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Biology Coursework Catalase

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AS Biology Coursework Investigating the rate of enzyme activity with varying enzyme concentration Aim: To Investigating the Rate of Enzyme Activity with Varying Enzyme Concentration Introduction: Throughout this experiment I will be investigating the effect of enzyme activity whilst varying the enzyme concentration. I will be testing the activity of the enzyme trypsin on the substrate Casein whilst varying the concentration of trypsin. Trypsin is an enzyme that acts to degrade protein; it is referred to as a proteolytic enzyme or proteinase. Trypsin enzyme secreted by the pancreas in most animals, which functions in the digestion of proteins. Pancreatic fluid is introduced into the small intestine through several ducts. It contains trypsin and chymotrypsin, enzymes that split complex proteins into simpler components that can be absorbed and used in reconstructing body proteins. Trypsin is one of the three principle proteinases to break down dietary protein molecules e.g. Casein, to their component peptides and amino acids. Trypsin continues the process of digestion (begun in the stomach) in the small intestine where a slightly alkaline environment (about p H 8) promotes its maximal enzymatic activity. Trypsin is the most selective of all the proteolytic enzymes in terms of the restricted number of chemical bonds it will attack. ...read more.


Never fool around in the laboratory. Horseplay, practical jokes, and pranks are dangerous and prohibited. o . Always work in a well-ventilated area. o Work areas should be kept clean and tidy at all times. o Be alert and proceed with caution at all times in the laboratory. Notify the teacher immediately of any unsafe conditions you observe. o Dispose of all chemical waste properly. Never mix chemicals in sink drains. Sinks are to be used only for water. Check with your teacher for disposal of chemicals and solutions. o Know the locations and operating procedures of all safety equipment including: first aid kit(s), and fire extinguisher. Know where the fire alarm and the exits are located. Rate of Reaction Reactions with enzymes are up to 10 billion times faster than those without enzymes. Enzymes typically react with between 1 and 10,000 molecules per second. Fast enzymes catalyze up to 500,000 molecules per second. Substrate concentration, enzyme concentration, Temperature, and pH affect the rate of enzyme reactions. Temperature Enzymes have an optimum temperature at which they work fastest. For mammalian enzymes this is about 40�C, but there are enzymes that work best at very different temperatures, e.g. enzymes from the arctic snow flea work at -10�C, and enzymes from thermophilic bacteria work at 90�C. ...read more.


When the experiment begun I overcame this problem by continuously mixing the casein, this was to reduce the chance of any precipitate forming whilst not in use. At 0.4% concentration of casein an anomaly occurred- the time taken for the suspension to clear was 21.61s, as shown in the computer generated graph and the hand-drawn diagram a kink is present, disrupting the smooth flow of the curve. There are number of reasons why this anomaly occurred but none I can define as 100% correct. When diluting- calculating distilled water to trypsin ratios was correct but measuring the content is different all together. An error could have happen when drawing in the solutions from the beaker with burette, as a (mm) too much can cause this error. A similar error could have occurred with the inaccurate syringes that were supplied to measure the casein; this was a lack of professional resources/equipment. Improper cleaning of equipment- sterilisation of burettes and test-tubes may have lead to residues of previous equipments remaining in the medium and thus affecting the result. The use of large scale syringes and burettes leads to inaccuracy as the scale doesn't show the measurements in greater detail, e.g. In the process of measuring the casein with a 10ml syringe instead of a 5ml. Extracts taken from Encarta reference library ?? ?? ?? ?? Biology Coursework Page 1 of 13 ...read more.

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