enzymes in cells

• chemical reactions in cells are controlled by enzymes
• catalysts speed up reactions
• during reactions, catalysts are not used up
• enzymes are biological catalysts
• enzymes are proteins
• enzymes are proteins that speed up reactions
• one particular enzyme can catalyse only one reaction
• each switched on gene produces a particular protein
• many of the proteins produced by genes are enzymes
• the chemical reactions that happen in cells are all said to be metabolic
• all enzymes are involved in all metabolic reactions
• An enzyme will break large molecules into smaller ones or build large molecules from small ones