active site

(redirected from active sites)
Also found in: Dictionary, Thesaurus, Encyclopedia.
Related to active sites: Lock and Key Model, induced fit model

ac·tive site

that portion of an enzyme molecule at which the actual reaction proceeds; considered to consist of one or more residues or atoms in a spatial arrangement that permits interaction with the substrate to effect its reaction.

active site

The part of an enzyme at which catalysis of the substrate occurs.

active site

the place on the surface of an enzyme where its catalytic action occurs.

Active Site

The site in an enzyme where a substrate binds and an enzymatic reaction—e.g., ligation, oxidoreduction, etc.—occurs. The structure of the amino acid residues within the active site enhances substrate binding, substrate activation, and formation of a transition state.

ac·tive site

(ak'tiv sīt)
That portion of an enzyme molecule at which the actual reaction proceeds; one or more residues or atoms in a spatial arrangement that permits interaction with the substrate.

active site

1. The region of an ENZYME to which the substance being affected binds so as to undergo a catalyzed reaction.
2. The localized part of a protein to which a substrate binds.
Active siteclick for a larger image
Fig. 11 Active site . Lock-and-key mechanism of enzyme activity.

active site

an area of ENZYME surface which has a shape complementary to a particular SUBSTRATE, enabling the enzyme and substrate to become temporarily bonded to form an enzyme-substrate complex. Such a lock-and-key mechanism explains the great specificity of enzymes for substrates and also why changes in enzyme three-dimensional shape (by pH, temperature) cause alterations to enzyme activity.


not passive.

active principle
the drugs or chemicals in a pharmaceutical preparation that exert an effect pharmacologically; as distinct from the inert fillers, wetting agents and other excipients also often included.
active site
that region of a protein, usually an enzyme, that binds to another molecule such as the substrate of the enzyme.
active transport
the movement of ions or molecules assisted by a carrier protein across the cell membranes and epithelial layers, usually against a concentration gradient, resulting directly from the expenditure of metabolic energy. For example, under normal circumstances more potassium ions are present within the cell and more sodium ions extracellularly. The process of maintaining these normal differences in electrolytic composition between the intracellular fluids is active transport. The process differs from simple diffusion or osmosis in that it requires the expenditure of metabolic energy.

Patient discussion about active site

Q. Are there any nice activities for adults with autism? I've been helping a very nice man of 45 of years old and I'm looking for some new things I can do with him in our time together. any ideas?

A. Autistic people react wonderfully with animals. for instance- i saw a group of severe Autistic teenagers going to swim with dolphins. the effect was amazing! taking him to the zoo, or even to the park to feed ducks, pet dogs, whatever.. could have a great effect on him.
hope i helped!
tell me how it went.

Q. what is a passive smoking? and is it dangerous as an active?

A. Passive smoking is the exposure to cigarettes smoke emitted from cigarettes smoke by other person. It's dangerous and may increase the risk to several diseases similar to active smoking (one's exposure to smoke emitted from the cigarettes he or she is smoking) although the risk is of lower magnitude. Example for passive smoking is children of smokers etc.

You may read more here:

Q. i swim a lot ! what are the advantages of swimming over other sport activities? on what part of the body does it work the most ?

A. its a good workout but your not really going to burn as much calories as a regular work out.

More discussions about active site
References in periodicals archive ?
Total polymer volume is the sum of that formed at the active sites that were exposed during the first step (polymer produced during both the first and the second fragmentation steps) and that formed at the active sites exposed after the first rupture:
This replication effect re-exposes active sites, the access to which was previously blocked by polymer.
Contract notice: Annual road management for the active site residenzstraE-e.
The Kent-based builder, which trades from 85 active sites, added that sales prices have been modestly ahead of its hopes.
Chirality in biological nanospaces; reactions in active sites.
However, the molecular weight distributions (MWDs) of the resulting polymers are not controlled well because of the presence of multiple active sites and the heterogeneity of the catalyst system [1-10].
In the period of the trading update, Barratt said it operated from an average of 349 active sites.
The firm had 362 active sites at the start of November - down 19% on a year ago.
ClinPhone Site Manager is a web-based clinical trial solution that enables Clinical Operations personnel to effectively manage all processes related to the selection and activation of clinical trial sites, as well as facilitate ongoing communication with active sites.
Students learn about certain properties of enzymes such as: active sites, interactions with substrates, specificity for substrates, and the upper limits of temperature imposed upon their catalytic activities.
two active sites in Balatonszarszo (opened in May 2006) and Keszthely (opened
Only 35 years ago, scientists didn't know that geologically active sites existed underwater.

Full browser ?