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14

Hemoglobin molecules used to manufacture these products are not contained by a red cell membrane, and when released into the vasculature, these molecules rapidly scavenge nitric oxide.This can result in systemic vasoconstriction, decreased blood flow, increased release of proinflammatory mediators and potent vasoconstrictors, and a loss of ...


14

Red blood cells are produced in the red marrow which... "is found mainly in the flat bones, such as the pelvis, sternum, cranium, ribs, vertebrae and scapulae, and in the cancellous ("spongy") material at the epiphyseal ends of long bones such as the femur and humerus." - Wikipedia So you are partly right; the femur is associated with red blood ...


9

Snails, like most molluscs, have a protein called hemocyanin dissolved directly in the hemolymph ("blood"). Hemocyanins are copper-containing metalloproteins: the binding site for a single O2 molecule contains two copper atoms. Unlike hemoglobin, where reversible oxygen binding is accomplished without a change in the oxidation state of the Fe(II) atoms in ...


8

The "purest of all blood" is fresh out of the bone marrow, i.e. in your circulatory system. Menstrual blood is a combination of blood, some mucous, and dead endometrial tissue. The endometrium consists of a single layer of columnar epithelium resting on the stroma, a layer of connective tissue that varies in thickness according to hormonal influences. ...


7

A few components to my answer. Red blood cells do not contain a nucleus, therefore, they do not harbour DNA. The major determinant of blood compatibility is the blood antigen. There are only 4 types: O, A, B, AB. This is genetically encoded, and is expressed as a set of sugar coats on the blood cell membrane. However, the enzymes that encode for A or B ...


6

This is a well worded question. There are more reasons than the following but the most apparent is hemoglobin production and its transport. The erythrocyte is a cell whose structure is optimal for its function-the production and transport of hemoglobin. It lacks a nucleus and organelles so that it can devote almost 100% of its energy to hemoglobin ...


6

Reticulocyte stage is when the ribosomes are still present and after that no new protein synthesis occurs. However RBCs have a lot of proteins and major proteins other than haemoglobin are cytoskeletal proteins and ion channels/pumps (In fact, cytoskeletal proteins are more abundant than haemoglobin). It is the Na+-K+-ATPase that consumes most ATP. As you ...


5

No. Nobody considers red blood cells to be prokaryotic, perhaps most importantly because they are part of a eukaryotic organism. Red blood cells begin life with the full complement of organelles, including a nucleus and mitochondria, but our RBCs shed their organelles during maturation. In actuality, though, only mammalian RBCs lack nuclei; other animals' ...


5

The molecular basis of copper-transport diseases in Trends in Molecular Medicine, Volume 7, Issue 2, 1 February 2001, Pages 64–69, has a link to a 1973 paper by JM Gillespie entitled "Keratin Structure and Changes with Copper Deficiency," stating Menkes patients are often diagnosed from their unusual hair structure – termed pili torti – also known as ...


5

The reason why blood is red is rather simple: It is the iron atom in the middle of the heme, which plays the central part in binding oxygen. Depending on the oxidation state the blood looks either dark or light red. The structure is the following (taken from here): That the color only depends on the coordinated metal atom is shown by another related ...


4

The model used by Jamshidi et al. can be found in the BioModels database with acession no. MODEL1103210001 http://www.ebi.ac.uk/compneur-srv/biomodels-main/MODEL1103210001 A more recent model has also been described in Bordbar et al. iAB-RBC-283: A proteomically derived knowledge-base of erythrocyte metabolism that can be used to simulate its physiological ...


4

Well, it turns out the situation is more complex. I had assumed the answer was what rwst suggests or something to do with osmotic pressure. It seems that we don't really know that well. In a paper from 1991, Chi and Wu suggest the following possible mechanisms : Membrane fusion during the shedding of exovesicles might produce a transient decrease of the ...


4

It happens, but it is very rare. Anti-A and Anti-B antibodies are IgM type. They do no cross the placenta. Sometimes IgG can be produced and lead to the hemolytic disease of the newborn. Anti-D antibodies are IgG type and can pass through the placenta.


4

The trick for the stem cells lies in the way the proliferate and differentiate. See the image (from the reference 1): Stem cells have the problem that they need to differentiate and maintain their population at the same time (subfigure a). This can either be done by asymmetric cell division which leads to one daughter which is still a stem cell and one ...


4

Actually there are such particles. It is estimated that about 20% of the hemoglobin (HGB hereafter) is in HGB vesicles (HbV hereafter) formed by RBCs. So sure, it is possible to use small particles instead of RBCs, but these vesicles have major and minor antigens on their surface. According to some of the articles they cause other complications too by blood ...


