Hemoglobin (hb) can be viewed as having two quaternary states, a low oxygen affinity state (t), and a high oxygen affinity state (r). which of the following statements about the binding of o2 by hb are true? upon binding a molecule of oxygen, hb undergoes a conformational change that makes the binding of subsequent o2 molecules more favored. the conformational change induced in hb upon binding oxygen is the result of a small movement (0.2 å) of the iron cation into the center of heme. site-directed mutagenesis studies have indicated that the cooperativity of o2 binding in hb is attributable to the movement of the f helix in hb. site-directed mutagenesis studies in which the proximal his residues of the f helix have been replaced by glycines have indicated the mutant protein still shows cooperativity of o2 binding.

Answer;

The statements that are True are;

Upon binding a molecule of oxygen, Hb undergoes a conformational change that makes the binding of subsequent O2 molecules easier. The conformational change induced in Hb upon binding oxygen is the result of a small movement (0.2 Å) of the iron cation in the center of heme.Site-directed mutagenesis studies have indicated that the cooperativity of O2 binding in Hb is attributable to the movement of the F helix in Hb.Explanation;Hemoglobin is a key pigment in the blood that transports oxygen gas to all the tissues in the body. It is made up of two types of chains; that is two alpha chains and two beta chains.  in its deoxygenated state hemoglobin has a low affinity for oxygen compared to myoglobin. When oxygen is bound to the first subunit of hemoglobin it leads to subtle changes to the quaternary structure of the protein. This in turn makes it easier for a subsequent molecule of oxygen to bind to the next subunit.

For cyclohexane compounds drawn in a chair conformation:   -axial bonds are vertical  -equatorial bonds are parallel to two bonds within the ring.  thus, as i assume the chair conformation is drawn:   -the x group is in an axial position, as are the five other vertical bonds.  -three axial bonds are on the top face of the ring  -the other three axial bonds are on the bottom face  the position of the second substituent on each ring carbon is equatorial.  gauche groups must be on an adjacent carbon such as carbon 6 and carbon 2, and also gauche groups are rotated by 60 degrees relative to each other.  drawing the newman projections for c1–c2 and c1–c6 aids in visualizing the groups that are gauche to the y group on c1.  click this link and watch some academic videos that may you more understand the topic