The non-essential amino acid among the following is

Which one of the following is an amino acid?

The incorrect statement about denaturation of proteins is

Which of the following has amide links?

Protein found in a biological system with a unique three-dimensional structure and biological activity is called a native protein. When a protein in its native form is subjected to a physical change like a change in temperature or a chemical change like a change in $pH$,denaturation of proteins takes place. Explain the cause.

The helical structure of protein is stabilised by