It is known as projecting. Data retrieval means obtaining data from a database management system such as ODBMS. In this case, it is considered that data is represented in a structured way, and there is no ambiguity in data. In order to retrieve the desired data the user present a set of criteria by a query. Project management information system are system tools and techniques used in project management to deliver information. Project managers use the techniques and tools to collect, combine and distribute information through electronic manual means.
Excitation-contraction coupling refers to the series of events that begins with the excitation of the sarcolemma in response to stimulation by a neurotransmitter, and results in the release of calcium ions from the sarcoplasmic reticulum.
Hence, option D is the 1st process that starts the excitation-contraction coupling.
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.
Because the earth is moving around the sun but the sun isn’t revolving around anything