Embedded Files
Metabolism
Metabolism
Metabolism is a set of chemical reactions that occurs in cells to sustain one’s life. Metabolic reactions can be categorized into catabolic and anabolic reactions.
Catabolic reactions are metabolic reactions that involve break down of larger molecules, energy will be released in the process as ATP.
Anabolic reactions are metabolic reactions that involve build up of molecules, energy is required.
Role of enzymes
Role of enzymes
Enzyme helps speeding up biological reactions, acting as a biological catalyst. For every biological reaction, a certain amount of energy is required to initiate it, called the activation energy. Enzymes speed up those reactions by lowering the activation energy, so that less energy is required to start the reaction.
Actions of enzymes
Actions of enzymes
Catabolic reaction
Catabolic reaction
- Substrate fit into active site on the enzyme
- Enzyme-substrate complex is formed, which lowers the activation energy
- Substrate is converted into products
- Enzyme is released in original form
Anabolic reaction
Anabolic reaction
- Substrates bind with active site on the enzyme
- Enzyme-substrate complex is formed, which lowers the activation energy
- Substrates are converted into product
- Enzymes is released in original form
Properties of enzymes
Properties of enzymes
- Enzymes are biological catalysts - they speed up the reaction of lowering the activation energy
- Enzymes are specific - they only act on substrates that fit into its active site, so each action is unique and specific
- Enzymes are protein
- Enzymes are reusable - they remain unchanged after reactions
Affecting factors of enzyme
Affecting factors of enzyme
Temperature
Temperature
In low temperature, enzymes will become inactive. This is due to the lack of kinetic energy gained from the temperature, thus lowering the rate of collision and the chance of forming an enzyme-substrate complex.
As the temperature comes close to the optimum temperature, the chance of forming the enzyme-substrate complex increases. Therefore, the enzyme will have the maximum action rate right at the optimum temperature.
In high temperatures, enzymes will become denatured, which is a irreversible change. Being denatured, substrates wouldn’t be able to fit into the active site anymore.
pH
pH
Different types of enzymes are best adapted to different environment, including the level of pH. Under the optimum pH, the enzymes will work the best.
pH levels other than the optimum pH are considered unsuitable pH. If the pH is too low or too high to the enzyme, i.e. extreme pH, the enzyme will become denatured. As explained above, the enzyme will thus lose its function.
Inhibitors
Inhibitors
The are certain inhibitors of enzymes, such as cyanide or heavy metals, e.g. mercury. Inhibitors inhibit the enzymes by blocking the active site or change the conformation of the active site.
Report abuse