Factors that Affect the Activity of Urease Essay example

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Factors that Affect the Activity of Urease

Aim:

To investigate closely the factors that can affect the activity of urease. The effect of concentration and temperature can be studied over a period of time leading to the order and activation enthalpy of the reaction.

Introduction:

UREASE

(NH 2 ) 2 CO + 3H 2 O ----------> 2NH 3 (aq) + CO 2 (g)

Urease is an enzyme found in microorganisms, invertebrates, and higher plants. It catalyses the hydrolysis of urea to ammonia and carbon dioxide. In some bacteria and invertebrates this reaction is the final step in the breakdown of complex nitrogenous compounds before ammonia is excreted.

Method:

Quench
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This combined structure is termed the enzyme-substrate complex. Each type of enzyme will usually act on only one type of substrate molecule. This is because the shape of the active site will only allow one shape of molecule to fit in it. The enzyme is said to be specific for this substrate.

There are two types of enzyme inhibitors: Competitive and Non-Competitive inhibition. If an inhibitor molecule binds only briefly to the active site of the enzyme, there is competition between it and the substrate for the active site. This means it is more likely that the substrate will collide with a filled active site and so this is known as competitive inhibition. It is said to be reversible (not permanent) because it can be reversed by increasing the concentration of the substrate.

Sometimes, the inhibitor can remain permanently bonded with the active site and therefore cause a permanent block to the substrate. No competition occurs as it does not matter how much substrate is present. This is non-competitive irreversible inhibition.

Other factors affecting enzyme activity:

Substrate concentration

As substrate concentration increases, the initial rate of reaction also increases as collisions between enzyme molecules and reactants become more frequent. When the enzymes
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