Which gas is found in the form of proteins in plants and animals?

Which among the following $\alpha$-amino acids does $NOT$ have a chiral carbon atom?

In the primary structure of proteins,the amino acids are interconnected by-

Which of the following statements is not correct?

Explain the types of protein structures based on the provided image.

Assertion $(A)$: The denaturation of proteins can destroy all $1^{\circ}, 2^{\circ}$ and $3^{\circ}$ protein structures.
Reason $(R)$: Curdling of milk is due to denaturation of proteins.
The correct option among the following is