Enzymes

• Activation energy is the amount of energy needed to begin a reaction
• Intra Cellular is anything contained in the plasma membrane
• Enzymes are globular proteins with specifically shaped active sites which bind to substrates with weak non covalent bonding - hydrogen and ionic
• Enzymes can lower activation energy by changing shape to put pressure on bonds or changing the local pH or temperature
• By keeping the activation energy low locally, the organism maintains a safe internal temperature
• Enzymes undergo a conformational change of shape where the active site will change shape to become more complimentary to the substrate, the substrate will bind and pressure will break the bonds in the enzyme substrate complex, this is called the induced fit model
• Enzymes and substrates rate of reaction increases when there is a higher temperature so more kinetic energy, when there is more enzyme available, when there is more substrate available, this increases the rate of collision
• Enzymes have an active site which is complimentary to the substrate by specific shape
• A competitive inhibitor will be a similar shape to the substrate and so will fill the active site, saturating available enzymes thus reducing the rate of reaction
• A non competitive inhibitor will bind to the allosteric site, causing a change in shape of the active site where it will become more or less complimentary to the substrate, changing the rate of reaction
• Enzyme inhibition can cause a negative feedback loop to form where the final product of a chain of enzyme reactions inhibits the first enzyme reaction to maintain a balance of product
• Metabolism is the sum of all reactions within a cell