Echinoderms, like chordates, are deuterostomes and are therefore thought to be the most closely related of the major phyla to the chordates
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.
B is the answer for your question
Answer:
Heart attack
Explanation:
Heart attack is the death of a part of heart muscles and severe pain that causes heart constriction having pain in the chest which spread to the left shoulder and down the arm thereby causing the feeling of pressure in the chest.
This is caused when a blood clots blocks blood flow to the heart thereby leading makes the tissue to loss oxygen and die.
The symptom of heart attack are;
pain in the chest, neck, back or arms, fatigue, lightheadedness, abnormal heartbeat and anxiety, nausea.
Treatment ranges from surgery, medication , rehabilitation e.t.c.
