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What's the mixture of carbon and haemoglobin called

What's the mixture of carbon and haemoglobin called


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I know of oxyhaemogloblin , the mixture of oxygen and haemoglobin , but carbon and haemoglobin combination is what's confusing


I'm going to agree with the comment left by @anongoodnurse and assume you are looking for the terms that define CO2 + hemoglobin and CO + hemoglobin.

CO2 + hemoglobin = Carbaminohemoglobin

CO + hemoglobin = Carboxyhemoglobin


Haemoglobin

Haemoglobin (also hemoglobin, or abbreviated Hb) is a protein which is used in red blood cells to store and transport oxygen. It is found in many multi-cellular organisms such as mammals where simple diffusion would be unable to supply adequate oxygen to tissue and cells.

Haemoglobin is made up of four polypeptide subunits, two alpha (α) subunits and two beta (β) subunits. Each of the four subunits contains a heme ( contains iron) molecule, where the oxygen itself is bound through a reversible reaction, meaning that a haemoglobin molecule can transport four oxygen molecules at a time.

The reversible nature of the binding of oxygen allows for both the uptake of oxygen in the lungs and its release in body tissues.

The heme molecules each contain a single central iron atom and are responsible for giving the red colour to haemoglobin, and thus to the blood as a whole.  [1]

The four subunits of Hemoglobin are similar to myoglobin [2] . Myoglobin is a single polypeptide, existing in either the deoxymyoglobin form (not bound to oxygen) or the oxymyoglobin form (bound to oxygen) [3] . Myoglobin contains heme [4] . Heme contains a central iron atom surrounded by protoporphyrin, which is the organic component [5] . When O2 binds to the iron atom (the iron must be in the Fe 2+ state for O2 to bind), the iron atom actually moves from outside of the plane of the porphyrin to within the plane of the porphyrin [6] .

The binding of O2 in hemoglobin is cooperative, meaning that the binding of O2  in each of the one subunit is not independent of the binding at other subunits [7] , so as one oxygen binds to a heme group it causes conformational changes to the other heme groups making them more accesible to oxygen, thus leading to the successive binding of other oxygen atoms [8] . Even though myoglobin has a higher affinity for O2 than hemoglobin, hemoglobin is more effective and efficient at delievering oxygen to tissues. In lungs,㻢% of hemoglobin is saturated, whereas in the tissues, only 32% of hemoglobin is saturated [9] . This means that in the tissues, 66% of hemoglobin subunits released their oxygen. In contrast, in lungs, 98% of myoglobin would be saturated, and 91% of myoglobin would be saturated in tissues [10] . Compared to myoglobin, hemoglobin has a much more complete. Hemoglobin has a T and R state. In the T (tense) state, or deoxygenated state, the binding sites of hemoglobin are constrained. In the R (relax) state, or oxygenated state, the binding sites are less constrained, making it easier for the hemoglobin subunits to bind to oxygen [11] . There are two models that attempt to explain the cooperativity of hemoglobin. The first model is the concerted, or MWC model. This model proposes that whenever an O2 molecule binds to a subunit of hemoglobin, it shifts the equilibrium between the T and R states. According to this model, when none of the hemoglobin subunits are bound to oxygen, the T state of the protein is favored. As more and more sites are bound to oxygen, the reaction shifts to favor the R state. A transition from the T state to the R state will increase the binding affinity of the other sites for O2. The sequential model, on the other hand, suggests that you don't have to have a conversion from the T state to the R state to increase the affinity of other binding sites. A mixture of both models explains what is observed about hemoglobin cooperativity better than either one of these models can achieve on its own. It is observed that when 3 out of 4 subunits of hemoglobin are bound to O2, the protein is almost always in the R state. Another observation is that when 1 out of 4 hemoglobin subunits are bound to O2, the protein is almost always in the T state [12] .

In its quarternary structure is a globular protein, its chains are closely coiled together to form a compact, almost spherical molecule. A single molecule consists of 4 subunits: two α-polypeptide chains (each identical and containing 141 amino acids) and two β-polypeptide chains (each identical and containing 146 amino acids). The location of the genes for both types of polypeptide chains differs: α-chain gene is located on chromosome 16, the β-chain gene is located on chromosome 11. [13]

Each polypeptide is associated with haem, which is the prosthetatic group that mediates reversible binding of oxygen by haemoglobin. It contains a ferrous (Fe 2+ ) ion. Each Fe 2+ ion can combine with a single oxygen molecule (O2), making a total of four oxygen molecules that can be carried to the tissues and return carbon dioxide (CO2) from the tissue to the lungs. [14]

The cell that produces haemoglobin is called an erythrocte (also known as RBC, red blood cell). Each red cell contains about 280 million molecules of haemoglobin. [15]

Haemoglobin (also spelled hemoglobin) is iron containing compund that binds to oxygen gas. It is found in the red blood cells of vertebrates. It transports oxygen from the respiratory organ, the lungs, to the different cells of body. It is a protein that contains a quaternary structure made up of 4 sub-units. They consist of 2 alpha sub units and 2 beta subunits. Each subunit conatins a heme group which contains and iron atom. Each iron atom binds to 1 oxygen molecule. Thus 1 haemogobin molecule transports 8 atoms of oxygen. When absorbtion of oxygen occurs haemoglobin becomes oxyhaemoglobin and it forms the reddish colour of the red blood cells. Upon arrival at a cell it deposits its oxygen thus allowing oxidization of glucose to take place via respiration. This releases energy in form of ATP. The waste product, carbon dioxide is transported by haemoglobin to the lungs for expiration [16] .

Haemoglobin also acts as a buffer that helps maintain the physiological pH. It has a histidine group that can uptake H+ ions when the pH decreases and dissociate to release H+ ions when pH increases [17] . When it works together with the lungs, it is able to control the uptake of carbon dioxide which controls the bicarbonate buffer system thus being able to sustain the physiological pH. 


Hydrocarbon Chains

Hydrocarbon chains are formed by successive bonds between carbon atoms and may be branched or unbranched. Furthermore, the overall geometry of the molecule is altered by the different geometries of single, double, and triple covalent bonds, illustrated inFigure. The hydrocarbons ethane, ethene, and ethyne serve as examples of how different carbon-to-carbon bonds affect the geometry of the molecule. The names of all three molecules start with the prefix “eth-,” which is the prefix for two carbon hydrocarbons. The suffixes “-ane,” “-ene,” and “-yne” refer to the presence of single, double, or triple carbon-carbon bonds, respectively. Thus, propane, propene, and propyne follow the same pattern with three carbon molecules, butane, butane, and butyne for four carbon molecules, and so on. Double and triple bonds change the geometry of the molecule: single bonds allow rotation along the axis of the bond, whereas double bonds lead to a planar configuration and triple bonds to a linear one. These geometries have a significant impact on the shape a particular molecule can assume.

