Question

6. (5pts) Draw relative plots for reaction rate as a function of substrate concentration for a) a reaction with tight enzyme:substrate binding, and b) a reaction with weak enzyme:substrate binding. Label the Vmax and Kn for each plot, and explain what the Vmax and Km tell you. Which Km is larger?

Answer 1

Ans :

During the enzyme and substrate are combined and the enzyme is catalzyed the reaction , it will get at particular substrate concentration . When product concentration is linearly increase. The amount of product produced at starting of reaction per unit is known as initial velocity (V_{​​​​​​0}​​​) of the concentration.

Now , the plots for reaction rate

a) a reaction with tight enzyme substrate binding site.

In this plotting reaction are shown below, which are determined information of enzyme kinetics. Here substrate having different concentration when we will add enzyme ( Same concentration).

By the V_{​​​​​​0} value of all concentration will determine on plotted (X, Y) pair. While in presence of enzyme. it will tightly bind with substrate and form enzyme substance concentration . The V_{​​​​​​0} value will rapidly increase at low substrate concentration and at high substrate concentration it will flat.

This plotted examine the enzyme is saturated, it mean as that all available enzymes are tighted up with substrate. After that substrate will also wait for another enzyme to trigger reaction. This maximum rate of reaction will determine by Maximum velocity ( V_{​​​​​​max} ). Which plotted on Y .

The half way to Vmax of substrate concentration of reaction rate is known as K_{​​​​​​m.} It is used for measure of reaction rate increase with substrate concentration and measure affinity towards enzyme.

Lower K_{​​​​​​m} = higher affinity for substrate

Higher K_{​​​​​​m} = lower affinity for substrate

X Rate of reaction km Substrate concentration

V_{​​​​​​Max} dependes on enzyme concentration K_{​​​​​​m} which is same for particular enzyme reaction. K_{​​​​​m} can be changed by inhibitors.

b) a reaction with weak enzyme substrate binding.

Some inhibitors are play role in enzyme substrate binding activity. Such as compititive inhibitor and non compititive inhibitor.

In case of competitive inhibitors trigger reaction by binding to a enzyme at the active site and get the substrate from binding.

When compititive inhibitor bind to the enzyme it will acts by decreasing or weaker the number of enzyme molecules to bind with substrate.

In the graphic reaction V_{​​​​​​max} reach normal, when substrate added and the enzymes are inhibits by inhibitors so the effective concentration of enzyme V_{​​​​​​max} is reduced and K_{​​​​​m} is not changed.

Vmux Maximum state of reaction Normar- enzyme Competitive of Reaction Inhibitor Same Wroxx different km Rate 1 Substrate concening hoy km

The unchanged K_{​​​​​​m} get that inhibitors doesn't affect enzyme binding to substrate at lower concentration of enzyme.

When reaction with weak enzyme substrate binding activity it will get higher K_{​​​​​​m.}