In sicklecell disease as a result of a single amino acid cha

In sickle-cell disease, as a result of a single amino acid change, the mutant hemoglobin tetramers associate with each other and assemble into large fibers. Based on this information alone, we can conclude that sickle-cell hemoglobin exhibits:

altered primary structure and altered quaternary structure; the secondary and tertiary structures may or may not be altered.

(Please which option listed above is the right answer)

Solution

Hi,

The answer to above question is option is: \" altered primary structure and altered quaternary structure; the secondary and tertiary structures may or may not be altered.\"

The protein structure has been divide into 4 parts.

a) Primary structure: It is basically the amino acid sequence. Each protein has unique amino acid sequence and small change in amino acid sequence alters the primary structure. In the case of sickle cell disease, the amino acid has changed , and hence the primary structure of the protein molecule changes.

b). Secondary structure: It is the basic folding of the amino acid chain, which results from intramolecular and intermolecular hydrogen bonding of amide groups. Ex; Alpha helix and Beta sheets. In the above case, this may o may not have changed as there is no definitive way to know this.

c) Tertiary structure: Most proteins\' tertiary structures are combinations of a helices, b sheets, and loops and turns. Each protein has unique three dimensional structure, folded in a specific manner sometimes called as domains. In our case, since it depdens on secondary structure, it may or may not have changed. ( hemoglobin monomers )

d) Quaternary structure: It is the association of multiple individual protein chains into a single protein with multiple subunits. The arrangement of the subunits gives rise to a stable structure. Like in our case a hemoglobin tetramers associate with each other and assemble into large fibers. This has changed the original structure and thus we say the quaternary structure has changed.

I hope this answers the question.