When carbon forms single bonds with other atoms, the shape is tetrahedral. When two carbon atoms form a double bond, the shape is planar, or flat. Single bonds, like those found in ethane, are able to rotate. Double bonds, like those found in ethene cannot rotate, so the atoms on either side are locked in place.


  1. Essay on the Definition of Haemoglobin
  2. Essay on the Properties of Haemoglobin
  3. Essay on the Functions of Haemoglobin
  4. Essay on the Varieties of Haemoglobin
  5. Essay on the Existence of Haemoglobin
  6. Essay on the Inclusion of Haemoglobin
  7. Essay on the Synthesis of Haemoglobin
  8. Essay on the Estimation of Haemoglobin
  9. Essay on the Variation of Haemoglobin
  10. Essay on the Derivatives of Haemoglobin

Essay # 1. Definition of Haemoglobin:

Haemoglobin is the red pigment of blood. It is a chromo protein consisting of two parts: One part (96%) is a specific simple protein known as globin (histone) and the other (4 %) is a non-specific prosthetic group-an iron-contain­ing pigment called haem (Flow chart 4.1).

Haem is a protoporphyrin compound and consists essentially of four pyrrole groups joined together. The porphyrin molecule can combine with metals forming metalloporphyrin compounds. Haem is a metalloporphyrin where the metal is iron. The iron content of haemoglobin is about 0.34% and about 3 gm iron is present as haemoglobin in the total amount of blood of an adult. Iron remains in ferrous (Fe ++ ) form. Globin helps haem to keep the iron in ferrous state and to combine loosely and reversibly with molecular oxygen.

The molecular weight of haemoglobin is about 68,000. It contains 4 atoms of iron and 8 atoms of sulphur. The haemoglobin molecule is probably an aggregate of four unitary molecules, each having one atom of iron and two atoms of sulphur and with a molecular weight of 17,000. The approximate chemical formula is (C712H1130O245N214S2Fe)4.

Essay # 2. Properties of Haemoglobin:

i. The most characteristic property of haemoglobin is the ease with which it combines with oxygen and dissociates from it. 100 ml of water will absorb one-third ml of oxygen at body temperature under atmospheric pressure. But 100 ml of blood, under the same condition, will take up 20 ml of oxygen (60 times), due to the presence of haemoglobin. [About 1,200 ml of oxygen can be carried by the total amount of blood in an adult man.]

One gram of haemoglobin combines at normal (standard) temperature pressure (NTP) with 1.34 ml of oxygen. This corresponds to two atoms of oxygen for each atom of iron. The compound oxyhaemoglobin gives off its full oxygen content when placed in vacuum.

ii. Oxyhaemoglobin holds its oxygen loosely which can be easily displaced by many other gases forming more stable compounds, e.g., CO, NO, H2S will form carboxyhaemoglobin (carbonmonoxy-haemoglobin), nitric oxide haemoglobin, sulphaemoglobin respectively.

iii. The globin part of haemoglobin directly combines with CO2 and forms carbamino compounds.

iv. Crystallisation- Haemoglobin can be easily crystallised. The form of the crystals, their solubility and the ease of crystallisation are characteristic of the species from which haemoglobin is obtained. Most bloods, including human blood, form rhombic prisms or needles. Haemoglobins of different species are said to be immunologically distinct.

The distinction lies in the globin part of the molecule and not in the haem part. It is known that the amino acid composition of the various globins (derived from haemoglobin of different species) varies considerably specially in respect to their cystine content. The haemoglobin of different species also shows different affinity for oxygen.

v. Isoelectric pH of haemoglobin (reduced Hb) is 6.8 that of oxyhaemoglobin is 6.6.

vi. Spectroscopic Appearance Haemoglohin (reduced Hb) gives one broad band between the Fraunhofer’s lines D and E (corresponding to the wave-length-λ 559). That of oxyhaemoglobin consists of two bands between D and E. The band nearer D is called α-band (corresponding to the wave-length -λ 579). The band nearer E is broader and is called the β-band (with a corresponding wave length of λ 542).

Essay # 3. Functions of Haemoglobin:

1. It is essential for oxygen carriage.

2. It plays an important part in CO2 transport.

3. It constitutes one of the important buffers of blood and helps to maintain its acid-base balance.

4. Various pigments of bile, stool, urine, etc., are formed from it.

Essay # 4. Varieties of Haemoglobin:

In man probably there are at least two varieties of haemoglobin, the foetal haemoglobin (HbF) and the adult haemoglobin (HbA). Foetal haemoglobin differs chemically and spectroscopically from the adult haemoglobin. It has a greater affinity for oxygen and releases CO2 more readily. This is due to some difference in the globin fraction. This property helps to compensate the relative anoxia of foetal blood.

At low O2 pressure foetal haemoglobin can take up larger volumes of O2 than adult haemoglobin. Foetal haemoglobin is 70 percent saturated at 20 mm of O2, pressure whereas adult haemoglobin is only 20 per cent saturated at this pressure. A small quantity of foetal haemoglobin persists for some weeks or months after birth.

Essay # 5. Existence of Haemoglobin:

The actual state in which haemoglobin exists in the red cells is not yet fully understood. The quantity of haemoglobin in the red cells is too great for it to be in simple solution and it is also known that it is not present in crystalline form.

From these observations it has been suggested that haemoglobin remains in some combined form. It is believed that haemoglobin remains absorbed to the lipid material of the stroma and the envelope of red cells. In certain lower invertebrates, haemoglobin remains free in the plasma. Its inclusion in the red cells has taken place gradually in the course of evolution.

Essay # 6. Inclusion of the Haemoglobin:

Causes of Inclusion of the Haemoglobin in Red Cells:

1. Though haemoglobin is protein having its molecular weight 68,000 yet it passes through the endothelial lining of the blood vascular system as well as through the normal glomerular membrane. Haemoglobinuria is the condition when free haemoglobin is excreted through the urine. If Hb is free in the plasma then it is excreted through the urine.

