Allosteric Properties

24問 • 1年前

問題一覧

Graphically represented in an oxyhemoglobin dissociation curve

Oxygen Dissociation

Which describes the relationship between Oxygen Content (% saturation) and partial pressure of Oxygen; sigmoid shape is due to cooperative binding of Oxygen

oxyhemoglobin dissociation curve

partial pressure of Oxygen required to produce half saturation of hemoglobin, when the deoxyhemoglobin concentration equals the oxyhemoglobin concentration at a constant pH and temperature.

P50

Hb has a very low affinity for Oxygen

PO2 < 20 mmHg

Affinity for oxygen increases substantially as represented by a steep slope in the tissue

PO2 = 20-60 mmHg

curve flattens rapidly toward the area of 100% saturation, indicating an almost complete saturation of Hb with Oxygen.

PO2 > 60 mmHg

PO2 of less than 27 mmHg, increased Oxygen Affinity; associated with a decrease in body temperature, release of 2,3-BPG and CO2 concentration and an increase in blood pH.

Shift to the Left

PO2 of less than 27 mmHg, increased Oxygen Affinity; associated with a decrease in body temperature, release of 2,3-BPG and CO2 concentration and an increase in blood pH.

Shift to the Left

PO2 of more than 27mmHg, decreased Oxygen Affinity and increase Oxygen release results from the conversion of HbO2 to Hb in the tissues an increase in CO2 concentration increased 2,3-BPG binding, lower blood pH.

Shift to the Right

A shift in the curve because of a change in pH (or hydrogen ion concentration)

 Bohr Effect

It facilitates the ability of hemoglobin to exchange oxygen and carbon dioxide (CO2).

Bohr Effect

Describes the relationship between pH and O2 affinity Seen as a shift to the right of the HbO2 dissociation curve caused by decrease pH (↓pH=↓O2 affinity)

Bohr Effect

Leads to a decrease in O2 affinity caused by the binding of H+ ions and CO2

Acidosis

Shifting of dissociation curve or change in the Hb affinity for O2 resulting from variations in CO2 concentration

Haldane Effect

↑ CO2 concentration will shift to the right (vice versa). ↑ CO2 in the tissues, therefore O2 affinity is ↓.

Haldane Effect

That partly explains by the Bohr Effect, because CO2, aside from H+ ions stabilize the HbO2. While in the pulmonary capillaries, CO2 level is ↓ because it is being expired/exhaled in the lungs, so affinity of Hb is ↑.

Haldane Effect

The primary substance that regulates Hb for O2 affinity. Combines with the beta chains of deoxyhemoglobin and diminishes the molecule’s affinity for O2

2,3-bisphosphoglycerate

low O2 affinity state

Tense form

high O2 affinity state

relaxed form

One_______ molecule is enough to prevent the binding of O2 to the heme pockets of Hb; 1 Hb molecule can bind up to 4 molecules of O2,

2,3 DPG

• Hb transports approximately one fourth of the total carbon dioxide exchanged by erythrocytes in respiration through the direct transport mechanism  • Deoxyhemoglobin directly binds with CO2 which reacts with uncharged amino groups of the globin chains to form negatively charged carbamino hemoglobin.

Carbon Dioxide Transport

The carbon dioxide transport emphasized the ability of Hb to transport CO2; involves the formation of? Which is the binding of CO2 to Hb; Accounts for 1⁄4 of total CO2 transport

Carboxyhemoglobin

In venous blood, the carbon dioxide diffuses into the RBCs and combines with water to form carbonic acid (H2CO3).  This reaction is facilitated by the RBC enzyme?

Carbonic anhydrase

Dysfunctional Hgb that are unable to transport O2.  Exposure to environmental chemicals, gas, or drugs.

Dyshemoglobins

Introduction to Histology

Almira Coleen · 28問 · 1年前

Introduction to Histology