Hemoglobinopathies and Oxygen Binding

These flashcards cover key concepts related to hemoglobin, hemoglobinopathies, and the molecular biology of oxygen binding.

Hemoglobinopathies

Genetic disorders caused by abnormal hemoglobin, affecting its structure and function.

Heterotropic effectors

Molecules that influence metabolic pathways by binding to proteins and altering their activity.

2,3-BPG

A molecule that binds to hemoglobin and decreases its oxygen affinity, promoting oxygen delivery.

Sigmoidal curve

A characteristic shape of the hemoglobin oxygen binding curve, indicating cooperative binding.

Hyperbolic curve

The shape of the myoglobin oxygen binding curve, which indicates a single binding site and a non-cooperative process.

Fractional saturation

The ratio of occupied binding sites to total binding sites on hemoglobin or myoglobin.

pH effect on oxygen affinity

Lower pH (more protons) decreases oxygen affinity of hemoglobin, promoting oxygen release.

Carbon dioxide's role in hemoglobin function

CO2 contributes to the Bohr effect by increasing proton concentration, which stabilizes the T state of hemoglobin.

T state (tense state)

The conformation of deoxyhemoglobin that has low affinity for oxygen.

R state (relaxed state)

The conformation of oxyhemoglobin that has high affinity for oxygen.

Sickle cell anemia

A hemoglobinopathy caused by a single amino acid substitution in the beta chain of hemoglobin.

Fetal hemoglobin (HbF)

Hemoglobin type that binds oxygen more tightly than adult hemoglobin (HbA), facilitating oxygen transfer from mother to fetus.

Alpha and beta globin genes

Genes that encode the two types of polypeptide chains that make up hemoglobin.

Oxidation of ferrous ion

Conversion of Fe2+ to Fe3+, leading to loss of oxygen binding capacity in hemoglobin.

Gene expression adaptations to altitude

Increased production of 2,3-BPG to enhance oxygen delivery in low-oxygen environments.

Salt bridges in hemoglobin

Ionic interactions that stabilize the T state of hemoglobin and facilitate oxygen release.

Proline's role in hemoglobin stability

Proline can disrupt alpha helical structures, affecting the stability and function of hemoglobin.