Which is an optically inactive amino acid?

Identify the $N$-terminal and $C$-terminal $\alpha$-amino acids respectively in the following polypeptide fragment: $Ala-Gly-Ser-Tyr-Gly$.

Which of the following is $NOT$ a globular protein?

Which of the following compounds is an amino acid?

Out of the following,which type of interaction is responsible for the stabilisation of $\alpha$-helix structure of proteins?

The most important energy source in every living cell is $......$.