Micro Exam #4

Front 1

postulated that rabies was caused by a virus in 1884

Back 1

Louis Pasteur

Front 2

Showed a disease in tobacco was caused by a virus in 1890s

Back 2

Ivanovski & Beijerinck

Front 3

TRUE OR FALSE: Viruses are obligate intracellular parasites.

Back 3

true

Front 4

protein coats that enclose and protect their nucleic acid

Back 4

capsid

Front 5

The capsid together with the nucleic acid is the...

Back 5

nucleocapsid

Front 6

Some viruses have an external covering called an ___________ made from the phospholipid bilayer; viruses lacking this feature are naked

Back 6

envelope

Front 7

What are the two structural capsid types?

Back 7

helical and icosahedral

Front 8

exposed proteins on the outside of the envelope; essential for attachment of the virus to the host

Back 8

spikes

Front 9

Name two functions of the capsid/envelope.

Back 9

protect the nucleic acid & help the virus bind to a cell surface

Front 10

_________ lacks a typical capsid and is covered by a dense layer of lipoproteins.

Back 10

poxvirus

Front 11

Some _____________ have a polyhedral nucleocapsid along with a helical tail and attachment fibers.

Back 11

bacteriophages

Front 12

A _____________ can either be DNA or RNA but never both.

Back 12

viral genome

Front 13

What is the function of a viral genome?

Back 13

carry genes necessary to invade host cell and redirect cell's activity to make new viruses

Front 14

usually double stranded; circular or linear

Back 14

DNA viruses

Front 15

usually single stranded, may be double stranded, may be segmented into separate pieces

Back 15

RNA viruses

Front 16

ssRNA genomes ready for immediate translation are...

Back 16

positive-sense RNA

Front 17

ssRNA genomes that must be converted into proper form are...

Back 17

negative-sense RNA

Front 18

binding of virus to specific molecules on the host cell

Back 18

adsorption

Front 19

genome enters the host cell

Back 19

penetration

Front 20

the viral nucleic acid is released from the capsid

Back 20

uncoating

Front 21

viral components are produced

Back 21

synthesis

Front 22

new viral particles are constructed

Back 22

assembly

Front 23

assembled viruses are released by budding (exocytosis) or cell lysis

Back 23

release

Front 24

Put the following in order of operation: release, synthesis, adsorption, penetration, uncoating, assembly

Back 24

Adsorption, penetration, uncoating, synthesis, assembly, release

Front 25

spectrum of cells a virus can infect

Back 25

host range

Front 26

What is the host range of Hepatitis B?

Back 26

human liver cells

Front 27

What is the host range of Poliovirus?

Back 27

primate intestinal and nerve cells

Front 28

What is the host range of rabies?

Back 28

various cells of many mammals

Front 29

entire virus is engulfed and enclosed in a vacuole or vesicle

Back 29

endocytosis

Front 30

envelope merges directly with membrane resulting in nucleocapsid's direct entry into cytoplasm

Back 30

fusion

Front 31

When do endocytosis and fusion occur?

Back 31

penetration/uncoating

Front 32

Positive-sense RNA contain the message for _________.

Back 32

translation

Front 33

Negative-sense RNA must be converted into _________.

Back 33

positive-sense message

Front 34

exocytosis; nucleocapsid binds to membrane which pinches off and sheds the viruses gradually; cell is not immediately destroyed

Back 34

budding

Front 35

nonenveloped and complex viruses released when cell dies and ruptured

Back 35

lysis

Front 36

During what phase do budding and/or lysis occur?

Back 36

release

Front 37

What are the 5 types of cytopathic effects?

Back 37

changes in size and shape, cells fuse to form multinucleate cells, cell lysis, alter DNA, transform cells into cancerous cells

Front 38

cell harbors the virus and is not immediately lysed

Back 38

persistent infections

Front 39

can last weeks or a host's lifetime; several can periodically be reactive

Back 39

chronic latent state

Front 40

Describe the measles virus chronic latent state.

Back 40

may remain hidden in brain cells for many years

Front 41

Describe the herpes simplex virus chronic latent state.

Back 41

cold sores and genital herpes.

Front 42

Describe the herpes voster virus chronic latent state.

Back 42

chickenpox and shingles

Front 43

Viruses are the most common cause of ________ infections.

Back 43

acute

Front 44

misfolded proteins; contain no nucleic acid; extremely resistant to usual sterilization techniques; cause transmissible spongiform encephalopathies

Back 44

prions

Front 45

Scrapie is common in...

Back 45

sheep and goats

Front 46

Bovine spongiform encephalopathies is also known as...

Back 46

mad cow disease

Front 47

Wasting disease is common in...

Back 47

elk

Front 48

Creutzfeldt Jakob Syndrome is common in...

Back 48

people who eat brains

Front 49

Prions and bacterial endospores have what relative resistance of microbes?