In plasma, Hb is present normally bound to protein at a concentration of about 5 mg/100 ml of whole blood. In plasma Hb remains normally as haemoglobin-heptoglobin complex which cannot pass through the urine. Under normal condition about 100 to 150 mg of free Hb is released from red cells due to haemolysis. Hb can be bound as haemoglobin-hepatoglobin complex by the hepatoglobin present in the plasma.

If released Hb exceeds the capacity of the hepatoglobin to bind the haemoglobin, then it is excreted through the urine. The free Hb passes readily through the glomerulus and of which cer­tain amount is reabsorbed and rest is excreted through the urine. During reabsorption of Hb through the tubular epithelium certain amount of it, is converted into haemosiderin and excreted in the urine.

So plasma Hb concentration is always associated with haemosiderinuria though the condition of haemoglobinuria may or may not be happened. Thus, if the Hb was not enclosed by the cell membrane of erythrocytes then this Hb would have been passed quickly through glomerular membrane and excreted through the urine. Because R.B.C. cannot pass through the glomerular membrane in normal condition.

Haemoglobinuria may be caused under the following conditions:

ii. Due to mismatched blood transfusion.

iii. Black water fever due to virulent type of malaria and red-water fever due to another type of parasite which invades the erythrocyte causing release of Hb in the plasma.

iv. Paroxysmal nocturnal haemoglobinuria.

vi. Thermal or chemical injuries.

vii. Paroxysmal cold haemoglobinuria.

2. In transport of CO2 from the tissues to the lungs the erythrocyte with its haemoglobin plays an important part. Because the enzyme carbonic anhydrase is present within the erythrocyte.

3. If haemoglobin instead of staying within the corpuscles, remains free in the plasma (as occurs in haemolysis), many injurious effects will be produced. The degree of the deleterious effects will depend upon the number of red cells haemolysed and the rapidity of haemolysis.

Briefly the following ill effects will be produced:

i. Viscosity of blood will rise.

ii. The colloidal osmotic pressure, normally about 30, will rise to 100 mm of Hg or more. This will seriously disturb interchange of various substances in the capillary area and will also disturb the formation of urine.

iii. Loss of haemoglobin will reduce the amount of blood buffers and will cause acidosis. This is all the more enhanced by the disintegration of red cells, the loss of available surface area of the erythrocytes, which plays a considerable role in maintaining the acid-base balance and the ion balance in blood.

iv. Loss of haemoglobin will reduce the oxygen-carrying capacity of blood, thus producing anoxia and acidosis.

v. Bile pigments will be produced in larger amounts by the R. E. cells from the released haemoglobin and in this way additional pressure will be put upon the liver to deal with them.

vi. While being excreted through kidneys, haemoglobin will be precipitated in the acid urine and in this way the kidney tubules will be blocked. This will cause serious disturbance of the kidney function.

vii. As a delayed result, hypochromic anaemia will be produced.

Essay # 7. Synthesis of Haemoglobin:

Haemoglobin is synthesised inside the red cells in the bone marrow. A number of factors are necessary for the synthesis of haemoglobin.

1. First Class Proteins (Or Proteins of High Biological Value):

It is necessary for the synthesis of the globin part of haemoglobin. Certain individual amino acids, such as histidine, phenyl alanine, leucine, etc., have been found to possess a special stimulating action on haemoglobin formation. A diet containing kidney, spleen, heart and certain fruits are very helpful. Four kinds of globin peptide chains – α, β, γ and δ have been isolated. Human haemoglobin contains 2α and 2β chains. The haem portions are attached to the α and β chains.

It is an essential constituent of haemoglobin. Daily intake of 12 mgm is adequate

Copper, Manganese and Cobalt -These metals, particularly copper, help in the incorporation of iron in the protoporphyrin molecules for the formation of metalloporphyrin. The ratio between Cu: Fe in the daily diet should be 1: 100. Cobalt has a definite value as a constituent of vitamin B12. They act as catalytic agents.

Of the endocrines, only thyroxine is of proved value.

Vitamins C and B12 are definitely helpful in this respect. It is also believed that folic acid, riboflavin, nicotinic acid, pantothenic acid and pyridoxine also play some parts in the formation of haemoglobin.

Of the two types of porphyrins, I and III that are found in nature, the latter is utilised for haemoglobin formation. Studies with radioactive carbon show that protoporphyrin III, required for this purpose, is synthesised in the animal body from simpler substances like glycine, acetic acid, aceto-acetic acid, succinic acid or any amino acid that can give rise to the formation of succinic acid during metabolism or through tricarboxylic acid cycle.

Glycine and succinate help in the synthesis of protoporphyrin. Amino­levulinic acid (ALA) is formed by the interaction of succinate and glycine. Two molecules of aminolevulinic acid after condensation forms porphobilinogen (PBG). From porphobilinogen ultimately uroporphyrino­gen III formed.

On decarboxylation, the uroporphyrinogen III is converted into coproporphyrinogen III and which on oxidation ultimately gives rise to protoporphyrin III. Protoporphyrin III in presence of globin and Fe ++ is converted into haemoglobin. The steps involved in the synthesis of Hb (Hgb) can be presented schematically in Fig. 4.9.

Essay # 8. Methods of Estimation of Haemoglobin:

A drop of blood from the patient’s finger is soaked in a piece of filter paper and com­pared against a standard colour scale, before the blood on the filter paper dries up. This method does not give accurate results.

2. Haldane’s Haemoglobinometer:

(Haldane’s modification of Gower’s method). The instrument consists of two tubes, one of which contains 20 cu. mm of blood haemolysed with distilled water and saturated with CO gas. The colour of this tube is used as standard. In the other tube a little distilled water is taken and 20 cu mm of patient’s blood, collected from the finger-tip by a special pipette, is added.

When blood be­comes fully haemolysed, it is saturated with CO by passing coal gas through it. The colour developed is compared against that of the standard. If the colour of the unknown is stronger, it is diluted with distilled water until the tinge is same in both. The graduation up to which the blood has been diluted gives the percentage haemoglobin.

3. Gower’s Haemoglobinometer:

Here, the standard used is a solution of picrocarmine gelatin. Otherwise the method is same as Haldane’s. The disadvantage of this method is that the colour of the standard gradually fades away.

Here, instead of distilled water, (N/10) HCl is used. This converts haemoglobin into acid haematin. The colour developed is matched against that of standard and the result is obtained as in Hal­dane’s method.

5. Von Fleischl’s Haemometer:

Here, the standard used consists of a set of coloured glasses.

6. Colorimetric Method:

Here, the comparison is done with the help of a colorimeter.

