Self-Assessment: Peer Review Criteria Prior to doing the alterations (with respect to feedback) I would have said all these categories would have needed some improvement but now I believe the report has mostly answered the questions below. The results section was only satisfactory since the calculated equations aren’t given. For the purposes of this item they weren’t calculated but cannot be accounted for. Does the title clearly tell the reader what the article is about? Is the abstract sufficiently informative, especially when read in isolation? Is the article clearly written, free from spelling and grammatical mistakes, and formatted correctly? Is the organisation of the article satisfactory? Eg are results only presented in the discussion section? Is sufficient background provided in the introduction and are the aims of the article clearly stated? Is the description of the materials and methods adequate to permit someone else to repeat the study/experiment? Do the experimental methods and data address the aims and hypotheses? Are the results clearly presented? Does the evidence presented (from this or other papers) support the ideas discussed? Are topics discussed consistent with the aims, background and hypotheses? Are references provided to support all appropriate claims or statements in the paper? Absolutely Absolutely Absolutely Absolutely Absolutely Absolutely Most ly Most ly Most ly Most ly Most ly Most ly Satisfactory Satisfactory Satisfactory Satisfactory Satisfactory Satisfactory With improvement With improvement With improvement With improvement With improvement With improvement No Absolutely Absolutely Absolutely Absolutely Absolutely Most ly Most ly Most ly Most ly Most ly Satisfactory Satisfactory Satisfactory Satisfactory Satisfactory With improvement With improvement With improvement With improvement With improvement No No No No No No No No No No Reflection on changes: With the alterations made I believe the report appeals to a wider audience and the chances of misinterpretation have been reduced. Beforehand it may have been directed towards a specific audience with assumed knowledge on the subject matter. As per the helpful feedback received I have introduced a sentence to the ‘Abstract’ and restructured certain sentences to ensure the communication is concise. I then deliberated with my own assessment making sure that the major notes were implemented – IE labeling acronyms on first cite. After reading the final product it can be seen that the feedback and self-assessment have provided valuable insight into the communication aspect of the report. The process of using the information and translating it to the written text was simple but not practiced prior. It becomes clear the importance of the principles we have discussed in class and their effect on the appeal to audiences. Determination of Glucose and Sucrose in Sports Drinks Communicating in Science S4293404 S42934048 SCIE3001 1|Page Abstract Enzymes react sporadically, causing fluctuations and increases in cellular activity. They are used as a mechanism of control for which cells can catalyse priority specific tasks. Through spectrophotometry it can be observed that the presence of NADPH at certain time intervals can indirectly gauge enzymatic reactions occurring – additionally the products formed as a result. Two sports drinks were assigned samples and tested for two types of carbohydrate – sucrose and glucose. The enzyme reactions were coherent in respect to concentration levels. This experiment therefore tested for the presence of either sucrose or glucose and their concentrations in sports drinks with respect to the nutritional labels given. The manufacturer’s published label and the results of the experiment were indicative of accuracy. Introduction Enzyme induction is a process by which cells regulate protein synthesis via substrate mechanisms. Activation energy is the required state before any reaction is initiated . The presence of enzymes lowers the threshold thus liberating a lower energy pathway for the action potential to propagate along. Enzymatic control does not impede/contribute to the reaction equilibrium and any changes to reaction energy that may occur. Substrates are a counterpart to enzyme control which when combined results in a product. In some cases, enzymes require the presence of another enzyme (coenzyme) or co-factor (for example the ions; Mg2+, Cu+ and Mn2+) to facilitate the reaction. (Timberlake, 2001). Enzyme assays are used to measure enzymatic activity in reactions. By measuring either the consumption of substrates or the amount of product being produced allows enzyme statistics to be calculated. In this experiment, the continuous assay used involved light to determine the presence of molecules – spectrophotometry. The type of molecule determines the wavelength’s absorbency. For example, NADP+ (Nicotinamide adenine dinucleotide phosphate) cannot absorb strongly at 340nm whereas NADPH (reduced Nicotinamide adenine dinucleotide phosphate) can. Therefore molecules that disappear and reappear throughout the entire reaction can be measured spectrophotometrically. The aim of the experiment is to test for the presences of these molecules and measure their concentrations respectively. S42934048 SCIE3001 2|Page Reaction Sequence of the Experiment Sucrose + H2O (water) à D-glucose + D-fructose Enzyme: Invertase D-glucose + ATP (Adenosine Triphosphate) à Glucose-6-phosphate + ADP (Adenosine Diphosphate) Enzyme: Hexokinase Glucose-6-phosphate + NADP+ (Nicotinamide adenine dinucleotide phosphate) à 6-phosphogluconate + NADPH + H+ Enzyme: glucose-6-phophate dehydrogenase Methods/ Experimental Two sport drinks were assigned samples, Powerade and Gatorade. An additional 6 standard drinks – 3 sucrose and 3 glucose- plus 2 blanks were included. Samples were labelled and prepared with dilutions of sucrose and glucose including a buffer where needed. Using spectrophotometry, wavelength absorbances and (indirectly) NADPH concentrations were calculated and recorded. TEA and Citrate buffers were used along with incubators to ensure efficiency of the multi-step enzymatic reaction that followed. Refer to lab manual for detailed methodology. Results Table 1’s absorbance difference column shows the change in NADPH concentrations at the beginning and end of the experiment. No significant shifts are seen in the data and correlates closely with the enzymatic reactions occurring after the final 2minutes (A1-A2 columns). In Figure’s 1 and 2 the data was plot using the standard data only which in turn allowed the calculation of the sample sports drink figures. This was achieved using the equation for the line of best fit for the standard data – y = 0.168x and y = 0.1751x respectively. The obtained data was then entered onto the same plot. S42934048 SCIE3001 3|Page Table2 shows how the absence of the initial enzyme effects the data as it is not needed to be broken down. This can be seen by comparing the two A1 columns for Table 1 and 2. The figures in Table 1 are mostly negative whereas Table 2 depicts positive data. A2 of Table 2 follows a similar trend pattern to Table 1’s A2 which is indicative to the amount of enzyme activity at the time. Table1: Sucrose and Glucose Assays Sample A1 (340nm) A2 (340nm) Absorbance difference (A2 - A1) Blank 0 0 0 2mM -0.002 0.421 0.423 4mM -0.001 0.634 0.634 6mM -0.004 1.048 1.052 Gatorade -0.003 0.364 0.367 Powerade 0.012 0.315 0.327 Sample data compared with standards using absorbance 1.2 y = 0.1684x 1 Standards 0.8 0.6 samples 0.4 Linear (Standards) 0.2 0 0 2Concentration 4 (mM) 6 8 Figure 1: Compared absorbencies in relation to sucrose concentration levels of standard and samples Table2: Glucose Assays Sample Blank 2mM 4mM 6mM Gatorade Powerade A1 (340nm) A2 (340nm) Absorbance difference (A2 - A1) 0 0 0 -0.002 0.328 0.33 0.012 0.844 0.832 0.003 1.003 1 0.009 0.087 0.078 0.006 0.083 0.77 S42934048 SCIE3001 4|Page Glucose standards compared with sample data using absorbance 1.2 y = 0.1751x 1 0.8 Standards 0.6 Samples Linear (Standards) 0.4 0.2 0 0 2 4 Concentration (mM) 6 8 Figure 2: Compared absorbencies in relation to total glucose concentration levels of standard and samples Table3: Sucrose and Glucose Content of Sports Drinks Sports Drink Gatorade Sucrose Glucose (g/100 mL) (g/100 mL) 5.48 0.792 Powerade 4.79 0.801 Calculations S42934048 SCIE3001 5|Page Discussion The enzyme reactions were observed based on the breakdown and production of energy. Using energy it is possible to determine the rate at which enzymes function. The basis for experiment was to test for the presence of NADPH (energy) at timed intervals. A pre-determined wavelength of 340nm was used. Recordings for NADPH absorbencies were recorded in Tables 1 and 2 as ‘A1’ and ‘A2’ columns. Figure 1 and 2 used several standardised figures – 0mM, 2mM, 4mM and 6mM – which allowed a comparative analysis of the sample data. By performing the steps outlined in the lab manual, two assays were completed successfully. Table1 presents recordings that were used to compare sucrose and glucose levels whereas Table 2 refers only to naturally occurring glucose levels. The difference between the two is needed as they both provide naturally occurring glucose for an immediate energy response in the body – Table 2. Sucrose is made up of ‘fructose’ (also known as a fruit sugar) and glucose. In order for glucose levels to be obtained the sucrose was broken down using hydrolysis. (Marieb, 2007). The fructose within the sucrose is needed as it provides a delayed energy source via the liver’s glycogen cycle due to its lacking adherence initially. Table 3 shows the sucrose/glucose grams per 100mL for each sample. The experiment proved to coincide with the nutritional information provided by manufacturers with minute variation (refer to Table3 and Appendix 1). Repetition would ensure complete accuracy but deviations are likely to occur otherwise. The enzymes used were assumed to be in an active state after the 15minute interval and higher concentrations would have ensured efficiency. In addition, the manufacturer data is an average and varies from bottle to bottle from the factory S42934048 SCIE3001 6|Page References Timberlake, KC 2007, General, Organic, and Biological Chemistry, Pearson Prentice Hall, New Jersey. Hoehn, K & Marieb, EN 2007, Human Anatomy & Physiology, Pearson Benjamin Cummings, San Francisco. Appendix 1. Manufacturer Label: Powerade is 7.6g/100ml of carbohydrate with 6g of sucrose included. Gatorade is 6g/100ml of carbohydrate with 5.5g of sucrose included. S42934048 SCIE3001 7|Page