1.Human Erythrocytes. Human erythrocytes have a life span of about 120 days in circulation. This life span is achieved even though they have no nuclei or internal repair mechanism and thus have no major biosynthetic repair mechanisms. Compared to other cells in the body for example neutrophils that have a life span of only 5 days (11) the human erythrocyte circulate through the body for a long period of time, a full circulation on average take about 20 seconds to complete (12). Its main function is to transport oxygen in hemoglobin to the tissues and surrounding organs. The cell can swell changing it osmotic pressure when oxygen or carbon dioxide is being transported, and can hold up too 150fL. (12) The human erythrocytes are formed through many components such as actin, spectrin and other protein that help the cell to form its shape and rigidity. Erythrocytes take up a large percentage of the overall cell population with 4-6 million of them per microliter.(12) The big issue is when the shape of the cell becomes mutated and the cell cannot carry out its normal biological process. With them being at such a high ratio in our body and their lack of a biosynthesis repair mechanism it can lead to disease’s to occur. 1.2 Mutations. 1.2.1 Sickle cell anemia. Human Erythrocytes can become misshaped due to mutations in its genetic structure. Sickle cell anemia is coursed by a single nucleotide mutation in the cells genetic structure. Specifically, in the beta chain of the hemoglobin protein, in the chain the valine is replaced with the glutamic acid. Given in the name of the disease the erythrocytes become sickle shaped and some stick together, causing blockages in values and capillaries around the body. Because of the deformed shape of... ... middle of paper ... ...dle of the spectrin tetramer. (10) The intrinsically unstructured protein β-spectrin C- terminal tail binds to the structured α-spectrin N-terminal tail. 1.9 Proteolysis. Proteolysis is the process by which a protease (enzyme) breaks down a protein into a polypeptide chain or amino acids. Proteolysis can break down proteins at a higher affinity when there in their primary structure. When proteins are folded and form a bundle the enzyme finds it difficult to attack the protein to break it down. This is why protein want to from the quaternary structure to make it less susceptible to this proteolysis attack. Stephanie A. Hill published a paper concluding: In spectrin, the alpha and beta chains are intrinsically unfolded proteins when they are not bound to one another. But when they bind together to form the tetramer in the “head to head” interaction they are fully
That means the active site and the substrate should be exactly complementary so that the substrate can fit in perfectly. Once they collide, the substrate and. some of the side-chains of the enzyme’s amino acids form a temporary. bond so that the substrate can be held in the active site. They combine to form an enzyme-substrate complex and the enzyme can start.
Hereditary spherocytosis is a disorder in the membrane of a red blood cell that causes the red blood cell to be shaped like spheres, instead of flat discs (Wint Carmella). When red blood cells start out they are shaped like flat discs. Over time when passing through the spleen pieces of the membrane are removed, causing the red blood cells to become round in shape, hence the term Spherocytosis (Seattle Childrens). When red blood cells enter the spleen the cells undergo hemolysis. Hemolysis in hereditary spherocytosis results in the interplay of an intact spleen and an intrinsic membrane protein defect (Medscape). The breakdown of red blood cells is called hemolytic anemia (Wint Carmella). A normal red blood cell can live up to one hundred and twenty days. A red blood cell with the membrane defect might live ten to thirty days. When the child d...
... the codon for the amino acid methionine is added the head of each chain.
Sickle cell anemia is a genetic disorder that erythrocytes tolerate sickle shape red blood cells. These red blood cells are easy to damage, which leads to hemolytic anemia. Abnormal hemoglobin is fragile to low oxygen conditions within the body. It loses the blood solubility, and then forms thick strands called polymers. This gives the abnormal shape, called Sickle cell.
Sickle cell anemia occurs when an abnormal form of hemoglobin (HbS) is produced. HbS molecules tend to clump together, making red blood cells sticky, stiff, and more fragile, and causing them to form into a curved, sickle shape. Red blood cells containing HbS can go back and forth between being shaped normally and being sickle shaped until they eventually become sickle shaped permanently. Instead of moving through the bloodstream easily, these sickle cells can clog blood vessels and deprive the body's tissues and organs of the oxygen they need to stay healthy.
The problem is that when a red blood cell with hemoglobin S releases oxygen, the cell changes from the usual doughnut shape to a sickle or S shape, and becomes stiff rather than soft and flexible like normal red blood cells. This "sickled cell," which resembles a crescent moon, can't continue to glide through the small blood vessels as usual. Instead, it gets stuck in the tiny blood vessels, blocking the flow of blood and causing pain.
