• 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

    Investigate the water potential of celeriac.

    5 star(s)

    100 - I will calculate the percentage increase or decrease in mass. I will then plot these values on a graph against the concentration of sucrose solution. Constant factors - the temperature will be a constant factor throughout the experiment. It will be kept at room temperature at all times.

  2. Marked by a teacher

    Determining the Water Potential of Sweet Potato Tissue

    4 star(s)

    * % Change in mass = change in mass (g) Original mass (g) * Change in mass per gram = change in mass (g) Original mass (g) * Change in length per mm = change in length (mm) Original length (mm)

  1. Marked by a teacher

    Affect Of Varying Salt Concentration on Red Blood Cell Haemolysis

    4 star(s)

    Make up the saline solutions in the following concentrations using pipettes; carefully measure out the volumes of both sodium chloride and water to give all the concentrations required and place in separate test tubes. Sodium Chloride Concentration (%) Volume of Sodium Chloride (cm3)

  2. Marked by a teacher

    Investigating and testing for reducing and non-reducing sugars

    3 star(s)

    Redox Reaction Cu(( Cu(( Glucose is a monosaccharide. This means that the sugar solution is made up from many single sugar units that cannot be broken down into a simpler form. Monosaccharides are small, sweet, white, soluble and crystalline. Disaccharides are very similar, the are also small, sweet, white, soluble and crystalline.

  1. The mechanism of Negative feedback.

    being the rise of fall of temperature, which gives a greater degree of control. The corrective mechanism is the key component of homeostatic control. Homeostasis is a dynamic process; works by making continual adjustments to compensate for fluctuations of output.

  2. Investigate one factor that affects the rate of respiration of yeast

    I decided to use 10 minutes. 25cm³ of gas were produced. Then I tried using 2% glucose solution (10ml), it produced 20cm³. Although the two results are really close, I have decided that I will use the planned range (2%, 4%, 6%, 8%, and 10%), which I assume will give me sufficient evidence to support my prediction.

  1. The Effect of Sucrose Concentration on Osmosis.

    To do this, we need the percentages that are nearest to 0. From the table above, we can see that at the concentration of 1% sucrose, the potato gained 0.14 grams, and at 80 it lost 0.12 grams. We can assume that the potato will be losing mass, or at least gaining very small amounts of mass at 10% sucrose.

  2. An investigation to demonstrate osmosis using a potato

    The weight of the purple coloured slice will be noted before and after immersion as described above. Similarly the blue and pink coloured slices will also be weighed in tube 1. This process will be repeated for tubes 2 to 6 and the results will be noted in a table and then plotted on a line graph.

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