Transportation of oxygen and co2

I hope it may of any help to you! :)

1. To explain the mechanism of transportation of Oxygen & Carbon Di-oxide in the body.

2. OUTLINE To explore how O2 is transported in the blood. To explore how Co2 is transported in the blood. This will include understanding the Oxygen & Carbon Di-oxide dissociation curve.

3. Oxygen Transport

4. Oxygen Transport

5. Oxygen Transport

6. Oxygen Transport Haemoglobin molecules can transport up to four O2’s When 4 O2’s are bound to haemoglobin, it is 100% saturated, with fewer O2’s it is partially saturated. Oxygen binding occurs in response to the high partial pressure of Oxygen in the lungs Co-operative binding: haemoglobin’s affinity for O2 increases as its saturation increases.

7. Oxygen Transport Oxyhemoglobin Formation : Oxygen + Hb  Oxyhemoglobin (Reversible) In the lungs where the partial pressure of oxygen is high, the rxn proceeds to the right forming Oxyhemoglobin When oxygen binds to haemoglobin, it forms OXYHAEMOGLOBIN. In the tissues where the partial pressure of oxygen is low, the rxn reverses. OxyHb will release oxygen, forming again Hb (or properly said deoxyhemoglobin )

8. 11 Oxygen Capacity : The maximum quantity of oxygen that will combine chemically with the hemoglobin in a unit volume of blood Normal Value: 1.34 ml of O 2 per gm of Hb or 20 ml of O 2 per 100 ml of blood. Oxygen Content : how much oxygen is in the blood Oxygen Saturation : The percentage of all the available heme binding sites saturated with oxygen Basic Concepts:

9. The oxygen-hemoglobin dissociation curve: Haemoglobin saturation is determined by the partial pressure of oxygen. When these values are graphed they produce the Oxygen Disassociation Curve In the lungs the partial pressure is approximately 100mm Hg at this Partial Pressure haemoglobin has a high affinity to 02 and is 98% saturated. In the tissues of other organs a typical PO2 is 40 mmHg here haemoglobin has a lower affinity for O2 and releases some but not all of its O2 to the tissues. When haemoglobin leaves the tissues it is still 75% saturated.

10. The oxygen-hemoglobin dissociation curve: Haemoglobin Saturation at High Values Lungs at sea level: PO2 of 100mmHg haemoglobin is 98% SATURATED Lungs at high elevations: PO2 of 80mmHg, haemoglobin 95 % saturated Even though PO2 differs by 20 mmHg there is almost no difference in haemoglobin saturation. When the PO2 in the lungs declines below typical sea level values, haemoglobin still has a high affinity for O2 and remains almost fully saturated.

11. The oxygen-hemoglobin dissociation curve:

12. Factors Affecting Haemoglobin Saturation

13. Factors affecting Disassociation BLOOD TEMPERATURE increased blood temperature reduces haemoglobin affinity for O 2 hence more O 2 is delivered to warmed-up tissue

14. BLOOD Ph lowering of blood pH (making blood more acidic) caused by presence of H + ions from lactic acid or carbonic acid reduces affinity of Hb for O 2 and more O 2 is delivered to acidic sites which are working harder Factors affecting Disassociation

15. CARBON DIOXIDE CONCENTRATION The higher CO 2 concentration in tissue The less the affinity of Hb for O 2 So the harder the tissue is working, the more O 2 is released Factors affecting Disassociation

16. Bohr Effect Bohr Effect refers to the changes in the affinity of Hemoglobin for oxygen. It is represented by shifts in the Hb-O2 dissociation curve Three curves are shown with progressively decreasing oxygen affinity indicated by increasing P(50)

17. SHIFT to the RIGHT  Decreased affinity of Hb for Oxygen Increased delivery of Oxygen to tissues It is brought about by Increased partial pressure of Carbon Dioxide Lower pH (high [H+]) Increased temperature Ex : increased physical activity, high body temperature (hot weather as well), tissue hypoxia (lack of O2 in tissues)

18. SHIFT to the LEFT  Increased affinity of Hb for Oxygen Decreased delivery of Oxygen to tissues It is brought about by Decreased partial pressure of Carbon Dioxide Higher pH (low [H+]) Decreased temperature Ex : decreased physical activity, low body temperature (cold weather as well), satisfactory tissue oxygenation

19. Key Point Increased temperature and hydrogen ion (H + ) (pH) concentration in exercising muscle affect the oxygen dissociation curve, allowing more oxygen to be uploaded to supply the active muscles.

20. Carbon Dioxide Transport Method Percentage Dissolved in Plasma 7 - 10 % Chemically Bound to Hemoglobin in RBC’s 20 - 30 % As Bicarbonate Ion in Plasma 60 -70 %

21. Carbon Dioxide Transport

22. Carbon Dioxide Transport Carbaminohemoglobin Formation Carbon dioxide molecule reversibly attaches to an amino portion of hemoglobin. CO 2 + Hb HbCO 2

23. Carbon Dioxide Transport Carbonic Acid Formation The carbonic anhydrase stimulates water to combine quickly with carbon dioxide. CO 2 + H 2 H 2 CO 3

24. Carbon Dioxide Transport Bicarbonate Ion Formation Carbonic acid breaks down to release a hydrogen ion and bicarbonate. H 2 CO 3 H + + HCO - 3

25. 30 30 CO 2 Transport and Cl - Movement

26. This shifts the oxygen- haemoglobin dissociation curve to the right. Thus formation of bicarbonate ion enhances oxygen uploading. Bicarbonate Ions This also plays a buffering as the H+ is neutralised therefore preventing any acidification of the blood. When blood enters the lungs, where the PCO2 is lower, the H+ and bicarbonate ions rejoin to form carbonic acid, which then splits into carbon dioxide and water. In other words the carbon dioxide is re-formed and can enter the alveoli and then be exhaled. Key Point The majority of carbon dioxide produced by the active muscles is transported back to the lungs in the form of bicarbonate ions. Carbaminohaemoglobin CO2 transport also can occur when the gas binds with haemoglobin , forming a compound called Carbaminohaemoglobin . It is named so because CO2binds with the amino acids in the globin part of the haemoglobin , rather than the haeme group oxygen does. EXTRA

27. The dissolved carbon dioxide comes out of solution where the PCO2 is low, such as in the lungs. There it diffuses out of the capillaries into the alveoli to be exhaled. Bicarbonate Ions Bicarbonate Ions Carbon Dioxide and water molecules combine to form carbonic acid (H2CO3). This acid is unstable and quickly dissociates, freeing a hydrogen ion (H+) and forming a bicarbonate ion (HCO3-): CO2 + H2O H2CO3 CO2 + H2O Bicarbonate Ions The H+ subsequently binds to haemoglobin and this binding triggers the BOHR effect (mentioned earlier). EXTRA

28. Carbon Dioxide Dissociation Curve Haldane effect For any given PCO 2 , the blood will hold more CO 2 when the PO 2 has been diminished. Reflects the tendency for an increase in PO 2 to diminish the affinity of hemoglobin for CO 2 .

29. Mechanism of Haldane effect Combination of oxygen with hemoglobin in the lungs cause the hemoglobin to becomes a stronger acid. Therefore: The more highly acidic hemoglobin has less tendency to combine with CO 2 to form CO 2 Hb The increased acidity of the hemoglobin also causes it to release an excess of hydrogen irons.

30. Interaction Between CO2 and O2 Transportation 1. Bohr effect

31. 2. Haldane effect