In biology, the active site is the region of an enzyme where substrate molecules bind and undergo a chemical reaction. The active site consists of residues that form temporary bonds with the substrate (binding site) and residues that catalyse a reaction of that substrate (catalytic site).
Seattle is rolling out 11 rainbow crosswalks in Capitol Hill this week, adding a colorful bang to the annual Pride celebration. The crosswalks cost the city $66,000, said Seattle Department of Transportation spokesman Rick Sheridan, and are permanent.
The cost of a concrete walkway can vary widely depending on its size and finish. Most U.S. homeowners pay between $6 and $12 per square foot for a new walkway. Prices can go beyond this if significant grading is required or a complex decorative finish is requested. Basic: $6-10 per square foot.