How much does the binding affinity of carbon monoxide (CO) for free heme molecules exceed that of oxygen (O2)?
Explanation
The intrinsic chemical properties of the heme group lead to an extremely high affinity for carbon monoxide, more than 20,000 times that for oxygen. The protein environment in myoglobin and hemoglobin is crucial for reducing this affinity difference to prevent poisoning by endogenous CO.
Other questions
What is the primary role of the coordinated nitrogen atoms in the porphyrin ring of the heme group in oxygen-binding proteins?
In the context of protein-ligand interactions, what is the relationship between the association constant (Ka) and the dissociation constant (Kd)?
What is the P50 value for oxygen binding to myoglobin, as indicated by the graphical representation of ligand binding?
What structural change occurs in the porphyrin of hemoglobin's heme group when it is in the T state, according to the model proposed by Max Perutz?
In the MWC (concerted) model for cooperative binding in an allosteric protein, what is a key assumption about the conformational states of the subunits?
What is the effect of 2,3-bisphosphoglycerate (BPG) on hemoglobin's affinity for oxygen?
What is the specific amino acid substitution in the beta chains of hemoglobin that leads to sickle-cell anemia?
In the humoral immune system, what type of cells are responsible for producing and secreting soluble proteins called antibodies?
What is the molecular weight of an Immunoglobulin G (IgG) molecule, which is composed of two heavy chains and two light chains?
Which immunoglobulin class is found as a cross-linked pentamer and is the first antibody to be made by B lymphocytes in a primary immune response?
The contractile force of muscle is generated by the interaction of which two proteins?
Myosin, with a molecular weight of approximately 520,000, is composed of how many subunits?
What is the entire contractile unit of a muscle fiber, consisting of bundles of thick filaments interleaved with bundles of thin filaments, called?
In the four-step cycle of muscle contraction, what event directly triggers the 'power stroke'?
What is the molecular basis of the genetic disease sickle-cell anemia?
According to the Hill equation, what does a Hill coefficient (nH) of less than 1 indicate about ligand binding?
Which of the following molecules binds to free heme more than 20,000 times better than oxygen, but only about 200 times better when the heme is bound in myoglobin?
In the immune system, what is the term for a small molecule that is not antigenic by itself but can elicit an immune response when covalently attached to a large protein?
What is the primary function of the protein titin in skeletal muscle?
The human immune system is capable of producing how many different antibodies, each with a distinct binding specificity?
What is the approximate molecular weight of the muscle protein actin in its monomeric G-actin form?
When a protein binds to a ligand, the structural adaptation that occurs between the protein and ligand, permitting tighter binding, is known as what?
In hemoglobin, the transition from the T state to the R state involves a significant conformational change primarily at which subunit interface?
What is the role of the protein troponin in muscle contraction?