7. Method of Van Slyke and Stadie:

For very accurate work the method of Van Slyke and Stadie should be used. In this method iron of haemo­globin is estimated and from that the corresponding amount of haemoglobin is calculated. The photoelec­tric methods of Haliday, Kerridge and Smith (1935) may be adopted.

8. Spectrophotometry Method:

It is the modern method and is based as the measurement of absorption of light at certain wave-lengths of cyamethaemoglobin formed by treating the haemoglobin with ferricyanide and then with KCN.

Essay # 9. Variations of Haemoglobin:

In the foetus the concentration is highest. At birth the average concentration is about 23 gm per 100 ml. By the end of third month it falls below normal, probably, because of deficiency of iron in milk. After this gradual recovery takes place and at the end of the first year, the average amount is 12.5 gm. Then it rises gradually up to normal figures.

In females, the amount of haemoglobin is slightly lower than in males. In adult females the average is 13.7%, in adult males 15.8%.

Variation of at least 10% occurs throughout the day. In the morning it is lowest in the evening highest.

At higher altitude haemoglobin percentage rises.

5. Exercise, Excitement, Adrenaline Injection:

Exercise, excitement, adrenaline injection etc. increase the amount of haemoglobin.

It should be noted from the above that normal variation of haemoglobin is mostly due to alteration of number of red cells and not due to any change in the absolute quantity of haemoglobin in each cell. Anything that alters the red cell count will alter the percentage of Hb proportionally.

Essay # 10. Derivatives of Haemoglobin:

It is a compound of haemoglobin with oxygen. Iron remains in the ferrous (Fe ++ ) state in haemoglobin. It is not a stable compound. Oxygen may be removed when the blood is exposed to a vacuum. It has got two absorption bands between D and E.

It is also a compound of haemoglobin with oxygen. It can be produced after treating the blood with potassium ferri cyanide. It is chocolate-brown in colour. It is a stable compound. Oxygen cannot be removed by exposing the blood to a vacuum. Iron remains in the ferric (Fe +++ ) state. It has got one absorption bands between C and D.

It is a compound of haemoglobin with CO2. The compound is formed by union of CO2 with the globin portion.

iv. Carboxyhaemoglobin or Carbonmonoxy-Haemoglobin:

Haemoglobin combined with CO instead of ox­ygen. It is present in blood in coal gas poisoning. It has got two absorption bands between D and E. The affinity of human haemoglobin at 38° C. for CO is 210 times greater than O2. The extremely poisonous nature of the gas can easily be understood from the above statement.

It is formed by the combination of haemoglobin with H2S. The compound is very stable and is sometimes found in the blood after certain kinds of drag poisoning.

vi. Nitric Oxide Haemoglobin:

Haemoglobin combined with NO instead of oxygen, found in nitric oxide poisoning.

This derivative can exist in two forms – acid and alkaline and may be prepared from haemoglobin by the action of acid or alkali. This is sometimes found in the urine in old cases of haemorrhage. It is a ferric compound. Acid haematin has got an absorption band between C and D. The absorption band of alkaline haematin is near D line.

Haemin is haematin hydrochloride. It is prepared by boiling oxyhaemoglobin with NaCl and glacial acetic acid. It is a ferric compound.

When alkaline haematin is reduced by ammonium sulphide, this derivative is ob­tained. It is a ferrous compound. Haem with ferrous iron is combined with denatured globin. Of all the haemoglobin derivatives, haemochromogen possesses the most characteristic spectrum. It has a very distinct band between D and E, as well as a fainter band between E and b lines. Due to this property this compound is often used to identify doubtful blood stains.

It is a compound of haem containing ferric iron with denatured globin.

It is a ferrous compound produced by the reduction of haematin in alkaline solution.

This derivative can exist in two forms-acid and alkaline. It is prepared by mixing blood with sulphonic acid. When mixed with alkali the alkaline variety is formed. Normal urine may contain traces. It is found in the blood and urine in sulphonal poisoning and in certain cases of liver disease.

When haematoporphyrin is reduced, this compound is formed. It is probably a mix­ture of several pyrrole compounds.

This compound is produced by the breakdown of haemoglobin in the body. It is found as yellowish-red crystals in the region of old blood extravasations. Some authors believe that it is identical with bilirubin.

It is the chief pigment of bile and is produced from haemoglobin in the whole of the re- ticulo-endothelial system. From it are derived all the other bile pigments, the pigment of the stool, stercobilin the pigments of the urine, such as urobilinogen, urobilin and urochrome.


Triglycerides

All triglycerides are made from a glycerol 'head' and 3 fatty acid 'tails'. Glycerol is a type of alcohol. The fatty acids are organic molecules and all have a -COOH group attached to a hydrocarbon tail. Fatty acids are attached to glycerol by a condensation reaction.

One of their important properties is that they are insoluble in water - but soluble in certain organic solvents, including ether, ethanol and chloroform. This is because of the hydrocarbon tails of the fatty acids - which basically means that the tail is only carbon combined with hydrogen, creating no uneven distribution of electrical charge (unlike water molecules, which are polar). This means that they cannot mix freely with water molecules, and so are hydrophobic and non-polar.

Their roles are usually as fantastic energy reserves - as you'll see in the coming paragraphs they are incredibly rich in carbon-hydrogen bonds ready to be oxidised for energy. The same mass of lipid will have more energy than the same mass of carbohydrate. Fat also provides buoyancy in the form of blubber for sea mammals - whilst providing insulation, as it does for all mammals. They can also, in unusual circumstances be used as a metabolic source of water - oxidising them for energy converts them to carbon dioxide and then water. This is useful for animals living in the desert that do not have much or any water.


Nitrosamines derived from nicotine and other tobacco alkaloids

Hemoglobin binding

Hemoglobin adducts of carcinogens are potentially useful as biomarkers of metabolic activation. Advantages of hemoglobin adducts over DNA adducts include the relative ease with which hemoglobin can be obtained in quantity, the lack of repair of adducts, and the relatively long lifetime of red blood cells in humans (120 days), potentially allowing adduct accumulation [ 281 , 282 ]. With these potential advantages in mind, determination of hemoglobin binding of NNK and NNN could provide a way for identifying tobacco- or tobacco smoke-exposed individuals who are particularly adept at activating NNK and NNN, and thus could be at a higher risk for cancer.

