
Trp operon (repressible system)...E. Coli synthesizes tryptophan
Difference=lac operon, the regulatory gene next to the promoter codes fro an ACTIVE repressor protien and in trP operon the repressible system, the regularoy gene next to the promoter codes for an INACTIVE repressor protein

Front 43

44.Define mutation, transformation, conjugation, and transduction

Back 43

mutation=A change in base sequence of DNA that creates a change in the genetic code that results in a change in the gene product, also changes based in base sequence of DNA > changes in genetic code > changes in gene product (protein)

transformation=process of transferring one part of DNA from one bacterium to another as "naked" DNA

conjugaiton= process where plasmid DNA is transferred from one cell to another through pili
transduciton=process where DNA is passed from one bacterium to another through a bacteriophage

Front 44

45.Describe the procedures and applications of recombinant DNA technology.

Back 44

DNA that has been artificially manipulated to combine genes from 2 different sources(genetic engineerring)