Page
  1. 1
    1
  2. 2
    2
  3. 3
    3
  4. 4
    4
  5. 5
    5
  6. 6
    6
  7. 7
    7
  8. 8
    8
  9. 9
    9
  10. 10
    10
  11. 11
    11
  12. 12
    12
  13. 13
    13

To investigate and compare the activity of immobilised enzymes against enzymes free in solution at a range of different concentrations.

Extracts from this document...

Introduction

Biology Coursework Planning Aim: To investigate and compare the activity of immobilised enzymes against enzymes free in solution at a range of different concentrations. Introduction: Lactose: C12H22O11, found in the milk of mammals, is a disaccharide composed of one glucose and one galactose molecule joined by a beta 1:4 linkage. C12H22O11 C6H12O6 + C6H12O6 Lactose glucose galactose Draw out structure from sheet . To utilise lactose an organism must posses a specific enzyme (lactase) which catalyses the hydrolysis of lactose into glucose and galactose. To fully utilise lactose a organism must also have a second enzyme which subsequently converts galactose into glucose. Among adult humans, the ability to digest lactose is actually relatively rare (confined particularly to whites of Northern European ancestry) and lactose intolerance occurs due to an absence of production of the human lactase digestive enzyme which catalyses the hydrolysis of lactose into its constituent monomers. Enzymes Enzymes are biological catalysts. A catalyst is a substance, which speeds up a reaction without getting used up itself. Industrial processes use catalysts to speed up production, reducing the need for high temperatures and pressures. The human body temperature is 37C, and without catalysts the reactions would be too slow to sustain life. Since there are thousands of different reactions happening in cells, and each requires a specific enzyme, enzymes must be made of a type of chemical which can vary enormously in structure, amino acids. There are roughly 20 different amino acids, which can be linked in infinite amount of ways. This means that the primary and tertiary structure of enzymes can show the variability needed to achieve specificity, particularly upon the shape of a small part of the enzyme molecule where the enzymes actually come in contact with the substrate molecule, the active site. This is a small 'cleft' on the enzyme surface, where certain amino acid residues are exposed. The substrate molecule fits into the active site and interacts with these amino acids by ionic and hydrogen bonding, forming and enzyme-substrate ...read more.

Middle

Perhaps there was a temperature increase, as the milk had been left out during the experiment when the 10% result was taken, making the rate faster, so that the 100% and 10% result had little difference between them. This could be improves in the final experiment by measuring the temperature and pH of the milk before the experiment begins, in both the immobilized and free in solution lactase enzymes. Another reason, that could have caused, this result, was that the syringe barrel was not cleaned out properly between results, which might have meant that different enzyme concentrations, may have been mixed. Other areas, that I think would improve the experiment, is when making the beads leave them for a set amount of time to harden so that they do not clump together, and I should make sure that the mixtures of sodium alginate and lactase are mixed together well. The beads often came out at different sizes, especially when forming my first set of 100% concentrated beads, which might have meant that small beads were penetrated faster, which meant more enzyme substrate complex's were formed quicker, increasing the rate. The number of beads, therefore also varied in the syringe barrel, within the 5cm3 mark. I think I need to make sure the beads out into the barrel, are all of similar size, this will also prevent beads getting stuck in syringe outlet restricting the flow of milk droplets. I think that more than one set of results should be taken for each reading so that an average can be taken, for a fairer experiment, decreasing the chance of human error, and making sure that results, can be determined as anomalous fairly, such as the 0.1% results found above. Final experiment: Apparatus: * 4cm3 Lactase (2cm3 for the immobilised enzymes and 2cm3 for the enzymes free in solution) * 8cm3 Sodium Alginate solution, made up in distilled water * 100cm3 of 2% calcium chloride solution * Clinistix * 10cm3 plastic syringe and syringe barrel (with measurement markings) ...read more.