Initial biomonitoring studies reported elevated HPB-releasing hemoglobin adduct levels in American snuff dippers (517±538 fmol HPB/g globin) and smokers (80±189 fmol HPB/g globin) compared to non-smokers (29±26 fmol HPB/g globin) [ 283 ]. A large heterogeneity in adduct levels was confirmed in an extended study of smokers (mean 163 fmol HPB/g globin) and non-smokers (mean 68 fmol HPB/g globin) [ 284 ]. More recent studies from Germany report lower hemoglobin adduct levels in smokers (69 ±44 fmol HPB/g globin) and non-smokers (34±16 fmol HPB/g globin) [ 285 ], and in pregnant smoking (55±46 fmol HPB/g globin) and non-smoking (27±35 fmol HPB/g globin) women (286). Data obtained by the International Agency for Research on Cancer report even lower hemoglobin adduct levels in smokers (26± 12 fmol HPB/g globin) and non-smokers (19±8 fmol HPB/g globin) [ 287 ]. No association is found between self-reported ETS exposure and HPB-releasing hemoglobin adduct levels in non-smokers [ 286 ]. Thus, HPB-releasing hemoglobin adducts have limited utility as biomarkers of exposure to TSNA in smokers because adduct levels are frequently not much higher than assay background amounts [ 35 ], and are unsuitable as biomarkers of ETS exposure in non-smokers [ 286 ].

TSNA-derived HPB-releasing hemoglobin adducts in smokers are considerably lower than adducts formed from other tobacco smoke and environmental carcinogens such as BaP [ 288 ] and 4-aminobiphenyl [ 285 ]. The comparatively low levels of HPB-releasing hemoglobin adducts is probably a consequence of the relative instability of α-hydroxymethylNNK compared to the reactive metabolites formed from BaP and 4-aminobiphenyl. The higher levels of HPB-releasing adducts in snuff-dippers [ 266 , 283 ] compared to smokers [ 266 , 283 , 285–287 ] may be due to differences in pharmacokinetics between orally absorbed NNK/NNN compared to inhaled substance. Alternatively, other constituents of tobacco smoke, not present in snuff, may inhibit α-methyl hydroxylation of NNK and/or 2′-hydroxylation of NNN.


Demo: BTB and Carbon Dioxide

I have used this demonstration every year to introduce the scientific method. The worksheet below is optional and includes instructions for writing a lab report and doing a more involved investigation, but for the beginning of the year, I prefer to just have students observe and give their suggestions for how to test various hypotheses.

The set-up is simple. Place bromothymol blue in a flask and use a straw to blow into the liquid. For drama, make sure you put on safety goggles. The BTB will turn yellow after you’ve blown into it, this change occurs because the carbon dioxide in your breath is acidic and BTB is an indicator.

Note on BTB: Color may vary when you first open the container. It may appear more yellow/green then blue. Create a “stock” to use with the class by adding a weak base (NaOH) to get the color to a blue. I mix this in a 500 ml flask and then pour the mixture into smaller beakers or flasks so that each demonstration starts at the same color.

Beginning questions should start with how do they know it changed color? If you don’t blow into the mixture for very long, the color change will be subtle. This is where you can guide students to the concept of a control. Create another experiment where you have two flasks that start out at the same color, blow into one and then students can be sure a color change has occurred.

The next part of the discussion asks students to propose ideas for WHY the solution changed color. Was it something in the breath? Was it the bubbling/mixing of the liquid? Did I put something into the mixture through the straw? Ask students to propose ways for each of these hypotheses to be tested. I will often have an aquarium pump sitting nearby for inspiration. Eventually a student will suggest to use the pump to blow bubbles instead of my breath. When you test this, there will be no color change.

In the last part, discuss what is it about the breath that makes the color change. This part might require more guidance depending on how much chemistry students have been exposed to. Use acidic and basic solutions to show students how BTB changes colors and why it is known as an indicator. You can also show them other indicators, like phenol red and show them how pH paper works.

For a more structured activity, download this handout and provide students with their own materials. Do go over safety precautions, students should wear safety goggles and take care to not ingest BTB.

NGSS – Science Practices: 1. Asking questions (for science) 2. Developing and using models 3. Planning and carrying out investigations 4. Analyzing and interpreting data 5. Using mathematics and computational thinking 6. Constructing explanations (for science) and designing solutions (for engineering) 7. Engaging in argument from evidence 8. Obtaining, evaluating, and communicating information


What's the mixture of carbon and haemoglobin called - Biology

  1. ? To maintain body temperature
  2. ? To produce bile
  3. ? To transport food to the stomach
  4. ? To support the body
  1. ? They are smaller than red blood cells.
  2. ? They are produced in bone marrow.
  3. ? They have no definite shape.
  4. ? They are capable of fighting infection.
  1. ? The oxygen in the blood makes it a brighter red.
  2. ? The carbon dioxide in the blood makes it a brighter red.
  3. ? Hormones in the blood make it a bright red.
  4. ? The lungs add a dye to the blood as it flows through.
  1. ? Blood cells are transported in the plasma.
  2. ? There are only two types of blood cell.
  3. ? White blood cells contain haemoglobin.
  4. ? All blood cells are produced in the kidneys.
  1. ? carry oxygen to the body's cells.
  2. ? clot blood.
  3. ? fight disease.
  4. ? carry carbon dioxide to the body's cells.
  1. ? carry oxygen around the body.
  2. ? remove carbon dioxide from cells in the body.
  3. ? clot wounds
  4. ? fight disease
  1. ? A = red cell, B = white cell, C= platelet
  2. ? A = red cell, B = platelet, C= white cell
  3. ? A = white cell, B = platelet, C= red cell
  4. ? A = white cell, B = red cell, C= platelet
  1. ? It has thin walls with valves, and carries blood to the heart.
  2. ? It has thick walls with valves and carries blood under pressure.
  3. ? It has a very thin wall with valves and carries blood under pressure.
  4. ? It has thin walls and carries oxygenated blood away from the heart.
  1. ? A = left atrium, B = septum
  2. ? A = septum, B = right ventricle
  3. ? A = left atrium, B = valve
  4. ? A = right atrium, B = aorta
  1. ? X = left ventricle and Y = pulmonary artery
  2. ? X = left atrium and Y = pulmonary artery
  3. ? X = right ventricle and Y = pulmonary vein
  4. ? X = left ventricle and Y = valve
In the capillary blood vessels, an exchange of gases takes place with cells. Which one of the following is the correct gas exchange?
  1. ? Oxygen leaves the capillary to the cell, and carbon dioxide enters the capillary.
  2. ? Carbon dioxide leaves the capillary to the alveolus, and oxygen enters the capillary.
  3. ? Nitrogen leaves the capillary to the cell, and carbon dioxide enters the capillary.
  4. ? Oxygen leaves the capillary to the cell, and nitrogen enters the capillary.
  1. ? Watching TV for 8 hours each day
  2. ? Exercising regularly
  3. ? Not smoking
  4. ? Eating a healthy diet
  1. ? changes in blood pressure in an artery
  2. ? the valves in an artery opening and closing
  3. ? red blood cells colliding with each other in the arteries
  4. ? oxygen entering the blood in the lungs
  1. ? Platelets form this clot.
  2. ? Haemoglobin leaves red blood cells to form the clot.
  3. ? Antibodies from white blood cells.
  4. ? Your body is running out of blood.
Which chamber of the heart does deoxygenated blood enter when returning from the body?
  1. ? The walls of capillaries are thick.
  2. ? Veins carry blood into the heart.
  3. ? The walls of veins are thin.
  4. ? There are no valves in arteries.
  1. ? Both oxygenated and deoxygenated blood
  2. ? Deoxygenated blood only
  3. ? Oxygenated blood only

