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

Cell 7, 907–913; 2001) have solved a low resolution three dimensional structure of the anaphase ... enzymes to specific substrate proteins. The ubiquitinated proteins are subsequently recognized ...

Enzymes are biological catalysts that speed up chemical reactions in living organisms ... The active site of an enzyme has a unique three-dimensional structure that allows it to bind to a specific ...

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 ...