Active Site

In biology and biochemistry, the active site of an enzyme is a region to which another molecule or molecules can bind. This molecule is called the substrate. The shape of the active site allows this particular substrate to fit correctly, and to be held in place by temporary bonds. The active site in many enzymes can be inhibited or suppressed by the presence of another molecule. There are two ways in which this can occur. In competitive inhibition, the active site itself is blocked when a molecule similar in shape to the substrate bonds to the active site and cannot be processed by the enzyme. In noncompetitive inhibition, a molecule bonds to the enzyme at another site, the allosteric site, and this bond causes the enzyme to transform such that the active site is rendered useless. Often certain metabolic pathways are designed such that after several stages negative feedback will cause the inputs of the system to become reduced. There are two theories of how enzymes work: the lock and key mechanism and an alternative theory whereby the active site binds and encloses onto the substrate molecule. Often enzymes bond to their substrate by Van der Waals forces or hydrogen bonds between the R' groups in the amino acid monomers.

Commercial Usage: Active Site

Domain	Title
Books	Experimental Studies on Thrombosis and Thrombolysis: With Special Reference to Importance of Lys-Plasminogen, Active Site Thrombin Inhibitors and sta (reference) (more book examples)
Source: compiled by the editor from various references; see credits.

Non-Fiction Usage: Active Site

Subject	Topic	Quote
Health		Building on this finding, researchers at Harvard Medical School showed that changing the structure of presenilin 1 at its active site dramatically altered a cell's ability to make the gamma secretase cut in APP (Kimberly et al., 2000). This correlation was also shown to be true for presenilin 2, the protein product of a gene very similar to presenilin 1 that, when mutated, can cause familial early-onset AD. These results strongly suggested, but did not prove, that gamma secretase and the presenilins were one and the same. Further evidence supporting this possibility came from a pharmaceutical company-supported team, closely followed by the Harvard Medical School group. (references)
Source: compiled by the editor from ICON Group International, Inc.; see credits.

Anagrams: Active Site

Scrabble® Enable2K-Verified Anagrams
	Words within the letters "a-c-e-e-i-i-s-t-t-v"
	-2 letters: activist, cavities, estivate, vesicate, vitiates.
	-3 letters: actives, casette, catties, cavetti, statice, stative, vesicae, vitiate.
	-4 letters: active, attics, cattie, cavies, cities, civets, civies, estate, evicts, evites, iciest, stacte, static, testae, vesica, viatic, vittae.
	-5 letters: attic, caste, cates, caves, cavie, cease, cesta, cesti, cetes, cites, civet, civie, eaves, evict, evite, ivies, saice, scatt, setae, sieve, state, stave, taces, tacet, tacit, tacts, taste, tates, tease, teats, tecta, testa, titis, vatic, vesta, vices, visit, vista, vitae, vitta.
	Words containing the letters "a-c-e-e-i-i-s-t-t-v"
	+1 letter: recitatives.
	+2 letters: creativities, reactivities.
	+3 letters: affectivities, gesticulative, resuscitative, verticalities.
	+4 letters: overactivities, refractivities.
	+5 letters: antispeculative, hyperactivities, noncreativities, retroactivities, superactivities, underactivities.
Source: compiled by the editor from various references; see credits. SCRABBLE® is a registered trademark. All intellectual property rights in and to the game are owned in the U.S.A and Canada by Hasbro Inc., and throughout the rest of the world by J.W. Spear & Sons Limited of Maidenhead, Berkshire, England, a subsidiary of Mattel Inc. Mattel and Spear are not affiliated with Hasbro.