List the ways carbon dioxide can be transported in the blood
Dissolved as CO2 in the plasma, combined with haemoglobin as carbaminohaemoglobin and as hydrogencarbonate ions in the plasma
Describe how carbon dioxide is converted to hydrogencarbonate ions
CO2 enters the red blood cell and is combined with water to form carbonic acid. The enzyme carbonic anhydrase ensures that this occurs. The carbonic acid dissociated to hydrogen ions and hydrogencarbonate ions
Explain the need for the chloride shift
The hydrogencarbonate ions are negatively charged. They diffuse out of the red blood cell, leaving it with a positive charge. Chloride ions are moved into the red blood cell to neutralise this charge
Explain how the presence of carbon dioxide can reduce the affinity of haemoglobin for oxygen
The hydrogen ions released from the dissociation of the carbonic acid compete with oxygen for a space on the haemoglobin molecule. If there are more hydrogen ions then more oxygen will be released from the haemoglobin
Describe how haemoglobin can supply more oxygen to actively respiring tissues than to those who have a lower level of respiration
Actively respiring tissue release more CO2. This forms more carbonic acid so more hydrogen ions are formed. More hydrogen ions will cause more oxygen to be released from the haemoglobin
Where is carbon dioxide released from?
Respiring tissues
How is carbon dioxide transported in the blood?
5% is directly dissolved in the plasma, 10% is combined directly with haemoglobin to form a compound called carbaminohaemoglobin 85% is transported in the form of hydrogen ions
What is it called when carbon dioxide combines with haemoglobin?
Carbaminohaemoglobin
How are hydrogencarbonate ions formed?
As carbon dioxide diffuses into the blood, some of it enters the erythrocytes. This is catalysed by the enzyme carbonic anhydrase. This carbonic acid dissociates to release hydrogen ions (H+) and hydrogencarbonate ions (HCO3-). The hydrogencarbonate ions diffuse out of the erythrocytes into the plasma. The charge inside the erythrocyte is maintained by the movement of chloride ions (Cl-) from the plasma into the erythrocyte. This is called chloride shift. The hydrogen ions could cause the contents of the erythrocyte to become very acidic. To prevent this, the hydrogen ions are taken up by haemoglobin to produce haemoglobinic acid. The haemoglobin is acts as a buffer.
Hydrogencarbonate ions symbol
HCO3-
Hydrogen ions symbol
H+
As carbon dioxide diffuses into the blood, some of it enters the erythrocytes. This is catalysed by the enzyme carbonic anhydrase.
CO2 + H2O --> H2CO3
CO2 + H2O --> H2CO3
As carbon dioxide diffuses into the blood, some of it enters the erythrocytes. This is catalysed by the enzyme carbonic anhydrase.
Correct this equation?CO + H2O --> H2CO3
CO2 + H2O --> H2CO3
H2CO3 --> HCO3- + H+
This carbonic acis dissociates to release hydrogen ions (H+) and hydrogencarbonate ions (HCO3-).
This carbonic acis dissociates to release hydrogen ions (H+) and hydrogencarbonate ions (HCO3-).
H2CO3 --> HCO3- + H+
As _______ _______ diffuses into the _____, some of it enters the e___________. This is __________ by the enzyme ________ __________. This carbonic acid dissociates to release ________ ions (H+) and _________________ ions (HCO3-). The _________________ ions diffuse out of the ____________into the ______. The charge inside the __________ is maintained by the movement of ________ ions (Cl-) from the _______ into the ___________. This is called ________ _____. The _________ ions could cause the ________ of the___________to become very ______. To prevent this, the hydrogen ions are taken up by___________to produce ____________ acid. The haemoglobin acts as a ______.
As carbon dioxide diffuses into the blood, some of it enters the erythrocytes. This is catalysed by the enzyme carbonic anhydrase. This carbonic acid dissociates to release hydrogen ions (H+) and hydrogencarbonate ions (HCO3-). The hydrogencarbonate ions diffuse out of the erythrocytes into the plasma. The charge inside the erythrocyte is maintained by the movement of chloride ions (Cl-) from the plasma into the erythrocyte. This is called chloride shift. The hydrogen ions could cause the contents of the erythrocyte to become very acidic. To prevent this, the hydrogen ions are taken up by haemoglobin to produce haemoglobinic acid. The haemoglobin is acts as a buffer.
What is a buffer?
A compound that can maintain a constant PH
How is oxygen released?
