Which of the following contributes to the double helical structure of DNA ?
Hydrogen bond
Covalent bond
Disulphide bond
van der Waals' force
A.
Hydrogen bond
According to double helical model of DNA (proposed by Watson and Crick), DNA molecule contains two deoxyribonuclide chains which are spirally coiled around each other on a common axis. These two chains are held together by the formation of hydrogen bonds,
A tripeptide is written as glycine-alanine -glycine. The correct structure of the tripeptide is