|
Na–K–Cl Cotransporter
The Na–K–Cl cotransporter (NKCC) is a transport protein that aids in the secondary active transport of sodium, potassium, and chloride into cells. In humans there are two isoforms of this membrane transport protein, NKCC1 and NKCC2, encoded by two different genes (''SLC12A2'' and ''SLC12A1'' respectively). Two isoforms of the NKCC1/Slc12a2 gene result from keeping (isoform 1) or skipping (isoform 2) exon 21 in the final gene product. NKCC1 is widely distributed throughout the human body; it has important functions in organs that secrete fluids. In contrast, NKCC2 is found specifically in the kidney, where it extracts sodium, potassium, and chloride from the urine so they can be reabsorbed into the blood. Function NKCC proteins are membrane transport proteins that transport sodium (Na), potassium (K), and chloride (Cl) ions across the cell membrane. Because they move each solute in the same direction, they are considered symporters. They maintain electroneutrality by m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Symporter
A symporter is an integral membrane protein that is involved in the transport of two (or more) different molecules across the cell membrane in the same direction. The symporter works in the plasma membrane and molecules are transported across the cell membrane at the same time, and is, therefore, a type of cotransporter. The transporter is called a symporter, because the molecules will travel in the same direction in relation to each other. This is in contrast to the antiport transporter. Typically, the ion(s) will move down the electrochemical gradient, allowing the other molecule(s) to move against the concentration gradient. The movement of the ion(s) across the membrane is facilitated diffusion, and is coupled with the active transport of the molecule(s). In symport, two molecule move in a 'similar direction' at the 'same time'. For example, the movement of glucose along with sodium ions. It exploits the uphill movement of other molecules from low to high concentration, whi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Basolateral Membrane
The cell membrane (also known as the plasma membrane or cytoplasmic membrane, and historically referred to as the plasmalemma) is a biological membrane that separates and protects the interior of a cell from the outside environment (the extracellular space). The cell membrane consists of a lipid bilayer, made up of two layers of phospholipids with cholesterols (a lipid component) interspersed between them, maintaining appropriate membrane fluidity at various temperatures. The membrane also contains membrane proteins, including integral proteins that span the membrane and serve as membrane transporters, and peripheral proteins that loosely attach to the outer (peripheral) side of the cell membrane, acting as enzymes to facilitate interaction with the cell's environment. Glycolipids embedded in the outer lipid layer serve a similar purpose. The cell membrane controls the movement of substances in and out of a cell, being selectively permeable to ions and organic molecul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Exocrine Gland
Exocrine glands are glands that secrete substances onto an epithelial surface by way of a duct. Examples of exocrine glands include sweat, salivary, mammary, ceruminous, lacrimal, sebaceous, prostate and mucous. Exocrine glands are one of two types of glands in the human body, the other being endocrine glands, which secrete their products directly into the bloodstream. The liver and pancreas are both exocrine and endocrine glands; they are exocrine glands because they secrete products—bile and pancreatic juice—into the gastrointestinal tract through a series of ducts, and endocrine because they secrete other substances directly into the bloodstream. Exocrine sweat glands are part of the integumentary system; they have eccrine and apocrine types. Classification Structure Exocrine glands contain a glandular portion and a duct portion, the structures of which can be used to classify the gland. * The duct portion may be branched (called compound) or unbranched (called sim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Loop Diuretic
Loop diuretics are pharmacological agents that primarily inhibit the Na-K-Cl cotransporter located on the luminal membrane of cells along the thick ascending limb of the loop of Henle. They are often used for the treatment of hypertension and edema secondary to congestive heart failure, liver cirrhosis, or chronic kidney disease. While thiazide diuretics are more effective in patients with normal kidney function, loop diuretics are more effective in patients with impaired kidney function. Mechanism of action Loop diuretics are 90% bonded to proteins and are secreted into the proximal convoluted tubule through organic anion transporter 1 (OAT-1), OAT-2, and ABCC4. Loop diuretics act on the Na+-K+-2Cl− symporter (NKCC2) in the thick ascending limb of the loop of Henle to inhibit sodium, chloride and potassium reabsorption. This is achieved by competing for the Cl− binding site. Loop diuretics also inhibit NKCC2 at macula densa, reducing sodium transported into macula ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bumetanide
Bumetanide, sold under the brand name Bumex among others, is a medication used to treat swelling and high blood pressure. This includes swelling as a result of heart failure, liver failure, or kidney problems. It may work for swelling when other medications have not. For high blood pressure it is not a preferred treatment. It is taken by mouth, or by injection into a vein or muscle. Effects generally begin within an hour and last for about six hours. Common side effects include dizziness, low blood pressure, low blood potassium, muscle cramps, and kidney problems. Other serious side effects may include hearing loss and low blood platelets. Blood tests are recommended regularly for those on treatment. Safety during pregnancy and breastfeeding is unclear. Bumetanide is a loop diuretic and works by decreasing the reabsorption of sodium by the kidneys. Bumetanide was patented in 1968 and came into medical use in 1972. It is on the World Health Organization's List of Essentia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mutagenesis (molecular Biology Technique)