3

The blood type of people is determined by proteins which are anchored into the surface of the red blood cells. Cells can either express the A, B, A and B or no marker, resulting in the blood groups A, B, AB and 0. People which have a certain blood type (for example A) have antibodies against the other blood type (in this case B). This will lead to the ...


3

Currently impossible to give a definite answer... It depends what altitude you look at. Going from @Alan_boyd's answer the normal range is 40-50% for males and 36-44% for females. If the altitude at which a person is acclimatized to correlates well with red blood cell count (RBCC), and this effect is not gender specific (i.e. both sexes are affected ...


3

They are recycled, the iron and other components are broken down and then absorbed. Adaptations of the RBC prevent the same RBC being used. They lack a nucleus to make them highly efficient oxygen carriers (pack as much haemoglobin as possible). Without a nucleus and other organelles they're unable to synthesise the stuff they'd need for renewal. There's a ...


3

Because one's DNA doesn't have to exactly match another person at all 3 billion locations for the transfusion to be successful. As it turns out, there are only a few proteins that determine whether a person's blood is a match to someone else's. And as it turns out, in the vast majority of the human population, there are only three alleles of the ABO gene, ...


3

The spleen is not the only organ which removes "old" erythrocytes, this happens as well in the liver and the lymph nodes. The whole process is termed Eryptosis, the Apoptosis of Erythrocytes. During the aging of erythrocytes sialic acid on their outer membrane surface is removed. This leads to the recognition by macrophages and phagocytosis of this cells by ...


2

It is critical for you to realize that one's DNA is not the determining factor when it comes to a blood transfusion. Rather, what you have to look at is the proteins being expressed by the DNA coding for blood-associated proteins, as it is these proteins that are the determinant of blood acception or rejection.In other words, the key question is whether or ...


2

Low density lipoproteins can be taken up by the macrophages under a number of circumstances (typically high circulating levels is the most important). These macrophages are called foam cells. The macrophage can then die and deposit this cholesterol and fatty material onto a vessel wall in the context of atherosclerosis. Additionally tissue damage as a result ...


2

I think the quoted answer is correct. First, the probability of getting a son( and not a daughter) is $P_s=0.5$. Next, since both the parents are heterozygous, the probability of genotype $hh$ is $P_h=0.25$. This genotype will not produce any antigen precursor, and hence there will be no antigens on RBC. As blood group O is defined by the absence of ...


2

if mother is O- That means: group O in ABO system: anti-A and anti-B antibodies group Rh- in Rh system: no D antigen and no ant-D antibodies unless previously senzitized baby is any +ve blood group other than O+ ABO system: A, B or both antigens present Rh system: D antigen present So, the mother has anti-A and anti-B antibodies and her ...


2

According to the MedlinePlus site these are the normal ranges for haematocrit: Male: 40.7 - 50.3% Female: 36.1 - 44.3% Unfortunately it isn't clear if these ranges are for people living at low altitude, but since most people in the USA do, I think this is a safe inference. So clearly there is already some overlap. The paper accessible here reports ...


2

Yes, stem cells can pass through blood vessels and capillaries (as @WYSIWYG points, these cells should be small enough to fit inside that capillary). The interesting thing is that they posses multiple mechanisms of transmigration. They are attracted by TNF-alpha activated endothelial cells [1] and can pass through by [1]: leukocyte-like diapedesis ...


2

The main regulatory input into erythrocyte production is hypoxia. The response to elevated CO2 levels in the blood (hypercapnia) is mainly to increase ventilation (i.e. more and/or deeper breaths) so that the excess can be "blown off". I think that some carbon dioxide could pass into the bloodstream from the stomach since gases tend to be quite good at ...


2

This is really google qestion. For some blood types, evolution and environmental selective pressures are clearly important for their persistence. For example, the Duffy blood type includes a receptor that allows certain types of malarial parasites to enter the red cell. Thus, in some malarial areas of Africa, populations with Duffy-negative blood ...


1

This is not an answer to the question, but tangent comments that might be useful for how you look at the problem (and too long for a comment). First, for a question like this it is useful to look at other solutions to the same problem. For instance, the second most common molecule for oxygen transport is Hemocyanin, and this is not bound to cells but is ...


1

What determines blood types is the type of antigens found on the surface of the blood. A blood cells have A antigens on their surface, B has B antigens, AB has both, and O has no antigens. What is an antigen? According to Wikipedia: an antigen (Ag), or antibody generator, is any substance which provokes an adaptive immune response. An antigen is a ...



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