In the body, tissue cells need oxygen for aerobic respiration. Therefore the oxyhaemoglobin must be able to release the oxygen. This is called dissociation
Releasing oxygen
As the blood enters the respiring tissues, the haemoglobin is carrying oxygen in the form of oxyhaemoglobin. The oxygen tension of the respiring tissues is lower than that in the lungs because oxygen has been used in respiration. As a result, the oxyhaemoglobin begins to dissociate and releases oxygen to the tissues
As the _____ enters the _________ tissues, the ___________ is carrying ______ in the form of _____________. The oxygen tension of the __________ tissues is _____ than that in the _____ because _______ has been used in ___________. As a result, the _____________ begins to ___________nnd ________ oxygen to the tissues.
As the blood enters the respiring tissues, the haemoglobin is carrying oxygen in the form of oxyhaemoglobin. The oxygen tension of the respiring tissues is lower than that in the lungs because oxygen has been used in respiration. As a result, the oxyhaemoglobin begins to dissociate and releases oxygen to the tissues.
The _________ ions released from the _____________ of _________ acid compete for the space taken up by ______ on the ___________ molecule. So when carbon dioxide is ________, the _________ ions displace the _______ on the ___________. As a result, the ______________ releases more ______ to the ______. When tissues are _________ more, there will be more ______ _______. As a result there will be more ________ ions produced in the ___________. This makes _____________ release more _______. This is the ____ effect. At any particular ______ tension, the _____________ releases more ______ when more carbon dioxide is _______. So when more carbon dioxide is _______, haemoglobin is ____ _________ with oxygen. This makes the ______________ dissocation curve_____ downwards and to the _____(Bohr Shift). The ____ effect results in _______ being more readily released where more ______ dioxide is produced from __________. This is just what the _______ need for ______ respiration to continue.
The hydrogen ions released from the dissociation of carbonic acid compete for the space taken up by oxygen on the haemoglobin molecule. So when carbon dioxide is present, the hydrogen ions displace the oxygen on the haemoglobin. As a result, the oxyhaemoglobin releases more oxygen to the tissue. When tissues are respiring more, there will be more carbon dioxide. As a result there will be more hydrogen ions produced in the red blood cell. This makes oxyhaemoglobin release more oxygen. This is the Bohr effect. At any particular oxygen tension, the oxyhaemoglobin releases more oxygen when more carbon dioxide is present. So when more carbon dioxide is present, haemoglobin is less saturated with oxygen. This makes the oxyhaemoglobin dissocation curve shift downwards and to the right (Bohr Shift). The bohr effect results in oxygen being more readily released where more carbon dioxide is produced from respiration. This is just what the muscles need for aerobic respiration to continue.
What do the hydrogen ions compete with oxygen for?
The space on the haemoglobin molecule
When do hydrogen ions displace the oxygen on the haemoglobin?
When carbon dioxide is present
What happens when hydrogen ions displace the oxygen on the haemoglobin molecule?
The oxyhaemoglobin releases more oxygen to the tissue
What happens to carbon dioxide levels when tissues are respiring?
They increase
What happens when carbon dioxide levels are increasing?
More hydrogen ions are produced in the red blood cell
What happens to the oxyhaemoglobin when carbon dioxide levels increase
The oxyhaemoglobin releases more oxygen
What happens regarding the haemoglobin when more carbon dioxide levels are present?
Haemoglobin is less saturated with oxygen
What happens when the haemoglobin is less saturated with oxygen?
The oxyhaemoglobin dissociation curve shift downwards and to the right. Bohr shift
What does the Bohr effect result in?
More oxygen is readily released when more carbon dioxide is produced from respiration
What is Bohr shift?
The hydrogen ions released from the dissociation of carbonic acid compete for the space taken up by oxygen on the haemoglobin molecule. So when carbon dioxide is present, the hydrogen ions displace the oxygen on the haemoglobin. As a result, the oxyhaemoglobin releases more oxygen to the tissue. When tissues are respiring more, there will be more carbon dioxide. As a result there will be more hydrogen ions produced in the red blood cell. This makes oxyhaemoglobin release more oxygen.
The h________ _____ released from the dissociation of ________ acid compete for the space taken up by ________ on the ___________ molecule. So when carbon dioxide is ________, the hydrogen ions _________ the oxygen on the ______________. As a result, the ________________ releases more _______ to the tissue. When ________ are respiring more, there will be more _______ dioxide. As a result there will be more __________ ions produced in the red blood cell. This makes _______________________ release more ________.
The hydrogen ions released from the dissociation of carbonic acid compete for the space taken up by oxygen on the haemoglobin molecule. So when carbon dioxide is present, the hydrogen ions displace the oxygen on the haemoglobin. As a result, the oxyhaemoglobin releases more oxygen to the tissue. When tissues are respiring more, there will be more carbon dioxide. As a result there will be more hydrogen ions produced in the red blood cell. This makes oxyhaemoglobin release more oxygen.