Mutagenesis () is a process by which the genetic information of an organism is changed by the production of a mutation. It may occur spontaneously in nature, or as a result of exposure to mutagens. It can also be achieved experimentally using laboratory procedures. A mutagen is a mutation-causing agent, be it chemical or physical, which results in an increased rate of mutations in an organism's genetic code. In nature mutagenesis can lead to cancer and various heritable diseases, and it is also a driving force of evolution. Mutagenesis as a science was developed based on work done by Hermann Joseph Muller, Hermann Muller, Charlotte Auerbach and J. M. Robson in the first half of the 20th century. History DNA may be modified, either naturally or artificially, by a number of physical, chemical and biological agents, resulting in mutations. Hermann Joseph Muller, Hermann Muller found that "high temperatures" have the ability to mutate genes in the early 1920s, and in 1927, demonstrated ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
N-terminus
The N-terminus (also known as the amino-terminus, NH2-terminus, N-terminal end or amine-terminus) is the start of a protein or polypeptide, referring to the free amine group (-NH2) located at the end of a polypeptide. Within a peptide, the amine group is bonded to the carboxylic group of another amino acid, making it a chain. That leaves a free carboxylic group at one end of the peptide, called the C-terminus, and a free amine group on the other end called the N-terminus. By convention, peptide sequences are written N-terminus to C-terminus, left to right (in LTR writing systems). This correlates the translation direction to the text direction, because when a protein is translated from messenger RNA, it is created from the N-terminus to the C-terminus, as amino acids are added to the carboxyl end of the protein. Chemistry Each amino acid has an amine group and a carboxylic group. Amino acids link to one another by peptide bonds which form through a dehydration reaction that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
C-terminus
The C-terminus (also known as the carboxyl-terminus, carboxy-terminus, C-terminal tail, carboxy tail, C-terminal end, or COOH-terminus) is the end of an amino acid chain (protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residue (biochemistry), residues. Proteins perform a vast array of functions within organisms, including Enzyme catalysis, catalysing metab ... or polypeptide), terminated by a free carboxyl group (-COOH). When the protein is translated from messenger RNA, it is created from N-terminus to C-terminus. The convention for writing peptide sequences is to put the C-terminal end on the right and write the sequence from N- to C-terminus. Chemistry Each amino acid has a carboxyl group and an amine group. Amino acids link to one another to form a chain by a dehydration reaction which joins the amine group of one amino acid to the carboxyl group of the next. Thus polypeptide chains have an end with an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Messenger RNA
In molecular biology, messenger ribonucleic acid (mRNA) is a single-stranded molecule of RNA that corresponds to the genetic sequence of a gene, and is read by a ribosome in the process of synthesizing a protein. mRNA is created during the process of transcription, where an enzyme (RNA polymerase) converts the gene into primary transcript mRNA (also known as pre-mRNA). This pre-mRNA usually still contains introns, regions that will not go on to code for the final amino acid sequence. These are removed in the process of RNA splicing, leaving only exons, regions that will encode the protein. This exon sequence constitutes mature mRNA. Mature mRNA is then read by the ribosome, and the ribosome creates the protein utilizing amino acids carried by transfer RNA (tRNA). This process is known as translation. All of these processes form part of the central dogma of molecular biology, which describes the flow of genetic information in a biological system. As in DNA, genetic inf ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transmembrane Protein
A transmembrane protein is a type of integral membrane protein that spans the entirety of the cell membrane. Many transmembrane proteins function as gateways to permit the transport of specific substances across the membrane. They frequently undergo significant conformational changes to move a substance through the membrane. They are usually highly hydrophobic and aggregate and precipitate in water. They require detergents or nonpolar solvents for extraction, although some of them ( beta-barrels) can be also extracted using denaturing agents. The peptide sequence that spans the membrane, or the transmembrane segment, is largely hydrophobic and can be visualized using the hydropathy plot. Depending on the number of transmembrane segments, transmembrane proteins can be classified as single-pass membrane proteins, or as multipass membrane proteins. Some other integral membrane proteins are called monotopic, meaning that they are also permanently attached to the membrane, b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 important are the 22 α-amino acids incorporated into proteins. Only these 22 appear in the genetic code of life. Amino acids can be classified according to the locations of the core structural functional groups ( alpha- , beta- , gamma- amino acids, etc.); other categories relate to polarity, ionization, and side-chain group type ( aliphatic, acyclic, aromatic, polar, etc.). In the form of proteins, amino-acid '' residues'' form the second-largest component (water being the largest) of human muscles and other tissues. Beyond their role as residues in proteins, amino acids participate in a number of processes such as neurotransmitter transport and biosynthesis. It is thought that they played a key role in enabling life on Earth and its emergence. Amino acids are formally named by the IUPAC- IUBMB Joint Commi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