CARBOHYDRATES

Carbohydrates are classified into two types on the basis of molecular weight.

Micromolecules – Monosaccharides and Oligosaccharides (Including Disaccharides)

Macromolecules – Polysaccharides

The micromolecules have the molecular weight of < 1000 Daltons whereas the
macromolecules have > 1000 Daltons as molecular weight.

    Why do we need carbohydrates in our food? Carbohydrates provides about 50-70% of total energy. We need average carbohydrate requirement in an adult is

There are three types of carbohydrates:

Monosaccharides

They are simplest carbohydrates, with 3 to 7 carbon atoms. All are reducing sugars with a free aldehyde (– CHQ) or ketone (– CO) groups.

  1. 3-carbons – TRIOSES (C3H6O3) – e.g. Glyceraldehyde (aldose) and Dehydroxyacetone (ketose) (Acetic acid (CH3COOH/ C2H4O2)and Lactic acid are not considered as carbohydrates)
  2. 4-carbons – TETROSES (C4H8O4) – e.g. Erythrose – an aldose (forms raw-material forlignin)
  3. 5-carbons – PENTOSES (C5H10O5) – e.g. Ribose (present in RNA, ATP and vitamin B2), Xylose and Arabinose – all aldoses, Ribulose – a ketose.
  4. 6-carbons – HEXOSES (C6H12O6) – e.g. Glucose, Galactose, Mannose (All aldose sugars) and Fructose (Ketose-sugar). Alcohol of mannose, called Mannitol, is found in brown algae.
  5. 7-carbons – HEPTOSES (C7H14O7) – e.g. Glucoheptose (Both Pentoses and Hexoses may occur in Ring form and Open chain)

Glucose – It is called Blood sugar or Grape sugar and occurs in 2-forms, i.e. D-form (Dextro-) and L-form (Levo-). All naturally occurring sugars are in D-form. It is an aldose sugar.

Fructose – It is called Fruit sugar. It is the most common sugar in plants. It is sweetest amongst naturally occurring sugars. It is a ketose sugar

Oligosaccharides

They contain 2 to 10 monosaccharide molecules.

A. Disaccharides – They contain 2-monosaccharides

(i) Maltose – It is malt sugar and is formed during germination of starchy seeds. It is a reducing sugar. It contains 2 α – glucose units with α – 1,4 linkage/glycosidic bond

(ii) Lactose – It is milk sugar. It is also reducing sugar. It contains 1α-glucose and 1β-galactose (with β–1,4-linkage/glycosidic bond). Lactose is maximum in human milk. The galactose, produced from milk digestion, is also the constituent of AgarAgar.

(iii) Sucrose – It is the sugar of sugar cane and sugar beet. It is non-reducing sugar as it does not have free aldehyde or ketose groups. It contains 1 α-glucose and 1 β-fructose units. (α – 1- 2 linkage/glycosidic bond) The equimolecular mixture of glucose and fructose is called Invert Sugar which is sweeter than sucrose.

(iv) Trehalose – It is a disaccharide (α 1-1 linkage) present in micro-organisms. It is also a non-reducing sugar.

(v) Cellobiose – It contains 2 β-glucose units (β 1-4 linkage). It cannot be digested by mammalian enzymes.

B. Trisaccharides – They contain 3 monosaccharides, ex. Raffi nose – 1 glucose + 1
fructose + 1 galactose

C. Dextrin – It is also an oligosaccharide and is formed during starch-digestion.

Polysaccharides

  • They are formed by joining of Monosaccharides (Monomers) by Glycosidic bonds between 1-4 carbon atoms. (In a polysaccharide chain the right end is called reducing end and the left end is called non-reducing end.
  • They are non-reducing and mostly insoluble in water.

Two types – 1. Storage polysaccharides – e.g. Glycogen and Starch

2. Structural polysaccharides – e.g. Cellulose and Chitin

  1. Glycogen – It is present in animals (also called animal starch). It is a branched chain compound and has about 30 α-glucose units. It gives ‘red colour’ with an iodine solution.
  2. Starch – It is present in plants. The natural starch contains a mixture of amylose (10-20%) and amylopectin (80-90%), latter branched and insoluble in water. It also contains all α-glucose. (Amylose in starch is responsible for ‘deep blue colour’ with iodine)
  3. Cellulose
    • It contains all β-glucose.
    • It is the most abundant organic compound in the biosphere.
    • It is a fibrous polysaccharide and forms cell wall in plants.
    • It forms roughage in human food.
    • It is a straight chain (unbranched) compound.
    • It forms 25 to 50% of wood and about 90% of cotton.
    • Each molecule of cellulose contains about 6000 units of monosaccharides (glucose) and hence is Homoglycan hexosan.
    • Rayon, an artifi cial and regenerated fi bre, is produced from cellulose.

    4. Chitin – It forms exoskeleton, mainly in arthropods. It is also present in the cell wall of fungi. Its unit is β-N- Acetylglucosamine. It is a homopolymer. The polysaccharide Agar has more than one type of Monosaccharide units (hence Heteroglycan). The polysaccharide Inulin (Dahlia starch) is a polymer of fructose (Homoglycan) with β-1,2 linkage.

