• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

The effect of pH on the activity of the enzyme Amylase

Extracts from this document...


The effect of pH on the activity of the enzyme Amylase Aim :- To find the effect of pH on the activity of the enzyme amylase. An enzyme is a type of protein found in all living cells. Enzymes act as biological catalysts, breaking down substrates without needing a high temperature, allowing all the chemical reactions of metabolism to take place, regulating the speed at which they progress, lowering the activation energy and providing a means of controlling individual biochemical pathways. Enzymes owe their activity to the precise three-dimensional shape of their molecules. According to the 'lock-and-key' hypothesis, the substrates upon which an enzyme fit into a special slot in the enzyme molecule: the active site. A chemical reaction takes place at this site (hydrolysis - the addition of water in order to break a peptide bond between two amino acids) and the products are released, leaving the enzyme unchanged and ready for re-use. Enzymes are very specific in relation to the substrates with which they work, and are normally only effective for one reaction or a group of closely related reactions. They function best in particular conditions of temperature and acidity (pH), and their action can be slowed or stopped by inhibitors. Extracted from 'Oxford interactive Encyclopedia' by TLC The graph shows that when the pH is changed the reaction rate of the enzyme changes too. ...read more.


At some point all the enzymes are denatured and the reaction rate falls to zero. Prediction More specifically to our experiment we are using the enzyme Amylase, this is a enzyme found in the salivary glands, pancreas and small intestine. Amylases, act on starch, breaking down (hydrolysis) to produce glucose and other sugars, other uses are in textile manufacture, in some biological detergents, and baking, to produce lighter loaves. In our experiment we will be measuring how quickly the enzyme Amylase catalyses (breaks down) the substrate starch (a polysaccharide) into the product Maltose (a disaccharide). The Maltose produced will be a reducing sugar and to test this with our final product we will be using Benedict's solution. With this information I can predict that the optimum pH of Amylase will be of pH 7. I predict this because generally most enzymes work at a neutral pH, where there are least Hydrogen ions for less interference. If amylase was of a high deviation from a neutral pH it would be unlikely that it would be found in the small intestine, the small intestine contains fine glandular tissue (Villi) used for absorbing nutrients from broken down food and any high pH would be likely to destroy the fine tissue. ...read more.


Specifically to this experiment we must keep the Starch suspension, buffers and amylase suspension at a constant of 37�C. Doing so will keep my results constant and accurate. Substrate concentration:- Must remain constant because as the concentration increases the reaction rate does also. This is because as the substrate concentration increases the enzymes can bind with the substrate more frequently. I shall keep the volume of substrate the same each time this should produce accurate results. Variables that I will be altering:- I will be altering the pH in order to see how it affects the reaction rate of enzymes. Observations and Measurements I will use a stop watch to measure the time the enzyme takes to convert starch (a polysaccharide chain) to maltose (a disaccharide) I will test the end solution with Benedict's solution to see if maltose is definitely produced. Repeats I shall repeat the experiment 3 times this shall produce an accurate set of results. This will insure that any anomalous results obtained will be more spread out. Accuracy In order to achieve a high level of accuracy I have made the following choices:- * All glass wear used for measuring e.g. measuring cylinder will be of a grade B or higher. * Safety The usual safety precautions must be enforced for example safety goggles and clear walkways. Specific care must be taken when handling the acidic pH as they may burn the skin. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our AS and A Level Molecules & Cells section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related AS and A Level Molecules & Cells essays

  1. Marked by a teacher

    How does the pH affect the activity of amylase

    3 star(s)

    Moisten immediately and remove completely. Dissolve in water before disposal Enzymes should be dissolved in water before discharge into the sewage system. If you have been exposed to dust, plenty of tap water should be applied to the exposed areas: skin, eyes, clothing (wash as usual).

  2. How does pH affect the Denaturation of enzymes Starch and Amylase.

    So I set up another tube of pH 12 at 5ml, and added 5ml starch. I added the 5ml of amylase and gently stirred it. I was going to test if I needed to add more drops of iodine to make the concentration of iodine stronger in the solution.

  1. An investigation into the effect of pH on the starch hydrolysis of fungal and ...

    these are acidic and also repel the substrate. This therefore causes a drop in reaction rate. It is very important to control the other variables that can affect the rate of amylase activity so that the only factor that affects the activity of the amylase in this investigation is the pH.

  2. 'Investigating how temperature affects the rate action of the amylase enzyme on starch.'

    The results below and including 75�C are said to be 'okay'. Analysis: Even though my results were declared faulty, I will analyse the results that I achieved successfully. I predicted in my hypothesis that the optimum temperature would be at around 45�C.

  1. Investigating the effect of pH on the activity of an enzyme.

    So all test tubes have to be put in the same water bath conditions for accurate results. * Same size of exposed photographic film: This has to be the same length for all test tubes if it is shorter enzyme will react quicker as there is less substrate than if

  2. Investigating the Effect of pH on Enzymes

    It puts forward the idea that the active site does not completely correspond to the shape of the substrate. Instead the active site is more flexible and is therefore able to mould itself around the substrate. When it has bound closely the reaction then can occur forming the new products,

  1. The effect of pH on an enzyme - Fungal amylase.

    The variables: There are four factors that affect the rate of the reaction. Increasing or decreasing any one of them has an effect on the rate of the reaction and the time taken for the reaction to be completed. They are: 1.

  2. The effect of Electromagnetic Fields on Enzyme Activity

    a possible replacement for the more dangerous x-rays which were very useful in medical and therapeutic equipment. The interaction of electromagnetic fields with the human anatomy is a very complex matter. Most sources which were used for this research agreed with the fact that the most dangerous aspect of an electromagnetic field or radiation is the magnetic component.

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work