Bio 175 - Physical and Chemical Controls of Microbes Quiz

Asepsis

practices that prevent infection of sterile tissue

microbial death

defined as the inability of microbe to reproduce even under ideal conditions

-static

stand still or prevent change or growth

sepsis

growth of microbes in blood or other tissues

-cide

killing

decontamination

Mechanical removal of most microbes from living or inanimate objects

disinfection

destruction of most microbes on inanimate surfaces

degermination

reduction of the number of microbes on the human skin

antisepsis

destruction of most microbes on living surfaces

sanitation

mechanical removal of microbes to reduce contamination to safe levels

sterilization

destruction of all microbial life on inanimate surfaces

Rank the following from most resistant microbial forms to the least resistant microbial forms to chemical control methods

Least resistance - bacterial vegetative cells

Moderate resistance - naked viruses

Highest resistance- endospores

Moist heat

Heat with water; examples include boiling

dry heat

use of just heat; examples include: baking and incineration

dessication

air-drying of microbes

ionizing radiation

Use of gamma rays, x rays, and cathode rays to damage proteins in microbes

cold method

Microstatic control of microbes; used to preserve cultures; refrigeration

autoclave

use of steam under pressure

pasteurization

disinfection of beverages

non-ionizing radiation

use of ultraviolet rays to damage DNA and restrict replication

filtration

Decontamination technique that removes a particular kind of microbe when passing liquid or gas through a porous material

aldehydes

disrupting proteins by replacing hydrogen with an aldehyde group; germicide; examples include formaldehyde and gluteraldehyde

phenols

Disrupts cell wall, cell membrane, and affects proteins and enzymes; microbicidal; examples include triclosan and lysol

surfactants

binds to proteins on the cell membrane and disrupts the lipids in the cell membrane; examples includes detergents

hydrogen peroxide

damage to lipids in the cell membrane and form hydroxyl free radicals

alcohols

causes dehydration and denatures proteins; microbistatic; examples include ethanol

halogens

denatures proteins and enzymes; examples include iodine and chlorine

gaseous sterilants and disinfectants

blocks enzymatic function and DNA repair/replication; examples include ethylene oxide and chlorine dioxide

heavy metals

binds to function groups on proteins and render the proteins inactive; examples include silver and mercury