Normal hemoglobin is a tetramer, consisting of two molecules of β hemoglobin and two molecules of α hemoglobin. 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
A) altered primary structure.
B) altered secondary structure.
C) altered tertiary structure.
D) altered quaternary structure.
E) altered primary structure and altered quaternary structure; the secondary and tertiary structures may or may not be altered.
Structure of chlorophyll molecules in chloroplasts of plants
An ECG strip showing a normal sinus rhythm with the P wave, QRS complex, and T wave identified.
Molecular asymmetry: chiral and achiral molecules
the fatty acid molecules expose the smallest possible hydrophobic surface area
Creating Complex Molecules
Three types of “end feel” in normal joints.