Please can someone explain to me what this question is asking for..

 

Explain the principles of estimating the rate of an enzyme catalysed reaction and the importance of measuring the initial rate of reaction..?

 

Thanks

enzyme can risie up the rate of chemical reaction (including catabolism and anabolism) for producting more enegry or absorbing more enegy)

 

enzyme lower the activation enegry of the chemical reaction

 

the answer is referred from Hong Kong public examination paper

The initial rate is the beginning of the of the reaction under enzymes normal conditions, so by knowing the initial rate you will be able to accurately compare each enzyme catalysed reaction when changing different variables, such as temperature or adding more substrate which will either increase or decrease the rate of reaction. The increase and decrease will be determined by comparing to the initial rate reaction.

 

Hope this helps.

An enzyme is a biological catalyst that speeds up a reaction without actually taking part in it. Now there are many factors that affect the rate of any reaction. These are:

1. Temperature

2. Surface Area

3. Pressure

4. Number of moles

And a few more...

The importance of knowing the initial rate of reaction is so that we can be able to accurately compare the results with the starting conditions that affect the reaction.

Can you define "initial rate" for us?

I'd say that this question is asking what affects the rate in which an enzyme acts as a catalyst to a chemical reaction.

 

The rate of reaction of enzymes is dependent on the quantity of enzymes in a given system (more enzymes = more substrates being broken down). It is also dependent on the temperature of the system. I'll take a snippet from one of my past biology assignments to explain this:

 

"Collision theory states that reactant particles must collide in order for a reaction to occur. The more particle collisions that occur, the greater the reaction rate will be (GCSE Bitesize BBC, 2014). As the temperature of a given system rises, the kinetic energy of the particles also rises. When particles possess a higher amount of kinetic energy, there is a greater likelihood that they will collide with one another (GCSE Bitesize BBC, 2014). In order for enzymes to convert substrates to products, the enzymes must firstly collide, and then bind to the substrates at the active site. Therefore, increasing the temperature of the system will also increase the amount of collisions that occur between the enzymes and the substrates. This will, as a result, increase the reaction rate of the system (Brooklyn College, n.d.)."

 

The rate of reaction will also decrease after a given temperature, as the enzymes will begin to denature (deform), preventing the substrates from binding to the active site.

 

Measuring the initial reaction rate is important if you wish to record the increase (and eventual) decrease in reaction rate due to the enzymes catalyzing the chemical reaction.

 

I hope this answer was comprehensive enough.

The initial rate means the rate measured before much (ca. 5%) substrate has been consumed or product produced. If this condition is not fulfilled, the rate measurements are suspect.

Firstly please all not the dates on the original posts in this thread.

 

 

Dr Patterson, please also note that the kinetics of enzyme catalysed reactions is a specialist university subject, far beyond GCSE.

This is in part because the reactions are multistage.

 

The importance of the initial reaction rate is to do with the rate controlling step.