Aim: To investigate:
• Effect of change in (i) temperature and (ii) amount of lipase on the digestion of fat in milk using electronic pH indicator.
Enzymes are biological molecules that quicken the rate of reaction within cells. Each enzyme has a specific function. Enzymes help in breaking down the food eaten by humans in order to make energy. Every substrate has its own enzyme. Enzymes have cracks on their surface, known as active sites. Molecules (substrates) with the same shape as the active site can fit there. This can be illustrated by the following ‘Lock and key’ diagram :
Lipase is an example of enzymes. It breaks down fats into fatty acids and glycerol. The cells in or stomach produces gastric lipase which digests…show more content… Lipids are biological molecules that are insoluble in water, but are soluble in non-polar solvents, meaning that they are non-polar molecules. Lipids have various functions. Lipids contain a high amount of energy and sometimes even contain essential vitamins and nutrients. Lipids also help in insulating the body and facilitating the digestive process.
The most typical types of lipids are triglycerides. A triglyceride is a lipid molecule made up of one unit of glycerol and three fatty acids. This can be seen in the image below :
Triglycerides are the results of condensation reactions that involve the –OH groups of glycerol and –COOH group of fatty acids. Even though condensation reactions produce ester bonds, lipase uses three molecules of water to break three ester bonds and make one molecule of glycerol and three molecules of fatty acid in order to oxidize triglycerides.
The diagram above shows the process of oxidation of lipids. Oxidation of lipids releases twice as much energy as carbohydrates. Hence, lipids are more apt for generating ATP in cell…show more content… Hence, the pH will fall quicker. This will be because as the concentration of an enzyme increases, there are more active sites allowing more substrates to bind with them and increasing the rate of hydrolysis. Ultimately, there will be limited substrates to bind with the active sites on the enzymes so the rate of reaction is low.
With an increasing rate of reaction, rate of changing pH increases. As triglycerides release fatty acids faster, the pH decreases at rapid rates. When all the active sites of the enzymes work at full capacity and no more hydrolysis can take place, the pH will still fall as hydrogen ions are still getting released.
Also, I have predicted that hydrolysis of the lipase will be fastest at 37°C (body temperature). As temperature increases, collisions between the molecules increase. This is because the kinetic energy and velocity increase as well. Faster velocity means there will be less time between collisions of the molecules. Hence, the rate of reaction increases. However, as enzymes are proteins, they will be broken down at higher temperatures which will slow down the rate of reaction due to less collusion. Also, this suggests that there won’t be any hydrolysis at 0°C due to no collusions. So 37°C is the optimum