b. testing the hypothesis
If, in a peptide chain, there were 85 amino acids each joined by peptide bonds, there would only be 1 N-terminus group that would be present. The N-terminus group is always the start of the chain of a amino acid chain or a protein or a polypeptide. It refers to the free amine group present that is located at the end part of the chain. So, that no matter how many amino acids in a chain there would always be only one N-terminus group.
<span>D. protons
</span><span>
AND NEUTRONS
The atoms in a compound are held together by a chemical bond. The chemical bonds can be either covalent bonds or ionic bonds. Both the bonds are considered very strong bonds. These bonds are mainly formed by sharing of electrons or in the case when one of the elements making the compound donates electron to the other element. The nucleus of each atom attracts to form a strong bond. This property of attraction between the nucleus of the atoms actually helps in forming the chemical bonds. </span>
The correct option is B.
Phenophtalein is an indicator that is usually used in acid base titration experiments. Indicators are substances that undergo distinct, observable changes when the pH of their solutions change. Indicators exhibit changing of colors depending on the pH of the solution in which they are found. They are usually weak bases and acid which are capable of partial dissociation and formation of ions when dissolved in water. There are different types of indicator and phenophtalein is one of them. Phenophtalein is colorless in acidic solution and pink in basic solutions.
