The rate of lipase is to measure the difference in time in the breakdown of milk into glycerol and fatty acids. Temperature affects the rate of lipase, so five different temperatures are introduced. This can be seen from the independent variables below which will influenced the change in rate of lipase activity.
Independent variables: Temperature 0oC, 20oC, 30oC, 40oC, 50oC. (controlled)
Dependent variables: Percentage change in rate of lipase activity over a given period of time
Milk volume: Milk had to be maintained at equal volumes so as to give uniform results. Milk volume was controlled by adding 5cm3 in every test tube. Milk needed to be within a controlled temperature at 6oC.
Room temperature: To ensure same starting temperature throughout the experiment. Room temperature was controlled at around 25oC.
Volume of Lipase: To ensure an equal amount of lipase solution was used in each test.Lipase was controlled by maintaining a volume of 1cm3 lipase solution
pH level: Lipase is affected by the changes in pH levels. PH has an optimum level therefore other levels other than its optimum will affect lipase in breaking down milk.
Risk assessments for this experiment
Lipase solution: It may be flushed into the eyes. Wear gloves and in case of contact with skin or eyes wash with water.Lipase in milk are found in the native milk, airborne bacterial contamination, bacteria that are added intentionally for fermentation or in somatic cells present in milk. (milkfacts.info)
Glass apparatus: It has a risk of breaking and causing injury. Handle with care and avoid placing the at the edges of working benches.
Phenolphthalein: It is flammable, therefore not to swallow, get contact with the eyes or touch by hands. Wear googles and gloves. If contact, wash hands carefully.
Sodium carbonate solution: It is toxic which has a risk in inhalation, skin, eyes and ingestion. Wear googles and gloves.
Temperature impacted the action performed by lipase in this manner as the increase in temperature at approximately 40 degrees Celsius will end up increasing the level of reaction. This is enabled by an increase in the rate of collision among the substrate molecules and enzyme. This is similar to the case of any specific chemical reaction. The maximum level of reaction for the enzyme is across the optimum temperature. The level of reaction contributed in reducing with an increase in temperature to the limit that the reaction ends up stopping. This is because of higher level of temperatures at more than 40 degrees Celsius, the structure of protein is denatured for the enzyme through heat. The molecule ends up losing the shape and there is deactivation of the enzyme. There is a crucial necessity for breaking down fat during digestion for simplifying its absorption by the gut membranes and sufficient solubility for its transportation within the blood. As the overall scenario changes, changing the concentration level of enzyme leads to altering the speed at which the reaction takes place. The enzymes ended up reducing the time or increasing the overall speed. There was a crucial requirement of using similar volumes at all of the temperatures. Digested fat ends up producing glycerol and fatty acids for the neutralization of sodium carbonate or alkali. Thus, this lowers the level of pH and change the colour of phenolphthalein (Takci, 150). This includes the utilization of data logger or pH prove, or a different indicator.