Ursharona's List: biochemistry

• 70 kilodalton heat shock proteins (Hsp70s) are a family of ubiquitously expressed heat shock proteins.
• he Hsp70s are an important part of the cell's machinery for protein folding, and help to protect cells from stress.

• in a partially-folded state.

   

  Hsp70 proteins can act to protect cells from thermal or oxidative stress. These stresses normally act to damage proteins, causing partial unfolding and possible aggregation. By temporarily binding to hydrophobic residues exposed by stress, Hsp70 prevents these partially-denatured proteins from aggregating, and allows them to refold. Low ATP is characteristic of heat shock and sustained binding is seen as aggregation suppression, while recovery from heat shock involves substrate binding and nucleotide cycling. In a thermophile ana
• HSP 70 is overexpressed in malignant melanoma^[10] and underexpressed in renal cell cancer.

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• fatty acid is a carboxylic acid with a long aliphatic tail (chain), which is either saturated or unsaturated.
• Fatty acids are important sources of fuel because, metabolized, they yield large quantities of ATP
• The brain cannot use fatty acids as a source of fuel; it relies on glucose or ketone bodies

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• Glucose-6-phosphate dehydrogenase deficiency is an X-linked recessive hereditary disease characterised by abnormally low levels of glucose-6-phosphate dehydrogenase
• a metabolic enzyme involved in the pentose phosphate pathway, especially important in red blood cell metabolism.
• G6PD deficiency is the most common human enzyme defec
• Individuals with the disease may exhibit nonimmune hemolytic anemia in response to a number of causes, most commonly infection or exposure to certain medications or chemicals
• G6PD deficiency is closely linked to favism, a disorder characterized by a hemolytic reaction to consumption of broad beans, with a name derived from the Italian name of the broad bean (fava).
• not all people with G6PD deficiency will manifest a physically observable reaction to consumption of broad beans.
• Symptomatic patients are almost exclusively male, due to the X-linked pattern of inheritance, but female carriers can be clinically affected due to unfavorable Lyonization, where random inactivation of an X-chromosome in certain cells creates a population of G6PD-deficient red blood cells coexisting with normal red cells.
• female with one affected X chromosome will show the deficiency in approximately half of her red blood cells
• in rare cases, including double X deficiency, the ratio can be much more than half, making the individual almost as sensitive as a male.
• Abnormal red blood cell breakdown (hemolysis) in G6PD deficiency can manifest in a number of ways
• Sulfonamides (such as sulfanilamide, sulfamethoxazole and mafenide), thiazolesulfone, methylene blue and naphthalene should also be avoided by people with G6PD deficiency, as should certain analgesics (such as aspirin, phenazopyridine and acetanilide) and a few non-sulfa antibiotics (nalidixic acid, nitrofurantoin, isoniazid, dapsone, and furazolidone)

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• A dehydrogenase (also called DHO in the literature) is an enzyme that oxidises a substrate by a reduction reaction that transfers one or more hydrides (H⁻) to an electron acceptor, usually NAD⁺/NADP⁺ or a flavin coenzyme such as FAD or FMN.

• Heme oxygenase or haem oxygenase (HO) is an enzyme that catalyzes the degradation of heme.
• produces biliverdin, iron, and carbon monoxide.

• Chymotrypsin is a digestive enzyme that can perform proteolysis.

• Hepcidin functions to increase iron storage in cells, thereby preventing an organism from losing too much iron
• Hepcidin inhibits iron transport by binding to the iron channel ferroportin, which is located on the basolateral surface of gut enterocytes and the plasma membrane of reticuloendothelial cells (macrophages)
• Inhibiting ferroportin shuts off the iron transport out of these cells, which store iron
• Beta-thalassemia is one of the most common congenital anemias arising from partial or complete lack of β-globin synthesis.
• Excessive iron absorption is one of the main features of β-thalassemia and can lead to severe morbidity and mortality.
• The overload of iron is associated with low levels of hepcidin.
• patients with β-thalassemia also have low hepcidin levels.
• concentration of hepcidin is increasing in the body of such patients might be therapeutic, limiting iron overload

