Metabolic Pathways
- Metabolic pathways involve a series of small steps, each step involves a chemical change
- The enzyme-catalysed reactions that make up metabolic pathways usually consist of chains or cycles:
- Chain reactions are a linear sequence with a distinct beginning and end
- Glycolysis, part of respiration, is an example of a reaction chain metabolic pathway
- Cycles involve the end product starting the next cycle, these are less common than chain reactions
- The Calvin cycle, part of photosynthesis, is an example of a cyclic metabolic pathway
- Chain reactions are a linear sequence with a distinct beginning and end
A chain metabolic pathway has a distinct start and finish, whereas in a cycle the end product feeds back into the starting reactant
- Chemicals involved in metabolic pathways are called metabolites or intermediates
- Some form new molecules within cells
- Others breakdown molecules and involve an energy transfer