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Fructolysis
Fructolysis refers to the metabolism of fructose from dietary sources. Though the metabolism of glucose through glycolysis uses many of the same enzymes and intermediate structures as those in fructolysis, the two sugars have very different metabolic fates in human metabolism. Under one percent of ingested fructose is directly converted to plasma triglyceride. 29% - 54% of fructose is converted in liver to glucose, and about a quarter of fructose is converted to lactate. 15% - 18% is converted to glycogen. Glucose and lactate are then used normally as energy to fuel cells all over the body. Fructose is a dietary monosaccharide present naturally in fruits and vegetables, either as free fructose or as part of the disaccharide sucrose, and as its polymer inulin. It is also present in the form of refined sugars including granulated sugars (white crystalline table sugar, brown sugar, confectioner's sugar, and turbinado sugar), refined crystalline fructose, as high fructose corn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fructose And Galactose Metabolism
Fructose (), or fruit sugar, is a ketonic simple sugar found in many plants, where it is often bonded to glucose to form the disaccharide sucrose. It is one of the three dietary monosaccharides, along with glucose and galactose, that are absorbed by the gut directly into the blood of the portal vein during digestion. The liver then converts most fructose and galactose into glucose for distribution in the bloodstream or deposition into glycogen. Fructose was discovered by French chemist Augustin-Pierre Dubrunfaut in 1847. The name "fructose" was coined in 1857 by the English chemist William Allen Miller. Pure, dry fructose is a sweet, white, odorless, crystalline solid, and is the most water-soluble of all the sugars. Fructose is found in honey, tree and vine fruits, flowers, berries, and most root vegetables. Commercially, fructose is derived from sugar cane, sugar beets, and maize. High-fructose corn syrup is a mixture of glucose and fructose as monosaccharides. Sucrose is a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fructose
Fructose (), or fruit sugar, is a Ketose, ketonic monosaccharide, simple sugar found in many plants, where it is often bonded to glucose to form the disaccharide sucrose. It is one of the three dietary monosaccharides, along with glucose and galactose, that are absorbed by the gut directly into the blood of the portal vein during digestion. The liver then converts most fructose and galactose into glucose for distribution in the bloodstream or deposition into glycogen. Fructose was discovered by French chemist Augustin-Pierre Dubrunfaut in 1847. The name "fructose" was coined in 1857 by the English chemist William Allen Miller. Pure, dry fructose is a sweet, white, odorless, crystalline solid, and is the most water-soluble of all the sugars. Fructose is found in honey, tree and vine fruits, flowers, Berry, berries, and most List of root vegetables, root vegetables. Commercially, fructose is derived from sugar cane, sugar beets, and maize. High-fructose corn syrup is a mixture of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metabolism
Metabolism (, from ''metabolē'', "change") is the set of life-sustaining chemical reactions in organisms. The three main functions of metabolism are: the conversion of the energy in food to energy available to run cellular processes; the conversion of food to building blocks of proteins, lipids, nucleic acids, and some carbohydrates; and the elimination of metabolic wastes. These enzyme-catalyzed reactions allow organisms to grow and reproduce, maintain their Structures#Biological, structures, and respond to their environments. The word ''metabolism'' can also refer to the sum of all chemical reactions that occur in living organisms, including digestion and the transportation of substances into and between different cells, in which case the above described set of reactions within the cells is called intermediary (or intermediate) metabolism. Metabolic reactions may be categorized as ''catabolic''—the ''breaking down'' of compounds (for example, of glucose to pyruvate by c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gluconeogenesis
