Answer:
In this case, it is likely that the polypeptide chain assumed an alpha helix configuration because the lipid bilayer did not have beta-barrel proteins.
Explanation:
A polypeptide chain is naturally polar, however, a lipid bilayer is naturally non-polar. This makes it difficult and even prevents the polypeptide chain from crossing a lipid bilayer, since the composition of these two elements does not allow them to mix. In that case, the polypeptide chain has two options to take to successfully cross the lipid bilayer.
The first option that the polypeptide chain has is to allow the creation of twisted beta sheets in the shape of a closed barrel in its structure. This only works if the lipid bilayer has beta barrel proteins in its composition to act as a transport channel for the polypeptide chain. However, few lipid layers have this protein.
Most likely, the polypeptide chain assumes an alpha helix conformation to cross lipid bilayers that do not have beta-barrel proteins. By assuming the beta conformation, the polypeptide chain reinforces the hydrogen bonds present in its composition, allowing it to cross the lipid bilayer without having its conformation and structure disassembled.
It is an example of directional selection.
The different kinds of natural selection can influence the distribution of phenotypes within a population. In stabilizing selection, an average phenotype is preferred.
In directional selection, a modification in the surrounding changes the spectrum of the observed phenotypes, and in diversifying selection the extreme values for a trait are preferred over the transitional values. This kind of selection usually pushes speciation.
The directional selection, in the field of population genetics, refers to a mode of natural selection in which an extreme phenotype is preferred over other phenotypes, making the allele frequency to change with time in the orientation of that phenotype.
Secondary structure of protein.
in seconday structure, the polypeptide chain is spirally arranged in linear form.
Teriary structure of protein
In tertiary structure the polypeptide chain is arranged in three dimension.
Quaternary structure of protein
In this structure more than one polypeptide chain are arranged in three dimension forming a globular shape.
Answer:
Isolating a single bacterium species is the first step in identifying the bacteria possibly responsible for a disease process.
Explanation:
