Module FB2C30 Experimental design lab activity
生物营养学报告代写 This is an extended practical investigation in the laboratory where you will determine the properties of an enzyme.
Introduction
This investigation is an extended practical exercise based around the analysis of an enzyme. The main learning objective, however, is for you to learn how to design experiments and work as a team. These are essential skills in the context of your future career – whatever path your professional life takes, team working will be a significant feature. In addition, you will not always be given a detailed, step-by-step protocol to follow in future laboratory (or, indeed, any other) work. In your final year research project, you will need to integrate protocols from others into your project strategy. After graduation, if you are involved in experimental work, the same will be true; those of you who go on to do a PhD or end up in corporate R&D will have to develop experimental protocols based on published papers. This module will start to teach you that process.
Organisation
This is an extended practical investigation in the laboratory where you will determine the properties of an enzyme. You will have an experimental design workshop one week before going to the lab where we will explore the principles of experimental design. Short briefing sessions will be given to introduce specific topics in the laboratory at appropriate times.
Aims and learning objectives 生物营养学报告代写
The emphasis of this practical investigation will be on experimental design, practical application and problem solving and by the end of the module you should be able to make informed decisions about how to go about investigating the properties of a given enzyme. The course will develop the following skills:
Experimental design
Practical laboratory skills
Problem solving
Data analysis and critical thinking
Teamwork
Self-motivation and time management
Characterisation of invertase
You will be provided with an enzyme solution, substrate solution and reagents to carry out an enzyme assay and to determine the protein concentration of the solution. Your laboratory will be adequately equipped to carry out the investigation. You, however, will design the details of the experiment and you will not be given a detailed protocol to follow. Instead, you will be given the principle behind the basic techniques that you will need and an indication of which measurements to make and you will be supported in your experimental design process by the teaching team. You will, however, retain a large degree of control over the experimental design process and it is likely that different teams will design different experiments.
You will be put into teams of three for the duration of the module. You do not have to be friends with your team-mates, but you do need to communicate clearly with them. The teaching team will support you in your team building and will actively develop this skill as the term progresses.
The Task
Your team will characterise the invertase activity in the solution provided. You will determine the following over the next few weeks:
The specific activity of the enzyme preparation against sucrose
The optimum pH and temperature for activity 生物营养学报告代写
KM and Vmax of the enzyme solution
The specificity of the enzyme on several carbohydrates
In order to allow you flexibility and control over your activities, we will not follow a precisely defined timetable and it is possible that some teams may progress at different rates – this is fine. It is also the case that many of you will have to repeat parts of the practical work – sometimes more than once – to get good results.
Enzyme assay basic procedure 生物营养学报告代写
The enzyme invertase hydrolyses the non-reducing sugar sucrose into the reducing sugars glucose and fructose. It is used in the food industry to manufacture invert sugar syrups and to produce the soft centres in confectionary products.
A basic procedure to assay your enzyme activity might be to incubate 1ml of substrate (in this case, 50 mM sucrose solution in buffer) with 0.1ml of enzyme for varying lengths of time before stopping the reaction by addition of 1ml of sodium carbonate (2% (w/v) in 0.5M NaOH). You can then determine the amount of reducing sugar released from the sucrose by a suitable assay such as the neocuproine assay.
You should ultimately cite your enzyme activity in units where 1 Unit is the amount of product formed (mmoles) per minute.
The neocuproine assay for reducing sugars
The concentration of reducing sugars is determined by the neocuproine assay based on reduction of copper ions.
You will need to prepare a standard curve of glucose from 0-0.5 mM.
To EACH standard concentration AND your enzyme assay time point samples:
Add 1 ml of 1mM copper chloride solution
Add 1ml of neocuproine solution
Add 1ml of sodium potassium tartrate solution
Cover cuvette with a cuvette lid and mix well by rapid multiple inversions before incubation at 55OC for up to 20 minutes. After incubation, read the absorbance at 450 nm against a suitable blank.
The BCA protein assay 生物营养学报告代写
Protein concentrations can be conveniently determined by the bicinchoninic acid assay using a standard curve of protein. You will be provided with bovine serum albumin as a standard and you will need a standard curve ranging from 0-2mg/ml.
The BCA assay is carried out as follows. Pipette 0.1ml of each calibration standard and the product dilutions into a series of tubes, add 2.0 mL of the BCA reagent to each tube and mix well. Cover and incubate tubes at 37OC for 30 mins then cool down to room temperature. Measure absorbance at 562nm against the zero-concentration calibration standard as your blank for the spectrophotometer. The reaction will continue as you perform the readings, so you need to complete the absorbance measurements within 10 minutes.
Assessment
The assessment will be based upon the practical investigation. You will write up your team’s investigation in the form of two reports. One will be given in part way through the investigation and feedback will be given before submission of the second report at the end of term. You will be given a proforma report to use – do not change the headings or structure of the report. The proforma is designed to allow you to efficiently communicate what you need to and for me to have a consistent basis to assess the group.
Your reports will be assessed on the basis of the clarity with which you have reported your experimental work, the accuracy of your results and your discussion of your data. A class practical session is not an ideal environment in which to obtain good quality data – yours will be subject to error. In each write-up you should explicitly:
Evaluate the protocol and identify the sources of error
Suggest ways of reducing this error through better experimental design
更多代写：多伦多经济代写 雅思作弊被抓 Educational psychology代写 Essay开头怎么写 代写多伦多论文 大学英语论文怎么写
合作平台：essay代写 论文代写 写手招聘 英国留学生代写