    Conjugated or Complex Carbohydrates

    They contain carbohydrate with non-carbohydrate units

    1. Glycoproteins – e.g., Blood antigens, Collagen, Lens protein, Blood protein, Hormones like FSH, LH, TSH, hCG, and in cell membranes.
    2. Glycolipids – e.g., Blood antigens, nerve fibres and cell membranes
    3. Mucopolysaccharides – e.g., Heparin. Hyaluronic acid, Synovial fluid, Vitrous humour, Cell wall in bacteria and Mucilages ( Galactose and mannose). They are also present in Bhindi (Lady’s finger) and Isabgol

    Glucose Test – Benedict’s test, Fehling’s test.

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    HUMAN NERVOUS SYSTEM


    Examples of Heterotroph

    Herbivores

    Heterotrophs that eat plants to obtain their nutrition are called herbivores, or primary consumers.

    During photosynthesis, complex organic molecules (carbon dioxide) are converted into energy (ATP) through cellular respiration. The ATP is often in the form of simple carbohydrates (monosaccharaides), such as glucose, and more complex carbohydrates ( polysaccharides), such as starch and cellulose.

    Cellulose, which is a major component of plant cell walls and an abundant carbohydrate, converted from inorganic carbon, is harder to digest for many animals. Most herbivores have a symbiotic gut organism, which breaks down the cellulose into a usable form of energy.

    Examples of herbivores include cows, sheep, deer and other ruminant animals, which ferment plant material in special chambers containing the symbiotic organisms, within their stomachs. Animals that eat only fruit, such as birds, bats and monkeys, are also herbivores, although they are called frugivores. Most plant material consists mostly of hard-to-digest cellulose, although plant nectar consists of mostly simple sugars, and is eaten by herbivores called nectarivores, such as hummingbirds, bees, butterflies and moths

    Carnivores

    The energy that is transferred through the food chain, initially from the inorganic compounds, converted to organic compounds that are used as energy by autotrophs, is stored within the body of the heterotrophs called primary consumers.

    The energy carnivores can use as energy mainly comes from lipids (fats) that the herbivore has stored within its body. Small amounts of glycogen (a polysaccharide of glucose which serves as form of long term energy storage) is stored within the liver and in the muscles and can be used for energy intake by carnivores, although the supply is not abundant.

    Carnivores are usually predators, such as secondary consumers: heterotrophs which eat herbivores, such as snakes, birds and frogs (often insectivores) and marine organisms which consume zooplankton such as small fish, crabs and jellyfish. They may also be tertiary consumers, predators that eat other carnivores, such as lions, hawks, sharks, and wolves.

    Carnivores may also be scavengers, animals such as vultures or cockroaches, which eat animals which are already dead often this is the carrion (meat) of animals that has been left over from the kill of a predator.

    Fungi

    Fungi are heterotrophic organisms, although they do not ingest their food as other animals do, but feed by absorption. Fungi have root-like structures called hyphae, that grow and form a network through the substrate on which the fungi is feeding. These hyphae secrete digestive enzymes, which break down the substrate, making digestion of the nutrients possible.

    Fungi feed on a variety of different substrates, such as wood, cheese or flesh, although most of them specialize on a restricted range of food sources some fungi are highly specialized, and are only able to obtain nutrition from a single species.

    Many fungi are parasitic, which means they feed on a host without killing it. Although, most fungi are saprobic, meaning they feed from already dead or decaying material, such as leaf litter, animal carcasses and other debris. The saprobic fungi recycle the nutrients from the dead or decaying material, which becomes available as nutrients for animals that eat fungi. The role of decomposers that fungi have as recyclers at all trophic levels of the nutrient cycle is extremely important within ecosystems, although they are also highly valuable to humans economically. Many fungi are responsible for production of human food, such as yeast (Saccharomyces cerevisiae), which is used to make bread, beer and cheese. Fungi are also used as medicines, such as penicillin.


    Haematology And Haemoglobin In Blood Biology Essay

    The major function of erythrocytes is to transport oxygen and carbon dioxide in the blood. Such transport is vital for the delivery of oxygen from the lungs to respiring cells, where it is removed from the body. Erythrocytes have a high capacity for carrying oxygen and carbon dioxide because they contain in their cytoplasm two proteins Haemoglobin and carbonic anhydrase. Haemoglobin binds, and thus transports, oxygen and carbon dioxide, whereas carbonic anhydrase is essential for the transport of carbon dioxide only.

    HemoCue is a portable haemoglobinometer where any blood source can be used such as blood from a capillary, vein or an artery. The cuvette will collect the exact amount of blood and mix it with the reagents. Results appear on a screen displaying the erythrocyte count.

    The total volume of blood in a normal healthy adult is approximately 5.5 litres. About 3 litres will consist of plasma and 2.5 litres will consist of erythrocytes. Leukocytes and platelets are also included. The fractional contribution of erythrocytes to the blood volume is called the haematocrit:

    ''The haematocrit (Ht or HCT) or packed cell volume (PCV) is the proportion of blood volume that is occupied by red blood cells. It is normally about 48% for men and 38% for women.'' (Purves, William K., 2004)

    The haematocrit can be affected by factors such as erythrocyte size and number, however, in mammals haematocrit is usually independent of body size.

    A haemocytometer can be used for:

    'Counting of blood cells. specially designed slides have chambers of known depth with an etched grid on the bottom chamber.'' (Willey, J.M., 2008)

    Fig. 1: Neubauer counting chamber (haemocytometer)

    The aims of this experiment were to see and distinguish between the formed elements of blood using the light microscope and to make blood cell counts of the red blood cells (erythrocytes) in a blood sample.

    One change that occurred, that was not stated in the methods was that the blood that was used for the experiment was disposed of by washing it down the sink. Also heparinised capillary tubes were used.

    All other methods and procedures were followed as stated in the practical booklet.

    For full method, please refer to 4LFS0029, Human physiology, practical booklet, pp 14-17.

    Fig. 2: The given reference ranges for a rat, human male and human female

    Determination of red cell count (RCC)

    From the Neubauer haemocytometer, the following red cell counts were counted:

    Table 1: Results of the Neubauer haemocytometer

    Position of square in the central block

    Number of red blood cells

    The number of erythrocytes in one litre of blood = Number of cells x 1010

    Comparing this value with the standard human haematological indices, the value that has been calculated is approximately double the lower end of the standard haematological indices for the human male and female. However, comparing the value to the standard rat haematological indices, it lays closer to the lower end, although it is still within range.

    Determination of haemoglobin (Hb)

    The determination of haemoglobin was carried out via the 'Hemocue haemoglobinometer'.