Back 49

highest

Front 50

Name 4 bacteria that have moderate resistance.

Back 50

pseudomonas sp., mycobacterium tuberculosis, s. aureus, protozoan cysts

Front 51

Name 4 bacteria with the least resistance.

Back 51

most vegetative cells, fungal spores, hyphae yeast, enveloped viruses, and protozoan trophozoites

Front 52

process that destroys all viable microbes, including viruses and endospores

Back 52

sterilization

Front 53

process to destroy vegetative pathogens, not endospores; inanimate objects

Back 53

disinfection

Front 54

disinfectants applied directly to exposed body surfaces

Back 54

antiseptic

Front 55

any cleansing technique that mechanically removes microbes

Back 55

sanitization

Front 56

Name 6 factors that affect death rate.

Back 56

number, nature, temperature, pH, concentration of agent, mode of action of the agent, presence of solvents, organic matter, or inhibitors

Front 57

Name two cellular targets of physical and chemical agents.

Back 57

cell wall and cell membrane

Front 58

What happens to the cell wall when it is targeted by physical and chemical agents?

Back 58

cell wall becomes fragile and cell lyses; some antimicrobial drugs, detergent and alcohol

Front 59

What happens to the cell membrane when it is targeted by physical and chemical agents?

Back 59

loses integrity; detergent surfactants

Front 60

Name the other two cellular targets of physical and chemical agents.

Back 60

protein and nucleic acid synthesis; proteins

Front 61

What happens when protein and nucleic acid synthesis is targeted by physical and chemical agents?

Back 61

prevention of replication, transcription, translation, peptide bond formation, protein synthesis, chloramphenicol, uv radiation, formaldehyde

Front 62

What happens when proteins are targeted by physical and chemical agents?

Back 62

disrupt or denature proteins; alcohols, phenols, acids, heat

Front 63

Name the 5 methods of physical control.

Back 63

heat, cold temps, desiccation, radiation, filtration

Front 64

Moist heat, as compared to dry heat, has _________ temperatures and __________ exposure time.

Back 64

lower; shorter

Front 65

heat is applied to kill potential agents of infection and spoilage without destroying the food flavor or value

Back 65

pasteurization

Front 66

Why is pasteurization not considered sterilization?

Back 66

kills non-spore-forming pathogens and lowers microbe count, does not kill endospores or many nonpathogenic microbes

Front 67

from of dry heat using flame or electric heating coil; ignites and reduces micros and other substances

Back 67

incineration

Front 68

What do dry ovens do to proteins?

Back 68

coagulate them

Front 69

What do cold temperatures do to microbes?

Back 69

slows growth

Front 70

What is the term used to describe slowed growth of microbes?

Back 70

microbiostatic

Front 71

gradual removal of water from cells, leads to metabolic inhibition; not effective microbial control- many cels retain ability to grow when water is reintroduced

Back 71

desiccation/dehydration

Front 72

freeze drying; preservation

Back 72

lyophilization

Front 73

deep penetrating power that has sufficient energy to cause electrons to leave their orbit, breaks DNA; used to sterilize medical supplies and food products

Back 73

ionizing radiation

Front 74

little penetrating power so it must be directly exposed; UV light creates pyrimidine dimers, which interfere with replication

Back 74

nonionizing radiation

Front 75

physical removal of microbes by passing gas or liquid through filter; used to sterilize heat sensitive liquids and air in hospital isolation units and industrial clean rooms

Back 75

filtration

Front 76

level of germicide that kills endospores; may be sterilants; devices that are not heat sterilizable and intended to be used in sterile environments

Back 76

high-level germicides

Front 77

level of germicide that kills fungal spores, tubercle bacillus, and viruses; used to disinfect devices that will come in contact with mucous membranes but are not invasive

Back 77

intermediate-level

Front 78

eliminate only vegetative bacteria, vegetative fungal cells, and some viruses; clean surfaces that touch skin but not mucous membranes

Back 78

low-level

Front 79

Name 4 factors that affect germicidal activity of chemicals.

Back 79

nature of material being treated, degree of contamination, time of exposure, strength and chemical action of the germicide

Front 80

act as surfactants dissolving membrane lipids and coagulating proteins of vegetative bacterial cells and fungi; intermediate

Back 80

alcohols

Front 81

works against all bacteria and many endospores, fungi, and viruses; alters plasma membranes

Back 81

iodine

Front 82

produce highly reactive hydroxyl-free radicals that damage protein and DNA while also decomposing oxygen has; antiseptic at low concentrations; sporicidal if a strong solution is used

Back 82

hydrogen peroxide

Front 83

act as surfactants that alter membrane permeability of some bacteria and fungi; low level of decontamination

Back 83

quaternary ammonia compounds (quats)

Front 84

mechanically remove soil and grease containing microbes

Back 84

soaps