RBC membrane disorders consist of HS where it is identified by the diversity in clinic and laboratory which is also revealed by recent molecular studies. A mutation is found in one of the spherocytosis genes causing erythrocyte membrane defects. The Laparoscopic approach has been one of the new surgical procedures for splenectomy for the treatment of HS. Partial splenectomy is done in children to avoid post-splenectomy sepsis. The latest management helps in understanding the protocol of splenectomy and suggest a meticulous discussion between the patient, the family and the healthcare provider. Hereditary Spherocytosis (HS) or Minkowski–Chauffard syndrome is a genetic familial haemolytic condition which causes defects in the internal cytoskeleton of erythrocytes membrane leading to anaemia. The cells have sphere-like shape instead of bi-concave lacking flexibility; hence it becomes more susceptible to haemolysis as they cannot pass through the vessels without changing their shapes. According tothe genetic defect is caused by the heterogeneous modification in one of the six genes, which encodes for the protein involved in vertical associations that tie the cell membrane skeleton to the lipid-bilayer. The erythrocyte membrane skeleton defects are responsible for different hereditary haemolytic anaemia’s associated with the abnormal shape of the erythrocytes. Haemoglobin is released due to haemolysis. There are more reticulocytes present in the circulation and bone marrow tries to produce more RBC than usual in order to prevent anaemia
Sickle cell anemia is a blood disorder that is inherited from both parents in which the body produces abnormally shaped red blood cells. In sickle cell anemia, the hemoglobin in red blood cells links together; resulting in the red blood cells to become rigid and a C-shaped. These deformed cells block blood and oxygen flow in blood vessels. Sickle cells deteriorate quicker than normal red blood cells, which results in anemia.
A patient with sickle cell has inherited the condition from both parents, and it all starts in the hemoglobin. Hemoglobin is “an iron-containing protein in red blood cells that reversibly binds to oxygen” (Reece, Urry, Cain, Wasserman, Minorsky, & Jackson, 2011). Obviously, hemoglobin is an important substance for oxygen to be transported in red blood cells. However, a patient with sickle cell has irregular hemoglobin cause by inherited genes. This “oxygen delivery” system cannot function properly because a gene
Sickle cell anemia is the most common in hemoglobin mutation diseases due to mutation to beta-blobin gene. The substitution of valine for glutamate at position 6 of the beta chains paces a nonpolar residue on the outside of hemoglobin S. the oxygen affinity and allosteric properties of hemoglubin are virtually unaffected by this changes. However, this alternation markedly reduces the solubility of the deoxygenated but not the oxygenated form of hemoglobin. Thus, sicking occurs when there is a high concentration of the deoxygenated form of hemoglobin.
"The Species of the Secondary Protein Structure. Virtual Chembook - Elmhurst College. Retrieved July 25, 2008, from http://www.cd http://www.elmhurst.edu/chm/vchembook/566secprotein.html Silk Road Foundation. n.d. - n.d. - n.d.
When eaten, protein is broken down into amino acids. Proteins and amino acids are used for almost every metabolic process in the body, and are the building blocks for every tissue in your body.
A polypeptide chain is a series of amino acids that are joined by the peptide bonds. Each amino acid in a polypeptide chain is called a residue. It also has polarity because its ends are different. The backbone or main chain is the part of the polypeptide chain that is made up of a regularly repeating part and is rich with the potential for hydrogen-bonding. There is also a variable part, which comprises the distinct side chain. Each residue of the chain has a carbonyl group, which is good hydrogen-bond acceptor, and an NH group, which is a good hydrogen-bond donor. The groups interact with the functional groups of the side chains and each other to stabilize structures. Proteins are polypeptide chains that have 500 to 2,000 amino acid residues. Oligopeptides, or peptides, are made up of small numbers of amino acids. Each protein has a precisely defined, unique amino acid sequence, referred to as its primary structure. The amino acid sequences of proteins are determined by the nucleotide sequences of genes because nucleotides in DNA specify a complimentary sequence in RNA, which specifies the amino acid sequence. Amino acid sequences determine the 3D structures of proteins. An alteration in the amino acid sequence can produce disease and abnormal function. All of the different ways
Polycythaemia is a blood disorder defined as an increase in blood erythrocyte concentration. Absolute polycythaemia is where this increase is caused by greater erythrocyte production, determined by measuring the haematocrit level, with one study showing that 83% of sufferers have a haematocrit level of >55%. This should not be confused with relative polycythaemia, caused by a decrease in blood plasma volume often secondary to hypertension. Interestingly, those affected tend to also have increased blood platelet and white cell concentrations, which correlates well with the notion that the disease is caused by a genetic defect in the haematopoietic stem cell population within the bone marrow. Studies have shown the median age of onset to be 60, although a Mayo Clinic study in Olmstead County, Minnesota showed it to be slightly higher, at between 70 and 79 years, with men affected more than women – though the reason behind the gender inequality is currently unknown. In addition, its prevalence within the US is thought to be in the region of 50/100,000. Furthermore, it has long been known that Finnish skier and seven time Olympic champion Eero Mantyranta suffered from the disease, and it is often stated that his success, at least in part, can be put down to his polycythaemia – indeed experiments have shown that it can increase the blood oxygen carrying capacity by up to 50%, an undeniable asset to any endurance athlete. However, the disease can also prove fatal in many cases because the thickened blood increases the probability of clot formation, giving deep vein thrombosis and potentially pulmonary embolus. It is this double edged nature of polycythaemia that first took ...
"Within a single subunit [polypeptide chain], contiguous portions of the polypeptide chain frequently fold into compact, local semi-independent units called domains." - Richardson, 1981