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.
A network administrator, sometimes called a systems administrator, is responsible for keeping an organizationâs computer network up to date and running smoothly. Any company or organization that uses multiple computers or software platforms needs a network admin to coordinate the different systems.