A noncovalent bond between an electronegative atom (commonly oxygen or nitrogen) and a hydrogen atom covalently bonded to another electronegative atom. Particularly important in stabilizing the three-dimensional structure of proteins and formation of base pair s in nucleic acids.
Introduction[edit] The respiratory system serves three principal purposes in the human body: gaseous exchange; sound production; and assistance in compression of the abdomen. It can be divided into two structural divisions, upper and lower, as well as two functional divisions, conducting and respiratory.
In humans the pharynx is part of the digestive system and also of the conducting zone of the respiratory system. The conducting zone also includes the nose, larynx, trachea, bronchi, and bronchioles, and their function is to filter, warm, and moisten air and conduct it into the lungs.he conducting zone also includes the nose, larynx, trachea, bronchi, and bronchioles, and their function is to filter, warm, and moisten air and conduct it into the lungs.