Protein Function - Myoglobin and Hemoglobin

These flashcards cover key vocabulary terms related to protein function, particularly focusing on myoglobin, hemoglobin, and their mechanisms.

Myoglobin

A monomeric protein that facilitates oxygen storage in peripheral tissue.

Hemoglobin

A tetrameric protein found in red blood cells that transports oxygen from lungs to the periphery.

Protein-Ligand Interaction

The reversible interaction between a protein and a molecule called a ligand that can regulate protein function.

Ligand

A molecule that binds to a specific site on a protein, often regulating the protein's function.

Binding Site

A specific region on a protein where a ligand binds, typically complementary to the ligand's shape and charge.

Induced Fit

A conformational change in a protein that occurs upon ligand binding, altering the protein's properties.

2,3 Bisphosphoglycerate (2,3 BPG)

A heterotropic allosteric inhibitor of hemoglobin that decreases its affinity for oxygen to promote release to tissues.

Allosteric Regulation

The regulation of a protein's function through the binding of molecules at sites other than the active site.

The Bohr Effect

The phenomenon where decreasing pH reduces hemoglobin's affinity for oxygen, promoting oxygen release to active tissues.

Fetal Hemoglobin (HbF)

A form of hemoglobin with a higher affinity for oxygen than adult hemoglobin, important for oxygen transfer from mother to fetus.

Quaternary Structure

The structure formed by the assembly of multiple polypeptide subunits in proteins like hemoglobin.

Carbaminohemoglobin

Hemoglobin that binds carbon dioxide at the N terminus of its chains, promoting oxygen release.

Sickle Cell Anemia

A genetic disease resulting from a single amino acid change in hemoglobin, causing red blood cells to deform and block blood flow.

Cooperativity

The phenomenon in which the binding of one molecule to a protein increases the likelihood of additional molecules binding.

Heme

An iron-containing prosthetic group that allows proteins like myoglobin and hemoglobin to bind oxygen.

Proximal Histidine

A histidine residue that coordinates the iron atom in heme, influencing its oxygen-binding ability.

Distal Histidine

A histidine that stabilizes the bound oxygen molecule in heme.