Control of Microbial Growth Flashcards
How do aldehydes work and what is an example?
alkylating groups in proteins and other important cellular molecules, formeldyhide.
What pore sizes would be best for filtering solutions known to contain bacteria but not viruses?
.22 um
define aseptic technique
techniques that reduce significant contamination
What macromolecules are affected by radiation?
DNA
Define disinfection
removal of non endopsore forming pathogens from a non living surface using physical or chemical methods
Define commercial sterilization
destruction of all pathogenic endospores but not necessarily all microbes
define sanitization
reduction of microbes to a safe level to meet public health standards
How do heavy metals work and what is an example?
Combine with amino acids that contain sulfhydryl groups, silver nitrate.
Give examples of ionizing and nonionizing radiation.
ionizing: gamma/xrays used in food
non ionizing- UV/visible light, used in hospitals on hard surfaces
How does ozone work and what is an example?
high voltage passed through water to kill microbes.
How do oxidizing agents work and what is an example?
oxidize proteins
hydrogen peroxide antiseptic, benzoyl peroxide good for wounds and acne, peracetic acid good against all bacteria and viruses
What is HTST?
high temperature short time pasteurization
How does ethylene oxide work and what are examples?
denatures proteins by alkylation of some amino acids, used for food and soft items
Why are microwaves not good at sterilizing solid foods?
their waves are not powerful enough to disrupt the DNA. Instead steam produced can kill cells.
How do phenols and phenolics work and what is an example?
work by injuring the plasma membrane, lysol.