Conclusion

This could be improved, by using more advanced type of glucose detecting sticks to measure the percentage of glucose conversion. This will give a quantitative, which would produce more accurate tables and graphs. I could use a set time for to check how much is converted. This would prevent problems such as interference of the beads and lactose and galactose molecules, blocking the glucose molecules from the end of the syringe outlet. * Another difficulty, was in the rate of drops flowing from the syringe barrel, was hard to control, alternative apparatus, should be looked into, e.g. a burette * I could look further into the structure and weights of the molecules produced and used, to see if e.g. weight of the molecules, effects how fast they reach the end of the syringe, perhaps, if glucose is lighter molecule than galactose, than it will not sink to the bottom of the syringe as quickly. This might mean that I should measure glucose conversion, by sticking the glucose stick into the beaker beneath the syringe outlet, after it has been stirred at a certain time, rather than the drops from the syringe outlet. * I could do more detailed percentages especially exploring between 10% and 100% where the largest gradients were produced. The experiment could be explored further, by changing a different variable, such as temperature or pH, to determine and prove these effects experimentally, to broaden my understanding of lactase enzymes further. I could explore what the activation energy, denaturing and optimum rate temperature/pH would be. Health and safety had to be considered in this experiment, here are some of the guidelines I followed, as calcium chloride is irritating to the eyes, skin and respiratory system, we tried to make minimum skin contact and limit the possibility of inhalation, by careful and conscious handling of the products. Small amounts of lactase were left out for use, so there was none left over, so to avoid any drying up and causing dust formation, which could provoke asthma or hay fever, any spillages were cleared up quickly with water. ...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. Induction of beta-galactosidase

    all test tubes A high concentration of ONPG in one area of the test tube will require more ß-galactosidase An area of high concentration will be paler yellow than the rest Systematic, as if none of the tubes are shaken, they will all have an irregular dispersion of ONPG Temperature

  2. To find out how different concentrations of sucrose solution affect the incipient plasmolysis of ...

    0.03 0.00 -0.02 -0.07 -0.11 Percentage Change (%) 1.97 0.00 -1.41 -5.00 -7.75 Solution (Molar) 0.3 0.4 0.5 0.6 0.7 Before After Before After Before After Before After Before After Run 1 30 32 30 29 30 28 30 28 30 25 Run 2 30 31 30 30 30 29

  1. Marked by a teacher

    How does the concentration of enzymes affect the breakdown of starch by a-amylase in ...

    4 star(s)

    This means that if the range bar is short, the average result is fairly accurate, ass all the values obtained are close together. If the range bar is long, however, the values obtained of that concentration are far apart, which means they will not be as accurate.

  2. Marked by a teacher

    Find out if enzymes work faster or slower at different temperatures.

    5 star(s)

    Neutrase's substrate is called "casin". Casin is the white pigment found in Marvel milk. Therefore, if we break down the casin with the neutrase we will be left with a colorless mixture. Like all living organisms enzymes have conditions in which they will work best known as the optimum temperature and pH.

  1. Investigating the effect of temperature on the activity of free and immobilised enzymes.

    An enzyme substrate complex is the compound formed when the substrate is attached to the active site; it is only in this form for a short time while the substrate is being broken down. Lactase Lactase (?-Galactosidase) breaks down lactose, the sugar in milk, to galactose and glucose.

  2. Marked by a teacher

    "To Clone or Not to Clone- That is the Question".

    4 star(s)

    Although at present, human cloning is much too difficult and expensive for it to be taken to a larger scale, but as science progresses, anything may be possible and cloning could become a common practice. Also, rewinding back to the beginning when the situation of Joseph Mengele was mentioned: what if it does become possible to create armies of clones?

  1. The main aim of this experiment is to investigate how varying the concentration of ...

    During the course of this experiment I have noticed that when I poured the various amount of solution (i.e. 20 cm 3) it nearly filled the whole of the test tube. This caused a few problems. The biggest of all was that when you shake the test tube throughout the course of the experiment.

  2. Biology Coursework on Enzymes.

    My coursework, which is on enzymes, will investigate the variable of pH. Therefore my aim will be: Aim: I am investing the effect of pH on the activity of the enzyme Trypsin; this is when this enzyme reacts with the substrate Caesin.

  • Over 180,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work

Marked by a teacher

This essay has been marked by one of our great teachers. You can read the full teachers notes when you download the essay.

Peer reviewed

This essay has been reviewed by one of our specialist student essay reviewing squad. Read the full review on the essay page.

Peer reviewed

This essay has been reviewed by one of our specialist student essay reviewing squad. Read the full review under the essay preview on this page.