enzyme tertiary structure

• enzymes are very specific and usually only catalyse one reaction
• only one complementary substrate will fit into an enzyme's active site e.g. maltase only breaks down maltose
• the active site's shape is determined by the enzyme's tertiary structure (which is determined by the enzyme's primary structure)
• each enzyme has a different tertiary structure and therefore a different shaped active site
• if the tertiary structure of the enzyme is altered in any way the shape of the active site will change, which means the substrate won't fit into the active site, an enzyme-substrate complex won't be formed and the reaction won't be catalysed
• the tertiary structure can be altered by changes in pH or temperature
• the primary structure (amino acid sequence) of a protein is determined by a gene. if a mutation occurs in that gene it could change the tertiary structure of enzyme produced