Effect of substrate concentration on enzyme activity experiment

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Effect of substrate concentration on enzyme activity experiment

Skip the theory and go straight to: How to determine Km and Vmax A simple chemical reaction with a single substrate shows a linear relationship between the rate of formation of product and the concentration of substrate, as shown below: For an enzyme-catalysed reaction, there is usually a hyperbolic relationship between the rate of reaction and the concentration of substrate, as shown below: A At low concentration of substrate, there is a steep increase in the rate of reaction with increasing substrate concentration.

The catalytic site of the enzyme is empty, waiting for substrate to bind, for much of the time, and the rate at which product can be formed is limited by the concentration of substrate which is available.

B As the concentration of substrate increases, the enzyme becomes saturated with substrate. As soon as the catalytic site is empty, more substrate is available to bind and undergo reaction. The rate of formation of product now depends on the activity of the enzyme itself, and adding more substrate will not affect the rate of the reaction to any significant effect.

Effect of substrate concentration on enzyme activity experiment

The rate of reaction when the enzyme is saturated with substrate is the maximum rate of reaction, Vmax. The relationship between rate of reaction and concentration of substrate depends on the affinity of the enzyme for its substrate. This is usually expressed as the Km Michaelis constant of the enzyme, an inverse measure of affinity.

For practical purposes, Km is the concentration of substrate which permits the enzyme to achieve half Vmax. An enzyme with a high Km has a low affinity for its substrate, and requires a greater concentration of substrate to achieve Vmax.

An enzyme with a low Km relative to the physiological concentration of substrate, as shown above, is normally saturated with substrate, and will act at a more or less constant rate, regardless of variations in the concentration of substrate within the physiological range.

Effect of substrate concentration on enzyme activity experiment

An enzyme with a high Km relative to the physiological concentration of substrate, as shown above, is not normally saturated with substrate, and its activity will vary as the concentration of substrate varies, so that the rate of formation of product will depend on the availability of substrate.

If two enzymes, in different pathways, compete for the same substrate, then knowing the values of Km and Vmax for both enzymes permits prediction of the metabolic fate of the substrate and the relative amount that will flow through each pathway under various conditions.

In order to determine the amount of an enzyme present in a sample of tissue, it is obviously essential to ensure that the limiting factor is the activity of the enzyme itself, and not the amount of substrate available.

This means that the concentration of substrate must be high enough to ensure that the enzyme is acting at Vmax. In practice, it is usual to use a concentration of substrate about 10 - fold higher than the Km in order to determine the activity of an enzyme in a sample.

Experiment - the effect of enzyme concentration on amylase activity

If an enzyme is to be used to determine the concentration of substrate in a sample e. The relationship is defined by the Michaelis-Menten equation: A number of ways of re-arranging the Michaelis-Menten equation have been devised to obtain linear relationships which permit more precise fitting to the experimental points, and estimation of the values of Km and Vmax.

There are advantages and disadvantages associated with all three main methods of linearising the data. The Lineweaver-Burk double reciprocal plot rearranges the Michaelis-Menten equation as: These are the points at which the precision of determining the rate of reaction is lowest, because the smallest amount of product has been formed.

The Eadie-Hofstee plot rearranges the Michaelis-Menten equation as: However, it has the disadvantage that v, which is a dependent variable, is used on both axes, and hence errors in measuring the rate of reaction are multiplied, resulting in lower precision of the estimates of Km and Vmax The Hanes plot rearranges the Michaelis-Menten equation as:• Design of experiments to test the effect of temperature, pH and substrate concentration on the activity of enzymes When designing an experiment to test the effect of factors affecting enzyme activity, the three key decisions to be made are.

This is an experiment to examine how the concentration of the substrate hydrogen peroxide affects the rate of reaction of the enzyme catalase. Introduction This is an A-level biology project. In order for an enzyme to perform its given job, it needs what is known as a substrate to bind to the active site of the enzyme so that the enzyme can speed up the reaction of the substrate.

In this given experiment, it was to be tested what impact the concentration level of substrate will have on the reaction rate. Effect Of Substrate Concentration On The Activity Of Catalase Effect Of Substrate Concentration On The Activity Of Catalase AIM This is an experiment to examine how the concentration of the substrate hydrogen peroxide affects the rate of reaction of the enzyme catalase.

An enzyme makes a reaction proceed faster, but is not consumed in the reaction.

An enzyme with a high Km relative to the physiological concentration of substrate, as shown above, is not normally saturated with substrate, and its activity will vary as the concentration of substrate varies, so that the rate of formation of product will depend on the availability of substrate. Apr 30,  · Investigate the effect of substrate concentration on the rate of activity of the enzyme catalase. Hypothesis I believe that as the concentration of the hydrogen peroxide (substrate) decreases, the rate of reaction will decrease as arteensevilla.coms: 5. Introduction. Amylase is an enzyme present in saliva and pancreatic juice. It catalyses the hydrolysis of amylose and amylopectin (both starch components) to a mixture of products including maltose and dextrin.. Aim. To investigate the effect of amylase concentration on its activity. The relative activity is determined by noting the time taken for the starch substrate to break down.

This means that the more substrate there is, the more enzyme activity can be observed. However, the effect of substrate on enzyme activity is not simply to increase it.

Substrate concentration has many different effects. - Investigating the Effect of Substrate Concentration on Catalase Reaction Planning -Aim: The aim of the experiment is to examine how the concentration of the substrate (Hydrogen Peroxide, H2O2) affects the rate of reaction of the enzyme (Catalase).

Effect of Substrate Concentration on the Rate of Activity of Catalase | Owlcation