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

The aim of this investigation is to test for the different types of biological molecules found in different types of food

Extracts from this document...

Introduction

Contents Page Introduction Page 2 Background Theory Page 3-4 Prediction Page 4 Materials and methods Page 5 Raw results Page 6 Analysis of results Page 6 Evaluation of materials and methods Page 6-7 Conclusion Page 7 References Page 8 Risk assessment sheet Page 9 Introduction The aim of this investigation is to test for the different types of biological molecules found in different types of food. We will be testing for starch, proteins, lipids and sugars. We will use nine (9) different types of food samples to test for all the above molecules in each food. When testing for different types of molecules in food, we use different types of food test. These tests are discussed below. To test for reducing sugars we will use the Benedict's test for Reducing Sugars (monosaccharides). Benedict's reagent is clear blue (from the presence of cupric copper ions, Cu++ ) but when combined and heated to boiling with a substance containing glucose in a chain form, the cupric ions are reduced to a cuprous form (Cu+ ) and then oxidized to form copper oxide (Cu2O). Copper oxide is a brownish-orange substance that is insoluble in water. Therefore, a positive reaction in a Benedict's test is the change of the clear light blue solution to an opaque orange-brown solution in a boiling water bath. This colour change indicates the presence of Glucose in a given solution. ...read more.

Middle

A benedict's test is then carried out which will be positive because the monomers are now free. Proteins Proteins are molecules, made up of amino acids. These amino acids contain carbon, oxygen, hydrogen and nitrogen. Sulphur is often present as well as iron and phosphorus. Each amino acid is made to the same design, with an amino group, a carboxyl group, a hydrogen atom, and a distinct R group (or side chain) all of which are bonded to an a-carbon atom. Amino acids are linked together in proteins by a peptide bond, made by the reaction of the carboxyl group of one amino acid with the amino group of the next. Polypeptides are just a string of amino acids, but they fold up and form the different structures of the proteins. The primary function of protein is to build body tissue and to synthesize enzymes. The biochemical test for proteins is the Biuret test. By adding some Biuret solution to a food sample; the presence of proteins would turn the food sample purple. Prediction I can predict that according to background knowledge that there will be some starch in the bread, sweet biscuit, the crisp and the cream crackers. The olive oil, nuts, the cream crackers and the crisp will also contain some lipids. It can also be predicted that the milk, eggs, nuts and cream crackers would contain some proteins. ...read more.

Conclusion

After the ethanol was added there was not an addition of water, the procedure for the emulsion test was not conducted the way it was meant to be. If this investigation were to be carried out again we would use a variety of foods such as meat, fish, different types of animal foods, this could help to compare the human diets and the animal diet. The results that would be obtained might be more or less the same, as all living organisms need the same nutrients, however might have different purposes in one's body. Time would also have to be an important factor. With enough time the experiments could be repeated and more accurate results would be taken. The method used could be used again however. The experiment would be repeated at least twice to obtained so reliable results; this will enable us to be aware of the mistakes in the procedures or recording of the results. Another way to improve this investigation could be to use raw materials not manufactured foods. If we used the ingredients contained in each food the results would be the same but it would help to explain and understand how certain foods contain certain nutrients. Conclusions It can be concluded that different kinds of food have different types of biological molecules and not all of them are the same. Eating different types of food which does not contain the same the biological molecules will provide the body with necessary nutrients. ...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. Synthesising organic and biochemical compounds - Preparation of Ethanol and Ethanoic Acid.

    2CH3CHO Ethanal (aldyhyde) +2 REDUCTION 2CH3CH2OH Practical three Equation In this practical, ethanol will be oxidised with the assistance of acidified sodium dichromate (VI) The following equation shows what will happen: C2H5OH CH2COOH Ethanol + oxygen ethanoic acid (Alcohol) (Carboxylic acid) What will happen, if micro- organisms are used as an alternative, will

  2. Catalyse Investigation

    and the inaccuracy was reduced (1 mm in 10=10%). Trying this out, I realised that the inaccuracy was still much greater than I would have liked it to be. I therefore weighed them too, to insure that all the pieces of potato had the same mass. This gives them the same volumes (presuming that the variations in density, caused

  1. Amylase Investigation

    Most theories concerning inhibition mechanisms are based on the existence of the enzyme-substrate complex ES. As mentioned earlier, the existence of temporary ES structures has been verified in the laboratory. Competitive inhibition occurs when the substrate and a substance resembling the substrate are both added to the enzyme.

  2. Testing foods for proteins, lipids, sugars and starch. Aim: To test a variety of ...

    Potassium Hydroxide 5. Ethanol 6. Sudan (111) Solution 7. Iodine solution 8. Seven Bottles of unknown solutions 9. Albumin (protein) 10. Mond Saccharides (glucose) 11. Lipid (cooking oil) 12. Starch 13. Pipette 14. Distilled water 15. 90� Water Bath 16. Test tube rack 17. Seven test tubes. Method: There where four tests in total that were carried out a

  1. Catalase investigation

    * pH buffer solutions of pH 2, 4, 6, 8 and 10 * 1 pair safety goggles * 1 white tile * 2 pipettes * Water * 1 Basin for water collection * 1 glass rod * 1 net

  2. Enzymes Investigation

    Subsequently, however, the German chemist Eduard Buchner discovered (1897) that a cell-free extract of yeast can cause alcoholic fermentation. The ancient puzzle was then solved; the yeast cell produces the enzyme, and the enzyme brings about the fermentation. As early as 1783 the Italian biologist Lazzaro Spallanzani had observed that meat could be digested by gastric juices extracted from hawks.

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