the free energy of the reactants is greater than that of the products. induced-fit model. A model of enzyme-catalyzed reactions in which the enzyme changes shape when substrates bind to the active site; this change in shape is called an induced fit. lock-and-key model A model of enzyme-catalyzed reactions in which the enzyme is a rigid lock and the substrates are the keys that fit into the lock and then react.
System administrator. For the privileged user account, see Superuser. A system administrator, or sysadmin, is a person who is responsible for the upkeep, configuration, and reliable operation of computer systems; especially multi-user computers, such as servers.
Security Accounts Manager (SAM) The Security Accounts Manager (SAM) is a database in the Windows operating system (OS) that contains user names and passwords. SAM is part of the registry and can be found on the hard disk. Download this free guide.