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WGU BIOCHEM Module 3
Myoglobin and Hemoglobin
______________ is a protein consisting of a single subunit that contains a heme group with an iron atom bound. the iron atom binds one molecule of oxygen | myoglobin |
_______________ is a tetramer protein containing two alpha and two beta global subunits. | hemoglobin |
hemoglobin has __________ structure, while myoglobin has only ______________ structure because it has only one subunit | quaternary, tertiary |
each subunit contains a heme molecule and an iron atom, allowing each hemoglobin protein to bind _____ molecules of oxygen | 4 |
hemoglobin structure is very sensitive to ____________ binding | oxygen |
oxygenated form | relaxed or "R" state |
deoxygenated form | tense or "T" state |
hemoglobin's function | oxygen transport |
# of subunits in myoglobin | 1 |
# of subunits in hemoglobin | 4 |
addition of ____________ alters the shape of the iron-heme complex, and therefore its absorption of light as indicated by its color change from dark purple to brilliant scarlet | porphyrin |
myoglobin binds oxygen reversibly in response to ____________________ | oxygen concentration |
myoglobin function | bind and store oxygen for muscles to use when blood oxygen is low |
bohr effect: at high ph hemoglobin has a _____ affinity for oxygen, while at low ph it has a _____ affinity for oxygen and tends to release it | high; low |
2,3-BPG binds to _____________ hemoglobin and stabilizes the _____ state of the protein | deoxygenated; T |
carbonic anhydrase is an enzyme which catalyzes the conversion of carbon dioxide to _____________________ ions | bicarbonate |
hemoglobin acts as a buffer and controls the ph of the blood by binding to __________ | H+ ions |
in locations where the ph is low, hemoglobin will begin the _______ state, allowing it to ________ oxygen more efficiently | T; release |
carbon ___________ decreases hemoglobin's affinity for oxygen, while carbon _______________ increases it | dioxide; monoxide |
hemoglobin binds to carbon monoxide with a __________ affinity than oxygen and stabilizes the _______ state | higher; R |
when hemoglobin changes from T to R, it has __________ affinity for oxygen | high |
when hemoglobin changes from R to T, it has ________ affinity for oxygen | low |
______________ refers to hemoglobin structural changes that increase its affinity for oxygen | cooperativity |
when oxygen concentration is high, heme shape is ______________. when oxygen concentration is low, heme shape is _______________ | planar; bent |
relative to the lungs, the ph in the peripheral tissues is ________ because ______________ | lower, the CO2 generated by metabolism is converted to bicarbonate, which releases protons (H+) |
when the H+ ion concentration increases, the ph of the solution ____________ | decreases |
myoglobin has a _______ affinity for oxygen compared to hemoglobin | higher |
________________ has a signmoidal curve, where as ______________ has a hyperbolic curve | hemoglobin; myoglobin |
which atom helps oxygen bind to hemoglobin | iron |
the T state is favored by ___________pH and induces the ___________ of oxygen | low; release |
relative to the peripheral tissues, the ph in the lungs is ___________ because __________________ | higher; the protons (H+) that were combined with hemoglobin quickly bind to bicarbonate to form CO2, and then is exhaled |
carbon monoxide binds to hemoglobin ______ times better than oxygen | 200 |
when the blood ph is low, the heme is in ___________ shape when the blood ph is high, the heme is in ____________ shape | bent; planar |