    The results obtained for haemoglobin was a figure of 171g/litre.

    Comparing this value with the standard values for human blood, it is evident that the value is within the range for the human male however it lies outside of the ranges for a human female. For the range of values for a rat, the value of 171g/litre is exactly 10g/litre over the maximum range.

    Determination of haematocrit (Hct)

    The percentage of a blood sample that was occupied by the erythrocytes after centrifugation in a heparinised capillary tube was 49%. Converting this percentage to SI units:

    For human males and females this value lies within both of their ranges. The value also lies within the normal range for a rat however, it lies towards the higher end.

    Mean corpuscular Haemoglobin (MCH)

    MCH is the haemoglobin content of a single cell measured in absolute units instead of reference to an arbitrary Hb content and cell count. The following formula was used to determine MCH:

    MCH = Hb/RCC (where Hb and RCC are in SI units)

    The MCH value does not lie within either the human male or female values, it is too low. It is, however, within the range for the rat values, towards the lower end.

    Mean Cell Volume (MCV)

    The size of an erythrocyte can be calculated from the following formula:

    Mean cell volume = PCV/RCC (when PCV and RCC are in SI units)

    The figure of 71fl does not lie within the human male or female ranges, it does, however lie within the rat range.

    Mean Corpuscular Haemoglobin Concentration (MCHC)

    The MCHC is a measure of the average haemoglobin carried by a litre of blood. It can be calculated from the following formula:

    This value lies within the range for both human males and females and it also lies within the range for rats.

    Differential White Cell Count

    Microscope was set at x40 magnification. The following white blood cells were observed and their sizes were noted.

    Fig. 3: Drawings of the white blood cells observed under microscope

    Table 1 in the results section shows the results that were obtained from the Neubauer haemocytometer. A total of 687 red blood cells were counted from the five chambers. It can therefore be calculated that in one litre of the rat's blood there were 6.87 x 1012/litre blood of erythrocytes present. This figure fits well into the reference ranges for the rat however it is also evident from the figure that the amount of erythrocytes in one litre of the rat's blood is towards the lower end of the ranges. The sample of blood that was given from the rat shows that for any human male or female, the rat will always have double the amount of erythrocytes of the lower end of the human ranges.

    A figure of 171g/litre was obtained for the haemoglobin (Hb) value. This figure does not lie within either of the rat nor the human female reference ranges it does, however, lie in the reference range of the human male. The maximum amount of haemoglobin that is normal for a rat is 161 g/litre, and the figure of 171 g/litre is over the maximum. A high amount of haemoglobin could result in a condition called iron overload. This high amount of haemoglobin could be due to the rat's diet

    ''Experimental chronic iron overload was produced in rats by feeding them a chow diet'' (A J Dabbagh, T Mannion, S M lynch and B Frie)

    The above statement shows that iron overload can be produced due to what diet a rat has. The same statement could apply to a human female as the maximum normal range of haemoglobin is 165 g/litre. This could possibly be eliminated by having a healthier diet.

    After centrifugation of the rat's blood, it was determined that the haematocrit value of the rat's blood was 0.49l/l. This value fits into the rat's reference range and also into both the human male and female reference ranges. This value is, however, towards the higher end of the reference ranges in both rats and human females.

    ''Higher than normal haematocrit levels can be seen in people living at high altitudes. Dehydration produces a falsely high haematocrit that disappears when proper fluid balance is restored.'' (Harrison's Principles of Internal Medicine, McGraw-Hill, edited by Eugene Braunwald, et. al., 2001.)

    From the above, it could be concluded that the high haematocrit value for the rat is due to dehydration and its habitat. However, gender and age are also contributors to high haematocrit values, another factor to consider.

    The value of 25pg calculated for the Mean Corpuscular Haemoglobin (MCH) does not lie within the reference ranges of neither the human male nor the human female as it is too low. Concerning the rat's blood sample it did fit within the reference range, towards the lower end of the range. The mean corpuscular haemoglobin represents the weight of haemoglobin in an average erythrocyte. Lower values of mean corpuscular haemoglobin are usually diagnosed in certain types of anaemia such as microcytic and normocytic anaemia.

    The size of an erythrocyte was calculated from the mean cell volume (MCV). It was found from the results that the mean cell volume of the sample of rat's blood has 71fl of blood. This value does not match the reference ranges of the human male or female but it is within the reference range of the mouse. If 71fl was the value obtained from a human or female this would be significantly lower than the minimum range of 80 and thus they would be diagnosed with microcytosis which results in Excess EDTA which is hypertonic and can cause cellular dehydration which in turn decreases the mean cell volume and increases the mean corpuscular haemoglobin concentration.

    The mean corpuscular haemoglobin concentration is a measure of the average haemoglobin carried by a litre of blood. The value that was obtained for this calculation was 348.98 which lie well within all the reference ranges of the rat, the human male and female. The reference ranges for the rat, human male and female were of the same boundaries. Elevated MCHC is associated with Spherocytosis

    ''Spherocytosis is an auto-hemolytic anemia, characterized by the production of erythrocytes, that are sphere-shaped, rather than bi-concave disk shaped.'' Robert S. Hillman (2005).

    Normal MCHC is associated with pernicious anaemia which is caused by the inability to absorb vitamin B12.

    References - remember to put in alphabetical order

    Maton, Anthea Jean Hopkins, Charles William McLaughlin, Susan Johnson, Maryanna Quon Warner, David LaHart, Jill D. Wright (1993). Human Biology and Health. Englewood Cliffs, New Jersey, USA: Prentice Hall.

    Cindy L. Stanfield, 4th edition Principles of human physiology, benjamin cummings, international edition 2011, page 437

    Purves, William K. David Sadava, Gordon H. Orians, H. Craig Heller (2004). Life: The Science of Biology (7th ed.). Sunderland, Mass: Sinauer Associates. pp. 954.

    Willey, J.M., Sherwood, L.M. & Woolverton, C.J. (2008). Microbiology. (7th ed.). McGraw-Hill. P 128

    Biochem J. 1994 June 15 300(pt3):799-803 the effect of iron overload on rat plasma and liver oxidant status in vivo. (A J Dabbagh, T Mannion, S M lynch and B Frie)

    Harrison's Principles of Internal Medicine, McGraw-Hill, edited by Eugene Braunwald, et. al., 2001

    Robert S. Hillman Kenneth A. Ault Henry M. Rinder (2005). Hematology in clinical practice: a guide to diagnosis and management. McGraw-Hill Professional. pp. 146-150