hemoglobin. hemoglobin ► blood can carry very little oxygen in solution. ► hemoglobin is...

HemoglobinHemoglobin


► Blood can carry Blood can carry very little oxygen in very little oxygen in solution.solution.

►Hemoglobin is Hemoglobin is required to carry required to carry oxygen around.oxygen around.

►Hemoglobin is found Hemoglobin is found in red blood cellsin red blood cells


► In fact if the body In fact if the body had to depend upon had to depend upon dissolved oxygen in dissolved oxygen in the plasma to supply the plasma to supply oxygen to the cells –oxygen to the cells –

► The heart would The heart would have to pump 140 have to pump 140 liters per minute - liters per minute - instead of 4 liters instead of 4 liters per minute.per minute.


► Each red blood cell Each red blood cell can carry about one can carry about one million molecules of million molecules of oxygen in its lifetimeoxygen in its lifetime

► Hemoglobin is 97% Hemoglobin is 97% saturated when it saturated when it leaves the lungsleaves the lungs

► Under resting Under resting conditions is it about conditions is it about 75% saturated when 75% saturated when it returns.it returns.


►Hemoglobin is made from two similar Hemoglobin is made from two similar proteins that "stick together". proteins that "stick together".

►Both proteins must be present for the Both proteins must be present for the hemoglobin to pick up and release hemoglobin to pick up and release oxygen normally. oxygen normally.

►One of the component proteins is One of the component proteins is called alpha, the other is beta. called alpha, the other is beta.


►Blood cells are made up of two Blood cells are made up of two components.components.

► The hemoglobin is in solution inside the The hemoglobin is in solution inside the cell. cell.

►The cell is surrounded by a membrane The cell is surrounded by a membrane that holds in the hemoglobin. that holds in the hemoglobin.

►A rough analogy would be a rubber water A rough analogy would be a rubber water balloon.balloon.

►The rubber would be the membrane, and The rubber would be the membrane, and the water would be the hemoglobinthe water would be the hemoglobin

Porphyrin RingPorphyrin Ring

► At the core of the At the core of the molecule is molecule is porphyrinporphyrin ring which holds an iron ring which holds an iron atom.atom.

► An iron containing An iron containing porphyrin is termed a porphyrin is termed a hemeheme. .

► This iron atom is the This iron atom is the site of oxygen binding. site of oxygen binding.

► The name hemoglobin is The name hemoglobin is the concatenation of the concatenation of heme and globin heme and globin


►Hemoglobin is a remarkable molecular Hemoglobin is a remarkable molecular machine that uses motion and small machine that uses motion and small structural changes to regulate its action.structural changes to regulate its action.

►Oxygen binding at the four heme sites in Oxygen binding at the four heme sites in hemoglobin does not happen hemoglobin does not happen simultaneously.simultaneously.

►Once the first heme binds oxygen, it Once the first heme binds oxygen, it introduces small changes in the structure introduces small changes in the structure of the corresponding protein chain. of the corresponding protein chain.


►These changes nudge the neighboring These changes nudge the neighboring chains into a different shape, making chains into a different shape, making them bind oxygen more easily.them bind oxygen more easily.

►Thus, it is difficult to add the first Thus, it is difficult to add the first oxygen molecule, but binding the oxygen molecule, but binding the second, third and fourth oxygen second, third and fourth oxygen molecules gets progressively easier molecules gets progressively easier and easier.and easier.

►This provides a great advantage in This provides a great advantage in hemoglobin function.hemoglobin function.


►When blood is in the lungs, where When blood is in the lungs, where oxygen is plentiful, oxygen easily oxygen is plentiful, oxygen easily binds to the first subunit and then binds to the first subunit and then quickly fills up the remaining ones. quickly fills up the remaining ones.

►Then, as blood circulates through the Then, as blood circulates through the body, the oxygen level drops while body, the oxygen level drops while that of carbon dioxide increases.that of carbon dioxide increases.


► In this environment, hemoglobin releases its In this environment, hemoglobin releases its bound oxygen. As soon as the first oxygen bound oxygen. As soon as the first oxygen molecule drops off, the protein starts molecule drops off, the protein starts changing its shape. changing its shape.

► This prompts the remaining three oxygens This prompts the remaining three oxygens to be quickly released. to be quickly released.

► In this way, hemoglobin picks up the largest In this way, hemoglobin picks up the largest possible load of oxygen in the lungs, and possible load of oxygen in the lungs, and delivers all of it where and when needed.delivers all of it where and when needed.

Iron and HemoglobinIron and Hemoglobin

► The mineral, iron, plays The mineral, iron, plays an important role in the an important role in the body’s delivery and use body’s delivery and use of oxygen to and by of oxygen to and by working muscles. working muscles.

► It binds oxygen to It binds oxygen to hemoglobin, which hemoglobin, which then travels in the then travels in the bloodstream to bloodstream to locations throughout locations throughout the body. the body.

Iron and HemoglobinIron and Hemoglobin► Generally, the more Generally, the more

oxygen there is being oxygen there is being delivered, the greater delivered, the greater the body’s ability to the body’s ability to perform work.perform work.

► For this reason, iron For this reason, iron receives much attention receives much attention for its role in supporting for its role in supporting aerobic exercise, and it aerobic exercise, and it has been postulated has been postulated that a lack of iron in the that a lack of iron in the body can reduce aerobic body can reduce aerobic capacity and impair capacity and impair endurance performance. endurance performance.

Iron and HemoglobinIron and Hemoglobin

► Iron deficient red Iron deficient red blood cellsblood cells

► Low number of cellsLow number of cells►Note the hollow and Note the hollow and

blanched blanched appearance of the appearance of the red blood cells.red blood cells.

Sickle Cell anemiaSickle Cell anemia

► Sickle Cell Anemia is a Sickle Cell Anemia is a genetic disorder that is genetic disorder that is characterized by the characterized by the formation of hard, sticky, formation of hard, sticky, sickle-shaped red blood sickle-shaped red blood cells, in contrast to the cells, in contrast to the biconcave-shaped red biconcave-shaped red blood cells (RBCs) found blood cells (RBCs) found in “normal” individuals. in “normal” individuals.

► This disease is caused This disease is caused by a mutation in by a mutation in hemoglobin. hemoglobin.

ThalassemiaThalassemia

► It consists of two It consists of two different proteins, an different proteins, an alphaalpha and a and a betabeta..

► If the body doesn't If the body doesn't produce enough of produce enough of either of these two either of these two proteins, the red blood proteins, the red blood cells do not form cells do not form properly and cannot properly and cannot carry sufficient oxygen. carry sufficient oxygen.

► The result is anemia The result is anemia that begins in early that begins in early childhood and lasts childhood and lasts throughout life.throughout life.

PorphyriaPorphyria

► Porphyria is a group Porphyria is a group of different of different disorders caused by disorders caused by abnormalities in the abnormalities in the chemical steps chemical steps leading to the leading to the production of hemeproduction of heme

PorphyriaPorphyria

► It is characterized by It is characterized by extreme sensitivity to light extreme sensitivity to light (exposure to sunlight (exposure to sunlight causes vesicular erythema), causes vesicular erythema), reddish-brown urine, reddish-brown urine, reddish-brown teeth, and reddish-brown teeth, and ulcers which destroy ulcers which destroy cartilage and bone, causing cartilage and bone, causing the deformation of the nose, the deformation of the nose, ears, and fingers. Mental ears, and fingers. Mental aberrations, such as aberrations, such as hysteria, manic-depressive hysteria, manic-depressive psychosis, and delirium, psychosis, and delirium, characterize this condition characterize this condition as well. as well.