Adenine is the nitrogenous base that is attached to sugar to make adenosine nucleotides. How many total atoms in adenine (excluding the location in the ring attached to the sugar in nucleotides and nucleic acids) can act hydrogen-bond donors and acceptors

Four total atoms can act as hydrogen-bond donors and acceptors in adenine excluding the location in the ring attached to the sugar in nucleotides and nucleic acids.

Explanation:

Hydrogen bond donors are those H atoms covalently to an electronegative atom such as Nitrogen or Oxygen whereas Hydrogen bond acceptors are electronegative atoms such as nitrogen and oxygen with at least one lone pair of electrons.

Oxygen and nitrogen are electronegative atoms found in nitrogenous bases such as adenine and guanine. These electronegative oxygen and nitrogen atoms with free lone pairs of electrons serve as potential hydrogen bond acceptors.

Hydrogen atoms attached to these electronegative atoms have strong partial positive charge since the electrons shared between them are more on the electronegative atoms, thus, they are potential hydrogen bond donors.

In an adenine molecule, there are four total atoms that can act as hydrogen-bond donors and acceptors in adenine excluding the location in the ring attached to the sugar in nucleotides and nucleic acids.

In the attachment below, there are three nitrogen atoms that are potential hydrogen bond acceptors denoted by A, and one nitrogen atom donor denoted by D.

answer:

sequence 1- deletion

                  2- duplication

                  3- insertion

                  4- substitute

                  5- inversion