SpectrophotometrySpectrophotometry is a branch of electromagnetic spectroscopy concerned with the quantitative measurement of the reflection or transmission properties of a material as a function of wavelength. Spectrophotometry uses photometers, known as spectrophotometers, that can measure the intensity of a light beam at different wavelengths. Although spectrophotometry is most commonly applied to ultraviolet, visible, and infrared radiation, modern spectrophotometers can interrogate wide swaths of the electromagnetic spectrum, including x-ray, ultraviolet, visible, infrared, and/or microwave wavelengths.
Peptide hormonePeptide hormones are hormones whose molecules are peptides. Peptide hormones have shorter amino acid chain lengths than protein hormones. These hormones have an effect on the endocrine system of animals, including humans. Most hormones can be classified as either amino acid–based hormones (amine, peptide, or protein) or steroid hormones. The former are water-soluble and act on the surface of target cells via second messengers; the latter, being lipid-soluble, move through the plasma membranes of target cells (both cytoplasmic and nuclear) to act within their nuclei.
CuvetteIn laboratories, a cuvette (French: cuvette = "little vessel") is a small tube-like container with straight sides and a circular or square cross-section. It is sealed at one end, and made of a clear, transparent material such as plastic, glass, or fused quartz. Cuvettes are designed to hold samples for spectroscopic measurement, where a beam of light is passed through the sample within the cuvette to measure the absorbance, transmittance, fluorescence intensity, fluorescence polarization, or fluorescence lifetime of the sample.
MetalA metal (from Ancient Greek μέταλλον métallon 'mine, quarry, metal') is a material that, when freshly prepared, polished, or fractured, shows a lustrous appearance, and conducts electricity and heat relatively well. Metals are typically ductile (can be drawn into wires) and malleable (they can be hammered into thin sheets). These properties are the result of the metallic bond between the atoms or molecules of the metal. A metal may be a chemical element such as iron; an alloy such as stainless steel; or a molecular compound such as polymeric sulfur nitride.
MordantA mordant or dye fixative is a substance used to set (i.e. bind) dyes on fabrics. It does this by forming a coordination complex with the dye, which then attaches to the fabric (or tissue). It may be used for dyeing fabrics or for intensifying stains in cell or tissue preparations. Although mordants are still used, especially by small batch dyers, it has been largely displaced in industry by directs. The term mordant comes from the Latin mordere, "to bite".
Coordination complexA coordination complex is a chemical compound consisting of a central atom or ion, which is usually metallic and is called the coordination centre, and a surrounding array of bound molecules or ions, that are in turn known as ligands or complexing agents. Many metal-containing compounds, especially those that include transition metals (elements like titanium that belong to the periodic table's d-block), are coordination complexes. Coordination complexes are so pervasive that their structures and reactions are described in many ways, sometimes confusingly.
PeptidePeptides are short chains of amino acids linked by peptide bonds. A polypeptide is a longer, continuous, unbranched peptide chain. Polypeptides which have a molecular mass of 10,000 Da or more are called proteins. Chains of fewer than twenty amino acids are called oligopeptides, and include dipeptides, tripeptides, and tetrapeptides. Peptides fall under the broad chemical classes of biological polymers and oligomers, alongside nucleic acids, oligosaccharides, polysaccharides, and others.
Angiotensin II receptor blockerAngiotensin II receptor blockers (ARBs), formally angiotensin II receptor type 1 (AT1) antagonists, also known as angiotensin receptor blockers, angiotensin II receptor antagonists, or AT1 receptor antagonists, are a group of pharmaceuticals that bind to and inhibit the angiotensin II receptor type 1 (AT1) and thereby block the arteriolar contraction and sodium retention effects of renin–angiotensin system. Their main uses are in the treatment of hypertension (high blood pressure), diabetic nephropathy (kidney damage due to diabetes) and congestive heart failure.
ACE inhibitorAngiotensin-converting-enzyme inhibitors (ACE inhibitors) are a class of medication used primarily for the treatment of high blood pressure and heart failure. This class of medicine works by causing relaxation of blood vessels as well as a decrease in blood volume, which leads to lower blood pressure and decreased oxygen demand from the heart. ACE inhibitors inhibit the activity of angiotensin-converting enzyme, an important component of the renin–angiotensin system which converts angiotensin I to angiotensin II, and hydrolyses bradykinin.
