Chromosomes 3. Meiosis 4. Inheritance 5. Genetic Modification 4: Ecology 1. Energy Flow 3. Carbon Cycling 4. Climate Change 5: Evolution 1. Evolution Evidence 2. Natural Selection 3. Classification 4. Cladistics 6: Human Physiology 1. Digestion 2. The Blood System 3. Disease Defences 4.
Gas Exchange 5. Homeostasis Higher Level 7: Nucleic Acids 1. DNA Structure 2. Transcription 3. Hemoglobin is the primary transporter of oxygen with an oxygen binding capacity between 1. About Hemoglobin is a protein found in red blood cells also called erythrocytes. There are roughly million hemoglobin molecules in a single red blood cell, and each contains 4 heme groups. The function of Hgb is to provide a binding site for oxygen to carry oxygen throughout the bloodstream to the systemic tissues for cellular respiration.
Hemoglobin : Hemoglobin is the iron-containing, oxygen-transport metalloprotein in the red blood cells of all vertebrates. About 1. It has an oxygen binding capacity between 1. The percentage of oxygen that is saturated in the hemoglobin of blood is generally represented by a curve that shows the relationship between PaO 2 and O 2 saturation.
Saturation of O 2 in hemoglobin is an indicator for how much O 2 is able to reach the tissues of the body. Higher PaO 2 means higher saturation of oxygen in blood. The carrying capacity can be increased if more hemoglobin is added to the system, such as through greater red blood cell generation in high altitude, or from blood transfusions.
The lower areas of the curve show saturation when oxygen is unloaded into the tissues. The oxyhaemoglobin dissociation curve : The oxygen—hemoglobin dissociation curve plots the percent hemoglobin saturation y-axis against the partial pressure of oxygen in the blood PO 2.
The blue curve is standard curve, while the red and green curves are right and leftward shifts respectively. The oxyhemoglobin dissociation curve can shift in response to a variety of factors. A change in the P 50 of the curve is a sign that the dissociation curve as a whole has shifted. Rightward shifts indicate a decreased affinity for the binding of hemoglobin, so that less oxygen binds to hemoglobin, and more oxygen is unloaded from it into the tissues.
The curve shifts right during decreased blood pH called the Bohr effect , increased temperature, and during exercise among other things.
Anemia a disorder marked by a decreased red blood cell count and less hemoglobin also causes a rightward shift, but also changes the shape of the curve so that it moves downward as well as a result of the reduced levels of hemoglobin.
Leftward shifts indicate an increased affinity for the binding of hemoglobin, so that more oxygen binds to hemoglobin, but less oxygen is unloaded from it into the tissues. Causes of leftward shifts include increased blood pH, decreased temperature, and carbon monoxide exposure. Carbon monoxide binds to hemoglobin in place of oxygen, so that less oxygen reaches the tissues; this can be fatal if severe enough.
CO 2 is carried in blood in three different ways: dissolved in plasma, bound to hemoglobin, or as a biocarbonate ion. Carbon dioxide is the product of cellular respiration, and is transported from the cells of tissues in the body to the alveoli of the lungs through the bloodstream. Carbon dioxide is carried in the blood through three different ways.
Carbon dioxide has a much higher solubility than oxygen, which explains why a relatively greater amount of carbon dioxide is dissolved in the plasma compared to oxygen. Structure of human hemoglobin : Hemoglobin is a tetramer of alpha red and beta blue subunits with iron containing heme groups green. While oxygen binds to the iron content in the heme of hemoglobin, carbon dioxide can bind to the amino acid chains on hemoglobin.
When carbon dioxide clings to hemoglobin it forms carbanimohemoglobin. Carbanimohemoglobin gives red blood cells a bluish color, which is one of the reasons why the veins that carry deoxygenated blood appear to be blue. A property of hemoglobin called the Haldane effect states that deoxygenated blood has an increased capacity to carry carbon dioxide, while oxygenated blood has a decreased capacity to carry carbon dioxide.
This property means that hemoglobin will primarily carry oxygen in systemic circulation until it unloads that oxygen and is able to carry a relatively higher amount of carbon dioxide. The reaction that describes the formation of bicarbonate ions in the blood is:. This means that carbon dioxide reacts with water to form carbonic acid, which dissociates in solution to form hydrogen ions and bicarbonate ions.
The main implication of this process is that the pH of blood becomes a way of determining the amount of carbon dioxide in blood. This is because if carbon dioxide increases in the body, it will manifest as increased concentrations of bicarbonate and increased concentrations of hydrogen ions that reduce blood pH and make the blood more acidic.
Conversely, if carbon dioxide levels are reduced, there will be less bicarbonate and less hydrogen ions dissolved in the blood, so pH will increase and blood will become more basic. Bicarbonate ions act as a buffer for the pH of blood so that blood pH will be neutral as long as bicarbonate and hydrogen ions are balanced.
This connection explains how ventilation rate and blood chemistry are related, as hyperventilation will cause alkalosis, and hypoventilation will cause acidosis, due to the changes in carbon dioxide levels that they cause.
Bicarbonate is also carried in the fluids of tissues besides the blood vessels, especially in the duodenum and intestine, so problems in those organs can cause a respiratory system response. After carbon dioxide travels through the bloodstream to the capillaries covering the alveoli of the lungs through any of the 3 methods listed above, it must return to dissolved carbon dioxide form in order to diffuse across the capillary into the alveolus.
Dissolved carbon dioxide is already able to diffuse into the alveolus, while hemoglobin-bound carbon dioxide is unloaded into the plasma. For carbon dioxide stored in bicarbonate, it undergoes a reaction reversal. The depth of breathing can be measured using a spirometer a device that measures the volume of air inhaled and exhaled.
To investigate the effects of exercise on breathing, record the rate of breathing for a few minutes when the person is at rest. After they do some exercise, record their rate of breathing every minute until it returns to the normal resting value.
The pH of the blood is normally 7.
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