Enzymes1 essays

Enzymes1 essays An enzyme is a catalyst, which is a chemical agent that changes the rate of a reaction without being consumed by the reaction. The reactant that an enzyme acts on is called its substrate. While the enzyme is bound to the substrate, the catalytic action converts the substrate to the product. Because of its shape, each enzyme catalyzes a specific reaction (molecular recognition). Only a certain region of the enzyme molecule actually binds to the substrate. This area is called the active site and is usually a groove on the surface of the enzyme. The shape of the active site and the shape of the substrate fits accordantly. When the substrate enters the active site, it induces the enzyme -in a process called induced fit- to change its shape to fit tightly around the substrate. The induced fit is very important during the catalytic cycle when the substrate enters the active site to form an enzyme-substrate complex. The enzymes emerge from the reaction, however, in their original f orm and are ready to function over and over again. When a reaction rearranges the atoms of molecules, the bonds in the reactants must be broken and the new bonds in the products must be formed. This requires energy. The energy required to break the bonds in the reactant molecules is known as the activation energy. The bonds only break when the molecule has absorbed enough energy (usually in the form of heat) to become unstable. Heat speeds up a reaction, but the high temperature kills cells; therefore, organisms must instead use a catalyst. Enzymes (mostly proteins) are biological catalysts. Enzymes speed up reactions by lowering the barrier of activation energy, so that the transition state is within reach at regular temperatures. A transition state occurs when reactants are in an unstable condition and are ready for the reaction to take place. An enzyme cannot changes the free energy of the reaction or the spontantinuity of the reaction. It can ...

Ortiz Surname Meaning and Origin

Ortiz Surname Meaning and Origin The name Ortiz is a patronymic surname meaning son or Orton or Orta, with its origin in Spanish. Ortiz is the 94th most popular surname in the United States and the 16th most common Hispanic surname. Alternate Surname Spellings: Ortize, Ortez, Ortaz, Ortes, Ortis Famous People with the Surname ORTIZ: David Ortiz - Major League Baseball Player.Victor Ortiz - professional American boxer.Russ Ortiz - Major League Baseball Pitcher.Tito Ortiz - MMA (Mixed Martial Arts) Fighter. Genealogy Resources for the Surname Ortiz Genealogy.com allows you to search the popular genealogy forum for the Ortiz surname to find others who might be researching your ancestors, or post your own Ortiz query. With FamilySearch.org you can find records, queries, and lineage-linked family trees posted for the Ortiz surname and its variations. RootsWeb hosts several free mailing lists for researchers of the Ortiz surname. Cousin Connect  allows you to read or post genealogy queries for the surname Ortiz, and sign up for free notification when new Ortiz queries are added. DistantCousin.com provides access to free databases and genealogy links for the last name Ortiz. References Cottle, Basil. Penguin Dictionary of Surnames. Baltimore, MD: Penguin Books, 1967. Menk, Lars. A Dictionary of German Jewish Surnames. Avotaynu, 2005. Beider, Alexander. A Dictionary of Jewish Surnames from Galicia. Avotaynu, 2004. Hanks, Patrick and Flavia Hodges. A Dictionary of Surnames. Oxford University Press, 1989. Hanks, Patrick. Dictionary of American Family Names. Oxford University Press, 2003. Smith, Elsdon C. American Surnames. Genealogical Publishing Company, 1997.