Question

The most common methods of microbial control might be hand washing and cooking of food.

a. Explain, in detail, how soap and water disrupt a membrane at the molecular level.

b. Explain how heat disrupts proteins, referencing the different levels of protein structure.

c. Design an imaginary device that inactivates non-enveloped human viruses. What does the device do to the virus?

Answer 1

a)                                      

• Soap is made of pin-shaped molecules, each of which has a hydrophilic head (it readily bonds with water) and a hydrophobic tail, which shuns water and prefer to link up with oils and fats. These molecules , when suspended in water, alternately float about as solitary units, interact with other molecules in the solution assemble themselves into little bubbles called micelles, with heads pointing outward and tail tucked inside.

                                            Some bacteria and viruses (mostly microbes) have lipid-membranes that resemble double-layered micells with two bands of hydrophobic tails sandwiched between two rings of hydrophilic heads. These membranes are studded with important proteins that allow viruses to infect cells and perform vital tasks that keep bacteria alive. Pathogens wrapped in lipid membranes include coronaviruses, HIV ,Ebola, Zika, dengue, and several other microbes.

                                           When you wash your hands with soap and water, you surround any micro organisms on your skin with soap molecules. The hydrophobic tails of the free-floating soap molecules attempt to evade water; in the process, they wedge themselves into the lipid envelopes of certain microbes and viruses, prying them apart. In short " they act like crowbars and destabilize the whole system" .

                 For example : In coronaviruses

                             

b)                            

• Denaturation is the process in which proteins or nucleic acids lose the quartenary structure, teritiary structure present in their native sites , by the application of some external stress like temperature and others. Protein denaturation is also a consequence of cell death. Denatured proteins can exhibit a wide range of characteristics, from conformational change and loss of solubility to aggregation due to exposure of hydrophobic groups.

                                

                 

                      Protein folding consists of a balance between a substantial amount of weak intra-molecular interactions within a protein and protein-solvent interactions. As a result , this process is heavily reliant on environmental state that the protein resides in. These environmental conditions include temperature, salinity , pressure and others too. Consequently any exposure to extreme stresses can disrupt a protein's interaction between their bonds and lead to denaturation.

• In secondary protein , denaturation causes the bonds like alpha-helix/beta-plated structures to breakdown and lead to severe changes in the environmental chemisrty they residue in.
• In tertiary structure , denaturation causes the bonds like hydrogen disultide bonds structures to breakdown and lead to failure of several biological activities of proteins.
• In quartenary structure , denaturation causes heavily coiled structures evolved from tertiary structure to failure and leads to malfunction of activity done by the structure

c)                    Inactivation of non-enveloped viruses can be done by an electrically charged disinfectant containing meso-structure nanoparticles via modification of it's genome.

•                   Methods :
•                                           The inactivation effects of CAC-717 against various micro-organisms ( non-enveloped virus, eg; Feline calcivirus (FCV)) were investigating by comparing the viral titer of the medium tissue culture infectious dose (TCID50) and the D value (estimated treatment time required to reduce the number of micro-organisms by 90%) .Furthermore , the effects of CAC-717 on viral and bacterial genomic RNA/DNA were examined using Polymerase chain reaction(PCR).

•                    Results   :
•                                             Treatment of an equal volume of CAC-717 with cell lysate infected with a non-enveloped virus, Feline calcivirus (FCV), reduced the TCID50 , Viral titer dropped below the detection limit after 2 minutes of treatment.

                                    The D value of FCV was 0.256 min and endpoint D value was 0.341 minutes . In addition , PCR showed the inhibition of nucleic acid amplification of the RNA of FCV respectively.

                  Conclusions : Penultimately , it suggests that CAC-717 inactivates viruses by modifying the viral nucleic acids.