BIOLOGY. 2. : BIOLOGY. 2. Biology. Student’s Name. Inst

Running head: BIOLOGY 1
Biology
Student’s Name
Institutional Affiliation

BIOLOGY 2
Biology
Question one.
A protein domain is a particular unit of protein that can evolves and functions
independently. The domains are considered the building blocks of a protein. Each unit usually
forms a compact structure comprising of three dimensions that can similarly stand on their own
(Ingolfsson & Yona, 2008). Thus, a single domain can present itself in a variety of diverse
proteins.
Question two.
The alpha helix together with the beta sheet are found in the secondary level of the
protein structure. The two structures are similar in that their shapes are maintained by hydrogen
bonds. The development of the bonds of hydrogen occurs between the components of carbonyl O
and amino H of two different amino acids (Ezkurdia & Tress, 2011). The two structures differ in
that alpha helix involves the hydrogen bonding of a carbonyl of a particular amino acid to the
amino H of another amino acid while beta sheet involves at least two parts of a polypeptide chain
lying on adjacent to each other.
Question three
Hydrogen bonds are used to entirely determine the secondary protein structure whereas in
the tertiary protein structure, the hydrogen bonds need to interact with others such as the
disulphide bonds so as to form the structure (Ezkurdia & Tress, 2011). That is to say, the
hydrogen bonds found in the secondary protein structure are much stronger than those found in
the tertiary protein structure.
Question four