compound

Xylem

...e most of their strength from lignin , a chemical compound produced only by plants. Contents showTocToggle("show","hide") 1 Structure 2 Contents 3 Mechanism 4 Reference Structure Xylem (in angiosperms ) is composed of vessel elements and tracheids ( gymnosperm xylem consi...

Redox

...not occur without the other; electrons lost by one compound must be gained by another. Contents showTocToggle("show","hide") 1 Oxidizing and Reducing agents 2 Former meaning (Oxygen/Hydrogen) 3 Examples of redox reactions 3.1 Other examples 4 Redox reactions in biology 5 S...

Pyrimidine

...yrimidine is a heterocyclic aromatic organic compound , which is similar to benzene and pyridine and that contains two nitrogen atoms at positions 1 and 3 of the six-membered ring. Three nucleobases found in nucleic acids , namely cytosine , thymine , and uracil , are pyrimidine derivative...

Purine

... Purine is a heterocyclic aromatic organic compound , consisting of a pyrimidine ring fused to an imidazole ring. The general term purines also refers to substituted purines and their tautomers . Two of the bases in nucleic acids , adenine and guanine , are purines. In DNA , these bases...

Protein

...ent ) is a complex, high molecular weight organic compound that consists of amino acids joined by peptide bonds . Proteins are essential to the structure and function of all living cells and viruses .Many proteins are enzymes or subunits of enzymes. Other proteins play structural or mechanical rol...

Photolysis

...ysis refers to any chemical reaction in which a compound is broken down by light . Photolysis is a part of photosynthesis , which occurs in the granum of the chloroplast . In photolysis the light absorbed by the chlorophyll is turned into chemical energy which is used to split water into hydr...

Redox

...not occur without the other; electrons lost by one compound must be gained by another. Contents showTocToggle("show","hide") 1 Oxidizing and Reducing agents 2 Former meaning (Oxygen/Hydrogen) 3 Examples of redox reactions 3.1 Other examples 4 Redox reactions in biology 5 S...

Microscope

...e A simple microscope , as opposed to a standard compound microscope (see below) with multiple lenses, is a ...pound optical microscope The diagrams below show compound microscopes . In its simplest form—as used by Robert Hooke , for example—the compound m...

Malaria

... (specifically Artemisia annua ), containing the compound artemisinin , a substance unrelated to the quinine derivatives, offer some future promise. Prospects of disease control Vaccines for malaria are under development, with no completely effective vaccine yet available (as of November 2004 ). A te...

Louis Pasteur

...re of tartaric acid ( 1849 ). A solution of this compound derived from living things (specifically, wine lees) rotated the plane of polarization of light passing through it. The mystery was that tartaric acid derived by chemical synthesis had no such effect, even though its reactions were identical and ...

Leaf

...rated along a main or secondary vein. Palmately compound leaves have the leaflets radiating from the end o... (hemp) and Aesculus (buckeyes). Pinnately compound leaves have the leaflets arranged along the main or mid-vein (called a rachis in this case). o...

Equilibrium

... resulting in no net change in the amount of each compound . Mechanical equilibrium , also known as static equilibrium , the state of a body at rest or in uniform motion in which the sum of all forces and torques acting on the body equals zero. Physical balance of humans and animals is maint...

Ethyl alcohol

...rain alcohol , is a flammable, colorless chemical compound , one of the alcohols that is most often found i...lic beverages . Its isolation as a relatively pure compound was probably achieved first by Islamic alchemists who developed the art of distillation , such as...

Enzyme

...wards', or 'uphill'. For instance, the high energy compound ATP is generated in the cell by coupling its synthesis to the oxidation of sugars , which releases more energy than the syntehsis of ATP requires; then the ATP is broken down in turn by other enzymes coupled to other processes, releasing the energ...

Chromatography

...the retention factor R f , the run length of the compound divided by the run length of the eluent front: The retention of a compound often differs considerably between experiments and laboratories due to variations of the eluent, the...

C4 carbon fixation

...s usually converted to malate , a simple organic compound that gives up its CO 2 to the Calvin cycle after being shipped off to bundle sheath cells surrounding a nearby vein . After losing the CO 2 , it becomes pyruvate , and can be phosphorylated into PEP at the cost of a phosphorus group and on...

Blood

...wes its colour to hemoglobin , a metalloprotein compound containing iron in the form of heme , to which oxygen binds. There exists a popular misconception that deoxygenated blood is blue and that blood only becomes red when it comes into contact with oxygen. Blood is never blue , but veins appear ...

Antibiotic

... to medicine. Although he was unable to purify the compound (the beta-lactam ring in the penicillin molecule...old was of the genus Penicillium , he named this compound penicillin. This USPS stamps notes that during the 1940s, the improvement of antibiotics...

Ames test

...r mutagenic properties of a chemical compound. A compound is said to be mutagenic if it causes a change in the DNA (deoxyriboneucleic acid) of a living cell or organism. The test is named after its inventor, Bruce Ames . General procedure This assay is carried out using strains of bacteria , gen...

Amine

...the nitrogen is part of a carbonyl group, then the compound is considered an amide rather than an amine. ...or pentane-2-amine ) Properties Ions of compound K a (conjugate acid) Aniline C 6 H 5 -NH 2 2.0·10 -5 M Ammonia NH 3 5.6...

Alcohol

...l is a more general term, applied to any organic compound in which a hydroxyl group ( - O H ) is bound ... aryl group is present rather than an alkyl, the compound is generally called a phenol rather than an alcohol. The oxygen in an alcohol has a bond angle of...