The following links offer some useful revision on Cell Structure to support your learning:
Metabolic Pathways Wordwall Game
At Higher, you will need to know the following:
- Metabolism encompasses the integrated and controlled pathways of enzyme catalysed reactions within a cell.
- Anabolic pathways require energy and involve biosynthetic processes.
- Catabolic pathways release energy and involve the breakdown of molecules.
- These pathways can have reversible and irreversible steps and alternative routes.
- Metabolic pathways may exist that can bypass steps in a pathway
- Control of metabolic pathways — presence or absence of particular enzymes and the regulation of the rate of reaction of key enzymes within the pathway. Regulation can be controlled by intra and extracellular signal molecules.
- Metabolic pathways are controlled by the presence or absence of particular enzymes in the metabolic pathway and through the regulation of the rate of reaction of key enzymes within the pathway.
- Genes for some enzymes are continuously expressed. These enzymes are always present in the cell and their control involves regulation of their rate of reaction.
- Most metabolic reactions are reversible and the presence of a substrate or the removal of a product will drive a sequence of reactions in a particular direction.
- Induced fit and the role of the active site of enzymes including shape and substrate affinity. Activation energy.
- The role of the active site in orientating reactants, lowering the activation energy of the transition state and the release of products with low affinity for the active site.
- The effects of substrate and end product concentration on the direction and rate of enzyme reactions.
- Enzymes often act in groups or as multi-enzyme complexes.
- Control of metabolic pathways through competitive (binds to active site), noncompetitive (changes shape of active site) and feedback inhibition (end product binds to an enzyme that catalyses a reaction early in the pathway)
- Competitive inhibition can be reversed by increasing substrate concentration.
