Вопрос
3. Trypsin catalyzes the degradatation of proteins: -met-ser-tyr-lys-glu-ala-. __ -met-ser-tyr-lys + glu-ala- __ Optimum of enzyme action -pH=7,8,t^circ =37^circ This enzyme is secreted by pancreas as zymogen - trypsinogen. 1) Specify the class of the enzyme. Name and explain the mechanism of this enzyme activation.. 2) Draw the plot and explain the effect of substrate concentration on the reaction velocity. Give the definition of Km. 3) Show effect of pH=3 on enzyme activity and explain it.
Решения
3.3
(169 Голоса)
Эдуард
мастер · Репетитор 5 лет
Ответ
1) Trypsin is a proteolytic enzyme, which belongs to the class of enzymes called peptidases. Peptidases are enzymes that catalyze the hydrolysis of peptide bonds in proteins, breaking them down into smaller peptides or individual amino acids.The mechanism of trypsin activation involves the conversion of its inactive precursor, trypsinogen, into its active form, trypsin. This activation occurs through the cleavage of specific peptide bonds in the trypsinogen molecule by another enzyme called enterokinase, which is secreted by the cells lining the small intestine. The cleavage of these peptide bonds results in the formation of the active tr-Menten plot. In this plot, the reaction velocity is plotted on the y-axis, and the substrate concentration is plotted on the x-axis.As the substrate concentration increases, the reaction velocity also increases, following a hyperbolic curve. This is because as the substrate concentration increases, more substrate molecules are available for the enzyme to bind to, leading to an increase in the reaction velocity. However, once the substrate concentration reaches a certain level, the reaction velocity reaches a that the enzyme has become saturated with substrate, and increasing the substrate concentration not increase the reaction velocity.The Km value, which is the substrate concentration at which the reaction velocity is half of the maximum velocity, is a measure of the affinity of the enzyme for its substrate. A lower Km value indicates a higher affinity of the enzyme for the substrate, meaning that the enzyme can achieve half of its maximum velocity at a lower substrate concentration.3) The effect of pH on enzyme activity can be represented by a pH-activity plot. In this plot, the enzyme activity is plotted on the y-axis, and the pH is plotted on the x-axis.As the pH deviates from the optimum pH of 7.8, the enzyme activity decreases. At a pH of 3, the enzyme activity is significantly reduced. This is because the low pH causes the enzyme's active site to become protonated, leading to a decrease in the enzyme's ability to bind to its substrate. As a result, the reaction velocity decreases, and the enzyme's activity is reduced.