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

An experiment to investigate the action of saliva on starch:

Extracts from this document...

Introduction

An experiment to investigate the action of saliva on starch: Research question Do enzymes in our saliva break up starch into simple sugars (mono- or disaccharides)? Introduction Enzymes are globular proteins, which act as biological catalysts. They speed up reactions by binding to a substrate, such as for example the enzyme amylase, which binds to starch (a polysaccharide) in order to break it down into di- and monosaccharides. They are present in all organisms in thousand of different forms, most enzymes specific to only one substrate. An enzyme has an active site, at which it binds to a substrate, which is specific to its shape. An example for this is the enzyme amylase which catalyses the breakdown of starch, a polysaccharide for example found in potatoes. When it is digested by amylase, it will be broken down into disaccharides, which are sugars such as maltose. Then another enzyme, maltase, will break the disaccharide down into glucose, which is the monomer starch is made of. Starch is a carbohydrate consisting of a large number of glucose units joined together. It is produced by all green plants as an energy store. ...read more.

Middle

Draw in a little air and quickly and thoroughly mix the contents of the syringe by inverting it two or three times. 7) Hold the syringe vertically and immediately squeeze the plunger carefully to expel one drop of the mixture into the first drop of iodine solution on the tile. Do not let the tip of the syringe touch the iodine solution. Note the time. 8) Continue to test single drops of the mixture at intervals of 30 seconds until the iodine solution shows no further change in colour. 9) Now expel 1cm3 of the remaining mixture in the syringe into a test-tube. Test this for the presence if reducing sugars using Benedict's solution. Put it into a water bath and leave it for 10 minutes. Then take it out. 10) Ten expel another 1cm3 of the remaining mixture in the syringe into a test-tube. Test this for the presence of reducing sugars, using Benedict's solution. Put it into a water bath and leave it for 10 minutes. Then take it out again. ...read more.

Conclusion

* 3) What conclusion can you draw from the results of the tests in steps 9 and 10? - The solution turns brick red. That means that the starch in the solution has been broken down to reducing sugars by the amylase in the saliva. * 4) What test should you perform on the original starch suspension before you can be confident of your answer to question 3? -Iodine test to see if starch has completely been broken down. If it turns black blue, starch is still present! * 5) How are the properties of saliva affected by boiling? - The enzyme amylase in saliva is denatured and so the starch in the saliva stays unchanged * 6) Saliva normally acts on starch at body temperature (37�C). If you had carried out the whole experiment at this temperature, what difference would you expect this to have made to the results you obtained? -The results would have been much faster. The colour would change much faster for example from blue/black directly to navy blue or dark purple instead of changing much slower. (as shown in the result table) The experiment would be much faster to do and to finish. Biology-SDH by Rebecca Kriegbaum ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our International Baccalaureate Biology 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 International Baccalaureate Biology essays

  1. Bacteria and Cleanliness. Question: Among the insides of a toilet, dishcloth, sink, and a ...

    cleanest, we never completely disinfect the dishcloth by placing it in a bleach solution for about ten minutes. Error Analysis: This experiment did require minor mathematical computations, and error was eliminated by double-checking the arithmetic in a calculator. Moreover I utilized an automatic cell counter that eliminated any error in the counting of bacteria colonies.

  2. Penicillin - its discovery, properties and uses.

    The article showed that penicillin does not appear to be related to any chemotherapeutic substance in present use, and is particularly remarkable for its activity against the anaerobic organisms associated with gas gangrene. The news was as explosive as the prose is calm and flat.

  1. Isotonic Point of Potatoes

    A general pattern that was observed in the data was that as the concentration increases till 0.25M the change decreases after which, the change becomes negative and increases from there on. This also shows that the isotonic point is somewhere between 0.25M and nearer to 0.25M.

  2. The Effects of Salinity on Wheat Germination

    The experiment itself poses no great danger and it can be assumed that the safety, environment and possible costs should an accident take place are ? 3 meaning that there is an unlikely risk of an insignificant incident and/or a rare risk of a minor accident taking place.

  1. Research Project . Should Research Into Biological Warfare Continue?

    This means it affects the nerve cells. For example interfering with the impulse at the synapses and causing paralysis. It is one of the most poisonous naturally occurring substances in the world, and it is the most toxic protein. Though it is highly toxic, it is used medically and in

  2. Determining the rate of action of an enzyme

    The condition of the liver will determine the amount of surface area exposed to the substrate and hence be the definitive factor in this investigation. Accordingly, the rate of action of the Catalase will be greatest when the liver is ground, it will be followed by the sliced liver and then the whole liver.

  1. Sleep is a normal part of human life. Investigate the neurobiological basis of normal ...

    can result in behavioural problems, permanent sleep disruption, decreased brain mass, and an abnormal amount of neuronal cell death. REM sleep seems to be important for development of the brain and occupies the majority of sleep time of infants who spend most of their time sleeping.

  2. Experiment-Effect of Temperature on the Action of Amylase Enzyme

    AIM To investigate the effect of temperature on the action of amylase enzyme HYPOTHESIS The rate of amylase enzyme activity increases with temperature because they will gain more energy to break down the starch until it reach the human body temperature.

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