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What are the optimal operating conditions for enzymes? - Coggle Diagram

- - - - Low temperature (0°C-30°C) - while certain enzymes, such as psychrophilic enzymes, operate best within the 0°C-15°C temperature range (DNA ligase also is at an optimal rate of reaction at around 25°C), low temperatures are generally not favourable environments for human-specific biological enzymes. The two mentioned enzymes are exceptions to the general idea that enzyme activity is slower at lower temperatures, given that the former enzyme actually benefits off a slightly denatured form -> the active site is more flexible and better able to accommodate its substrate.
      - Medium temperature (30°C-45°C) - most enzymes work best within this range (37°C-40°C) as this range matches that of the human body: their main 'biologically relevant' environment. It can be considered that over time, enzymes adapted to suit this range so that metabolic reactions would still be able to occur at an efficient level.
      - High temperature (45°C+) - like the low temperature, this temperature range is not optimal for most enzymes, with some exceptions - thermophilic/hyperthermophilic enzymes. An example of a thermophilic enzyme is Taq polymerase, a common enzyme used in PCR (polymerase chain reaction) amplification; its optimum temperature range is between 70°C-75°C. Again, these enzymes are exceptions to the general idea that enzyme activity sharply declines at higher temperatures thanks to the denaturing/deforming of enzyme shapes.
      - Since temperature is the independent variable, the temperatures 15°C, 25°C, 35°C and 45°C have been selected to display the full impact that temperatures in non-optimal environments have on enzyme activity.
  - - - Acidic pH (1-6) - optimum enzyme ranges depend on the enzyme's main role and location inside the human body. For example, pepsin is a protein-digesting enzyme located in the acidic environment of the stomach and functions best at a pH of 2.5. Pepsin's acidic side chains (as a protein, it is composed of amino acids) are protonated (positively charged), and its substrates (e.g hemoglobin) are negatively charged at this pH level, which enables the enzyme to attract to its substrate and function with ease.
      - Neutral pH (7) - as with temperature, most enzymes perform best at this neutral level with exceptions given that the protein and its acidic/basic side chains remain stable, and the enzyme is not denatured. Additionally, the overall pH of the human body is also relatively neutral (7.35-7.45).
        
        A neutral pH (7) has been selected for this experiment as a controlled variable purely because lipase's side chains - which are sensitive to changes in pH - are uncharged and thus 'neutral' at pH 7, allowing them to work at an optimum efficiency. The use of any other pH values would open the risk of the enzyme denaturing and being unable to operate effectively.
      - Basic pH (8-14) - trypsin is an example of an enzyme that thrives in a more alkaline (pH of 8-10) environment. Its composition of more 'basic' amino acids allows it to be able to maintain structure and catalyse reactions even as its surroundings become more basic.