Gluconeogenesis (GNG) is a metabolic pathway that results in the biosynthesis of glucose from certain non-carbohydrate carbon substrates. It is a ubiquitous process, present in plants, animals, fungi, bacteria, and other microorganisms. In vertebrates, gluconeogenesis occurs mainly in the liver and, to a lesser extent, in the cortex of the kidneys. It is one of two primary mechanisms – the other being degradation of glycogen ( glycogenolysis) – used by humans and many other animals to maintain blood sugar levels, avoiding low levels (hypoglycemia). In ruminants, because dietary carbohydrates tend to be metabolized by rumen organisms, gluconeogenesis occurs regardless of fasting, low-carbohydrate diets, exercise, etc. In many other animals, the process occurs during periods of fasting, starvation, low-carbohydrate diets, or intense exercise. In humans, substrates for gluconeogenesis may come from any non-carbohydrate sources that can be converted to pyruvate or inter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glyceraldehyde
Glyceraldehyde (glyceral) is a triose monosaccharide with chemical formula C3 H6 O3. It is the simplest of all common aldoses. It is a sweet, colorless, crystalline solid that is an intermediate compound in carbohydrate metabolism. The word comes from combining glycerol and aldehyde, as glyceraldehyde is glycerol with one alcohol group oxidized to an aldehyde. Structure Glyceraldehyde has one chiral center and therefore exists as two different enantiomers with opposite optical rotation: * In the nomenclature, either from Latin ''Dexter'' meaning "right", or from Latin ''Laevo'' meaning "left" * In the R/S nomenclature, either R from Latin ''Rectus'' meaning "right", or S from Latin ''Sinister'' meaning "left" While the optical rotation of glyceraldehyde is (+) for ''R'' and (−) for ''S'', this is not true for all monosaccharides. The stereochemical configuration can only be determined from the chemical structure, whereas the optical rotation can only be determined em ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dihydroxyacetone
Dihydroxyacetone (; DHA), also known as glycerone, is a simple saccharide (a triose) with formula . DHA is primarily used as an ingredient in sunless tanning products. It is often derived from plant sources such as sugar beets and sugar cane, and by the fermentation of glycerin. Chemistry DHA is a hygroscopic white crystalline powder. It has a sweet cooling taste and a characteristic odor. It is the simplest of all ketoses and has no chiral center. The normal form is a dimer (2,5-bis(hydroxymethyl)-1,4-dioxane-2,5-diol). The dimer slowly dissolves in water, whereupon it converts to the monomer. These solutions are stable at pH's between 4 and 6. In more basic solution, it degrades to brown product. : This skin browning effect is attributed to a Maillard reaction. DHA condenses with the amino acid residues in the protein keratin, the major component of the skin surface. When injected, no pigmentation occurs, consistent with a role for oxygen in color development. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trioses
A triose is a monosaccharide, or simple sugar, containing three carbon atoms. There are only three possible trioses: the two enantiomers of glyceraldehyde, which are aldoses; and dihydroxyacetone, a ketose which is symmetrical and therefore has no enantiomers. Trioses are important in photosynthesis and cellular respiration. During glycolysis, fructose-1,6-bisphosphate is broken down into glyceraldehyde-3-phosphate and dihydroxyacetone phosphate. Lactic acid and pyruvic acid are later derived from these molecules. Importance of triose in animal physiology * Trioses serve as metabolic intermediates in various different metabolic pathways such as glycolysis, gluconeogenesis, and the pentose phosphate pathway. * Trioses contribute to the synthesis of essential biomolecules including lipids, amino acid Amino acids are organic compounds that contain both amino and carboxylic acid functional groups. Although over 500 amino acids exist in nature, by far the most importan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adenosine Triphosphate
Adenosine triphosphate (ATP) is a nucleoside triphosphate that provides energy to drive and support many processes in living cell (biology), cells, such as muscle contraction, nerve impulse propagation, and chemical synthesis. Found in all known forms of life, it is often referred to as the "molecular unit of currency" for intracellular energy transfer. When consumed in a Metabolism, metabolic process, ATP converts either to adenosine diphosphate (ADP) or to adenosine monophosphate (AMP). Other processes regenerate ATP. It is also a Precursor (chemistry), precursor to DNA and RNA, and is used as a coenzyme. An average adult human processes around 50 kilograms (about 100 mole (unit), moles) daily. From the perspective of biochemistry, ATP is classified as a nucleoside triphosphate, which indicates that it consists of three components: a nitrogenous base (adenine), the sugar ribose, and the Polyphosphate, triphosphate. Structure ATP consists of three parts: a sugar, an amine base ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Triglyceride
