Consciousness and the Pineal Gland The pineal gland has always held an elevated status in the records of most ancient cultures.
Short half-life corresponds to high reactivity. The one nanosecond half-life of the hydroxyl radical indicates that it is so reactive that it reacts with the first molecule it bumps into.
Ascorbate forms H2O2 on autoxidation direct combination with oxygen. Lipid peroxidation of polyunsaturated fatty acids exposed to oxygen leads to rancidity in foods. In living animal cells peroxidized membranes lose their permeability, becoming rigid, reactive and nonfunctional.
Lipid peroxidation can produce singlet oxygen, hydroperoxides and lipid epoxides. MDA is a major metabolite of arachidonic acid Aldehyde-bridge formation leads to the protein-protein cross-linking associated with lipofuscin formation.
Polyunsaturated fatty acids are more vulnerable to free radical oxidation than any other macromolecules in the body — and the sensitivity to free radical damage increases exponentially with the number of double bonds.
Animal cells contain three important enzymes to deal with the superoxide and hydrogen peroxide: A dismutase is an enzyme that catalyzes the reaction of two identical molecules to produce molecules in different oxidative states.
In the absense of SOD, two superoxide ions can spontaneously dismutate to produce hydrogen peroxide and singlet oxygen. SOD catalyzes a reaction between two superoxide ions to produce hydrogen peroxide and triplet oxygen. CAT is present in membrane-limited organelles known as peroxisomes. Glutathione is a tripeptide composed of the amino acids cysteine, glycine and glutamic acid.
Glutathione is the major antioxidant in the non-lipid portion of cells most of the cytoplasm. Reduced glutathione hydrogen donation can neutralize a hydroxyl radical: The elimination of hydrogen peroxide by glutathione can be written as the reaction: The liver, in particular, is very high in SOD.
Cellular concentration of SOD relative to metabolic activity is a very good lifespan predictor of animal species. Most mammals experience a lifetime energy expenditure ofcalories per gram, but humans have an amazingcalories per gram. Humans have the highest levels of SOD — relative to metabolic rate — of all species studied.
Oxidative damage to DNA is ten times greater in rats than in humans. Superoxide dismutase without glutathione peroxidase or catalase CAT to remove hydrogen peroxide is of little value. Insects lack glutathione peroxidase, but experiments have been performed on fruit flies made transgenic by having extra genes for SOD, CAT or both.
Radiation produces the hydroxyl radical, but most of the oxygen free radicals are byproducts of cell metabolism — particularly in the mitochondria, the lysosomes and the peroxisomes. One of the reasons these organelles are surrounded by membranes may be to protect the cell from the free-radicals they generate.
DNA may be sequestered in the nucleus, in part, as additional protection against free radicals. Nonetheless, free radicals contribute to DNA damage and mutation. In addition to enzymes, the animal cell uses many other chemicals to protect against oxygen free-radicals. Melatonina hormone produced by the pineal gland in decreasing quantities with aging, efficiently crosses membranes including the nucleus and is effective against hydroxyl radicals.
Uric acid also protects against free-radical catalysis by binding iron. Humans have higher levels of uric acid than monkeys and other mammals because humans lack the enzyme uricase. But birds typically have twice the plasma uric acid concentration as humans.Health news with a focus on fitness news, wellness coverage and living a healthy Southern California life.
Abstract. In the last two decades, the widespread application of genetic and genomic approaches has revealed a bacterial world astonishing in its ubiquity and diversity. Jun 26, · Introduction In this assignment I am going to compare some areas of molecular revolution with genomics revolution.
Cyril Darlington (ï¿½) was the most famous cytologist in the world in the decades preceding the molecular revolution of the s. A)In conclusion, stem cell research holds the answers too many of the questions that we are looking for regarding the human body.
B)New techniques will be developed that will aid in not only understanding why diseases occur, but how to cure them for good.
The Importance of Stem Cell Research - Stem cell research is a topic almost everybody in the world has a viewpoint on. Many view the issue of stem cell research and stem cell therapy as morally wrong and a crime against humanity, others view the study of stem cells as the next step in modern science.
Others thought that research on adult stem cells was less controversial than research on embryonic stem cells. Embryonic stem cell research leads to the show more content But there are many factors to where someone would donation an embryo to a clinic.