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• Heinz bodies (also referred to as "Heinz-Ehrlich bodies") are inclusions within red blood cells composed of denatured hemoglobin.^[
• Heinz bodies are formed by damage to the hemoglobin component molecules, usually through oxidant damage, or from an inherited mutation
• several pathways leading to the hemoglobin damage.
• NADPH deficiency
• G6PD (Glucose-6-Phosphate Dehydrogenase) deficiency
• Heinz bodies can also be found in chronic liver disease
• Alpha-thalassemia - Normal adult hemoglobin is composed of two alpha and two beta chains. Alpha thalassemia patients have partial or complete defects in alpha globin production, leading to a relative abundance of beta globin chains in the cell. These excess beta globin chains aggregate to form HbH, which has decreased solubility and precipitates in the red blood cell cytoplasm.

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• with thalassemia also show an increased number and higher degree activity of neutrophil elastase, which can effect other possible comorbidities such as alpha 1 antitrypsin deficiency.

• The concentration of ferritin has been shown to increase in response to stresses such as anoxia;^[16] this implies that it is an acute phase protein.

• It has the high-energy phosphate bond found (-61.9 kJ/mol) in living organisms, and is involved in glycolysis and gluconeogenesis.
• formed by the action of the enzyme enolase on 2-phosphoglycerate.
• Metabolism of PEP to pyruvate by pyruvate kinase (PK) generates 1 molecule of adenosine triphosphate (ATP) via substrate-level phosphorylation.
• PEP is formed from the decarboxylation of oxaloacetate and hydrolysis of one guanosine triphosphate molecule

• reaction is catalyzed by the enzyme phosphoenolpyruvate carboxykinase (PEPCK). This reaction is a rate-limiting step in gluconeogenesis:^[1]

   

   

  GTP + oxaloacetate → GDP + phosphoenolpyruvate + CO₂

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• a compound with a functional group that contains a carbon-nitrogen double bond with the nitrogen atom connected to an aryl or alkyl group, not hydrogen.
• Schiff base is synonymous with azomethine
• Some restrict the term to the secondary aldimines (azomethines where the carbon is connected to a hydrogen atom), thus with the general formula RCH=NR
• chain on the nitrogen makes the Schiff base a stable imine. A Schiff base derived from an aniline, where R³ is a phenyl or a substituted phenyl, can be called an anil

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• Phosphocreatine, also known as creatine phosphate or PCr (Pcr), is a phosphorylated creatine molecule that serves as a rapidly mobilizable reserve of high-energy phosphates in skeletal muscle and brain.
• formed from parts of three amino acids: arginine (Arg), glycine (Gly), and methionine (Met).
• Phosphocreatine is synthesized in the liver and transported to the muscle cells, via the bloodstream, for storage.
• The creatine phosphate shuttle facilitates transport of high energy phosphate from mitochondria.
• Phosphocreatine can anaerobically donate a phosphate group to ADP to form ATP during the first 2 to 7 seconds following an intense muscular or neuronal effort

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• The iron ion may be either in the Fe²⁺ or in the Fe³⁺ state, but ferrihemoglobin (methemoglobin) (Fe³⁺) cannot bind oxygen.^[25] In binding, oxygen temporarily and reversibly oxidizes (Fe²⁺) to (Fe³⁺) while oxygen temporally turns into superoxide, thus iron must exist in the +2 oxidation state to bind oxygen. If superoxide ion associated to Fe³⁺ is protonated the hemoglobin iron will remain oxidized and incapable to bind oxygen. In such cases, the enzyme methemoglobin reductase will be able to eventually reactivate methemoglobin by reducing the iron center.

• Electronegativity, symbol χ (the Greek letter chi), is a chemical property that describes the tendency of an atom or a functional group to attract electrons (or electron density) towards itself
• is affected by both its atomic number and the distance that its valence electrons reside from the charged nucleus
• In general, the greater the difference in electronegativity between two atoms, the more polar the bond that will be formed between them, with the atom having the higher electronegativity being at the negative end of the dipole

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