Enzymes break down complex molecule (for example: carbohydrates, proteins and fats) into simple form.
The diagram shows the interaction between the enzyme and substrate; source: (Marangoni, 2003)
From lab analysis it is seen that the optimum temperature for pepsin is 37◦c, which is the standard human body temperature. If temperature increases or decreases very much, the enzyme substrate reaction rate increases, means it takes longer time to digest protein by the enzyme pepsin (Meridor and Gedanken, 2014). If temperature stayed the same for increased for a while, the enzyme substrate reaction rate decreases, means it takes less time to digest protein by the enzyme pepsin.
Protein hydrolysis is considered as protein breakdown to smaller fragments and also free amino acids. Long polypeptide pepsin can be broken down by hydrolysis. A peptide bond is formed between two molecules, amino group of one molecule and carboxyl group of another molecule. In this reaction R1 and R2 are different hydrocarbon chains. Hydrolysis involves the breakdown of bond within a molecule with the help of water. This type of reaction occurs between a water molecule and an ion and alters solution pH.
Hydrolysis is said to be a dehydration synthesis reaction or condensation reaction and takes place between two amino acids and generates a smaller peptide bond and an amino acid. During hydrolysis an amide changes to ammonia or amine and a carboxylic acid. Carboxylic acid contains hydroxyl group that is derived from water and the amine receives the hydrogen ion and hence gets reduced. The peptide hydrolysis generates amino acids.
Nevertheless, in the absence of pepsin the enzyme substrate reaction conducts much slower. This is effective during high temperature as enzyme pepsin is denatured in high temperature. In the absence of enzyme, reactants accumulate to form an activated complex.
Marangoni, A. (2003). Enzyme kinetics. Hoboken, N.J.: Wiley-Interscience.
Meridor, D. and Gedanken, A. (2014). Enhanced activity of immobilized pepsin nanoparticles coated on solid substrates compared to free pepsin. Enzyme and Microbial Technology, 67, pp.67-76.