An increase in temperature leads to a higher collision rate due to increased kinetic energy. The optimal temperature for collision rate is approximately 37.5 degrees Celsius ( Rsb.org, 2022). Enzymes are able to function from 5 degrees Celsius to 60 degrees Celsius (FSANZ, 2022).

Possible testing equipment: Colourimeter

Possible designs (Independent and Dependant variables)
IV: water temperature
DV: reaction rate

CV:

• amount of enzyme
• amount of substance (oil etc.)
• type of stain substance (fat - oil etc.)
• time each solution is left for
  

Enzymes lower the activation energy required for a reaction by binding to substrates (Khan Academy, 2022). Therefore, increasing enzyme concentration will speed up enzyme function, so long as there is substrate for the enzymes to bind to (Khan Academy, 2022). In the context of laundry detergents, a higher concentration of enzymes in the washing solution will increase the efficiency with which it can remove stains (substrate) from clothing.

Possible experiment: Enzyme function could be measured by creating 4 different dilutions of water and the lipase (100%, 80%, 40%, 0% (control). 4 test tubes of oil are also prepared. Each enzyme solution is added to its respective test tube of oil. Leave for 30 minutes (Cleaning Institute, 2022). Take a small sample of the 100% dilution and observe its effect on the oil using a colourimeter. Repeat for each dilution. IV: Enzyme concentration, DV: Enzyme efficiency in breaking down the oil

A Colourimeter helps determine the concentration of substances by comparing the amount of light passing through a solution to the amount that can pass through a pure solvent (T Bullet, 1999).

Favourable enzyme functionality can be measured by comparing the light passing through each dilution to light passing through a pure solvent, in terms of similarity. This will indicate how well the lipase has broken down the oil in each dilution