Substrates in biological cells must be continuously transported ... which together form a complex three-dimensional structure ...

Proteins can be big or small, mostly hydrophilic or mostly hydrophobic, exist alone or as part of a multi-unit structure ... are highly specific to their substrates. They bind these substrates ...

Enzymes are biological catalysts that speed up chemical ... The active site of an enzyme has a unique three-dimensional structure that allows it to bind to a specific substrate, much like a lock and ...

It is a perfect match to the shape of the substrate molecule ... and therefore the enzyme has a unique shape. This structure is held together by weak forces between the amino acid molecules ...