Question

1a)for each of the 7 groups of chemical aganets(aldehyde, quaternary ammonium compounds, heavy metals, sterilizing gases, halogens,phenolics, and alcohols) identify theechanism of action and determine if the agent is capable of sterilizing or only disinfecting.
b) for the table below, for each relevant (ignore fungi) group of organisms, discuss what cellular characteristics or reasons the organism falls into that place on the ability to be killed scale.

Answer 1

1. A)

Aldehydes: The protein-protein cross linkages severely disrupt the abilities of the bacteria to propagate and to function. They can sterilising or disinfecting.

Quaternary ammonium compounds:  The bactericidal action of the quaternaries has been attributed to the inactivation of energy-producing enzymes, denaturation of essential cell proteins, and disruption of the cell membrane. It is a disinfectant.

Heavy metals: kill microbes by binding to proteins, thus inhibiting enzymatic activity. Ions of heavy metals bind to sulfur-containing amino acids strongly and bioaccumulate within cells, allowing these metals to reach high localized concentrations. Heavy metals are disinfectants.

Sterilising gases:  It reacts with protoplasm, DNA, and proteins and deactivates enzymes and other biologically important components of a living organism.

Halogens: are disinfectants. Chlorine destroys microorganisms by chlorinating the lipid protein substance in the bacterial cell wall to form toxic chloro compounds and induces the leakage of macromolecules from the cells.

Phenolics: Phenolcs accumulates on the surface of the bacterial cell wall and damage it. It is a disinfectant not used much now a days due to its carcinogenicity.

Alcohol: A disinfectant kill microbes by denaturing proteins

B)

Low-level disinfectants kill most vegetative bacteria, some fungi, and some viruses such as Staphylococcus species, Pseudomonas species, Salmonella species, HIV virus, herpes simplex virus, hepatitis B, hepatitis C, and many common cold viruses. There are hundreds of items that are routinely sterilized or disinfected. Similarly, the composition of the cell membrane differs from one microorganism to another. This is why different microorganisms differ in their responses to disinfectants. Gram-positive bacteria are more susceptible to disinfectants whereas spores forming organisms are more resistant to disinfectants.