A triglyceride (from '' tri-'' and '' glyceride''; also TG, triacylglycerol, TAG, or triacylglyceride) is an ester derived from glycerol and three fatty acids. Triglycerides are the main constituents of body fat in humans and other vertebrates as well as vegetable fat. They are also present in the blood to enable the bidirectional transference of adipose fat and blood glucose from the liver and are a major component of human skin oils. Many types of triglycerides exist. One specific classification focuses on saturated and unsaturated types. Saturated fats have ''no'' C=C groups; unsaturated fats feature one or more C=C groups. Unsaturated fats tend to have a lower melting point than saturated analogues; as a result, they are often liquid at room temperature. Chemical structure The three fatty acids substituents can be the same, but they are usually different. The positions of the three fatty acids are specified using stereospecific numbering as sn-1, sn-2, and sn- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GLUT5
GLUT5 is a fructose transporter expressed on the apical border of enterocytes in the small intestine. GLUT5 allows for fructose to be transported from the intestinal lumen into the enterocyte by facilitated diffusion due to fructose's high concentration in the intestinal lumen. GLUT5 is also expressed in skeletal muscle, testis, kidney, fat tissue (adipocytes), and brain. Fructose malabsorption or Dietary Fructose Intolerance is a dietary disability of the small intestine, where the amount of fructose carrier in enterocytes is deficient. In humans the GLUT5 protein is encoded by the ''SLC2A5'' gene. Regulation Fructose uptake rate by GLUT5 is significantly reduced by diabetes mellitus, hypertension, obesity, fructose malabsorption, and inflammation. However, age-related changes in fructose intake capability are not explained by the rate of expression of GLUT5. The absorption of fructose in the simultaneous presence of glucose is improved, while sorbitol Sorbitol (), less ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GLUT4
Glucose transporter type 4 (GLUT4), also known as solute carrier family 2, facilitated glucose transporter member 4, is a protein encoded, in humans, by the ''SLC2A4'' gene. GLUT4 is the insulin-regulated glucose transporter found primarily in adipose tissues and striated muscle (skeletal and cardiac). GLUT4 is distinctive because it is predominantly stored within intracellular vesicles, highlighting the importance of its trafficking and regulation as a central area of research. The first evidence for this glucose transport protein was provided by David James in 1988. The gene that encodes GLUT4 was cloned and mapped in 1989. At the cell surface, GLUT4 permits the facilitated diffusion of circulating glucose down its concentration gradient into muscle and fat cells. Once within cells, glucose is rapidly phosphorylated by glucokinase in the liver and hexokinase in other tissues to form glucose-6-phosphate, which then enters glycolysis or is polymerized into glycogen. Glucose-6-p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GLUT1
Glucose transporter 1 (or GLUT1), also known as solute carrier family 2, facilitated glucose transporter member 1 (SLC2A1), is a uniporter protein that in humans is encoded by the ''SLC2A1'' gene. GLUT1 facilitates the transport of glucose across the plasma membranes of mammalian cells. This gene encodes a facilitative glucose transporter that is highly expressed in erythrocytes and endothelial cells, including cells of the blood–brain barrier. The encoded protein is found primarily in the cell membrane and on the cell surface, where it can also function as a receptor for human T-cell leukemia virus (HTLV) I and II. GLUT1 accounts for 2 percent of the protein in the plasma membrane of erythrocytes. During early development, GLUT1 expression is compartmentalized across different tissues, ensuring that metabolic requirements are met in a tissue-specific manner. This tissue-specific glucose metabolism is essential for regulating the differentiation of specific lineages, su ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
