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

Reducing and non-reducing sugars tests.

Extracts from this document...

Introduction

REDUCING and NON-REDUCING sugars tests. Aim: To distinguish which of the four unknown given substances are sucrose, maltose, glucose and water. Apparatus: Safety: For this experiment I made sure all the glassware was away from the edge of the table to avoid knocking them off and smashing them. Also I was careful whilst boiling the solutions and I was careful carrying to and from the water bath. I wore safety goggles throughout the experiment. Method: NON-REDUCING sugar. * Add 2cm of one of the unknown solutions into a test tube * Add 2cm of benedict's solution * Repeat this with each of the unknown solutions * Heat all the solutions in the water bath for 2 minutes Look at the colour of the solution if it remains the original blue colour of the benedict's solution then proceed with the test for REDUCING sugars. ...read more.

Middle

A and C and then proceeded to the REDUCING sugars test the results were as following: SOLUTION COLOUR AFTER NON-REDUCING SUGAR AND REDUCING SUGAR TESTS A RED C BLUE From my results I can tell: SOLUTION NAME A SUCROSE B GLUCOSE C WATER D MALTOSE Conclusion: Reducing or non-reducing refers to whether a carbohydrate gives a positive or negative test towards the weakly oxidizing Cu in benedict's solution. All reducing sugars contain free or potentially free aldehde. Only sugars that can't open to the carbonyl form are non-reducing. The Benedict's test allows us to detect the presence of reducing sugars (sugars with a free aldehyde or ketone group). All monosaccharides (carbohydrates that can't be hydrolysed to simpler compounds) ...read more.

Conclusion

We know that sucrose is made up of one glucose molecule and one fructose molecule glycosidicaly bonded. After hydrolysing to break the glycosidic bond to its constituent monosaccharides it then gave a positive test for reducing sugars (benedict's test). Solution B was glucose as it formed a red precipitate, which showed it was a monosaccharide solution. Solution C was water it also remained its original blue colour however after hydrolysing it still gave a negative test for reducing sugars (benedict's test). Finally, solution D was maltose as it left a green precipitate. Maltose is also a disaccharide, as previously explained not all disaccharides are non-reducing; however they are not as reducing as monosaccharides. My final conclusion is that the reducing sugars include all monosaccharides, glucose and fructose and some disaccharides, maltose. Tegan Gowlland ...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 Exchange, Transport & Reproduction section.

Found what you're looking for?

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

Here's what a teacher thought of this essay

3 star(s)

***
The author has a sound understanding of the biochemistry behind this straightforward experiment. However, muddling up the tests for reducing and non-reducing sugars suggests that the finished write up was not checked. Greater attention to detail generally would have improved the quality.

Marked by teacher Adam Roberts 05/09/2013

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 Exchange, Transport & Reproduction essays

  1. Marked by a teacher

    An Investigation into the Water Potential Of Root Vegetables.

    4 star(s)

    I plotted my results on a graph (overleaf) to find the concentration o the isotonic solution for each vegetable. I then found the water potential of the vegetables by referring to a graph showing water potential (kPa) at various sucrose solution concentrations.

  2. Marked by a teacher

    Mr Chips: Investigation to find an isotonic solution for potatoes

    4 star(s)

    so they should be kept away in a safe place * Be careful of glassware Results Table 3 Recorded weight of potato, before and after experiment Concentration NaCl solution % Initial Mass (g) Final Mass (g) 0.0 1 4.02 4.12 2 4.21 4.44 3 4.11 4.37 0.5 1 4.23 4.20

  1. Marked by a teacher

    Investigating and testing for reducing and non-reducing sugars

    3 star(s)

    However, due to condensation reactions forming glycosidic bonds (due to the loss of water), disaccharides are formed from two monosaccharide units. If the copper sulphate within the Benedict's solution is reduced it can be measured quantitively.

  2. To compare quantitatively the concentrations of glucose and other reducing sugars in samples of ...

    Risk assessment * Wear a pair of goggles as Benedict's solution is harmful. * Do not splash the test tubes when putting them in and out of the water bath, as the water is hot enough to burn. * Let the solutions cool sufficiently in a test tube rack before

  1. Fermentation of different sugars by yeast.

    See example below. Yeast Yeast is a micro-organism which breaks down sugars to form alcohol and Carbon Dioxide. Variables * Temperature * Yeast Concentration * Type of Sugar * Sugar Concentration The variables that I will control are temperature, yeast concentration and sugar concentration.

  2. beetroot experiment

    The fact that because it is known that 70% of membrane is protein, the pigment is heat labile and this is why it is fragile to heat. Two main major reasons of the effect of temperature that had had caused this kind of trend is that at higher temperature, i.e

  1. Investigating Water Potential Of Potatoes.

    Measure them to the same dimension using a ruler. Write down the length in a table. 3 Use a measuring cylinder to place 50cm� of 1molar sucrose solution in to a sample tube. Label the tube 4 Place 50cm� of 0.5 molar sucrose solution in to another tube and label it.

  2. To find out the factors affecting the refractive index of liquid by using different ...

    I want to change the temperature of the solution. I can use an electric heating stick. Connect the power supply to the main supply. Turn the voltage to 13V in order to more it work in its fastest rate, use wires to connect the power supply to the plug of the heating stick.

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