The Aseptic technique developed to prevent contamination from unwanted microorganisms. For example when you want to set up a bacteria culture the only bacteria you would want on the petri dish is the one you are studying and therefore you would use the aseptic technique to ensure there is no contamination. We will run through how to correctly move bacteria from a broth onto a petri dish using the aseptic technique Before the procedure
The Procedure
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There are two ways in which a virus can reproduce/multiply inside a cell.
There are many different ways drugs stop viruses by affecting various parts of the viruses life cycle. some of the main ones include.
Synthetic biology is a new up and coming strand of biology defined as 'designing and constructing biological devices, biological systems, and biological machines for useful purposes' this brings about a wide range of new possibilities, especially when looking into creating new 'unnatural' Amino acids. there are only 20 naturally occurring amino acids even though there are 61 codons excluding stop and start codons. scientists are therefore able to 'code' for new amino acids which can lead to genetic alterations to organism.
https://www.newscientist.com/article/dn22167-synthetic-upgrade-for-fruit-flys-dna/ This article from the New Scientist reviews scientist ability to 'hack into' the genetic code of fruit flies and use them to create new proteins by editing the amino acids and making them create some 'unnatural' amino acids. which can then be used to code for and create new proteins which in theory could be used to create organism with new or improved properties such as a "bulletproof fly" Objectives: The objective of this experiment was to measure the initial rate of reaction for various concentrations of the enzyme Trypsin as it breaks down the Lactose in milk. We did this using a colorimeter to measure the amount of light which can pass through the milk-trypsin solution. As the trypsin breaks down the lactose the milk which was previously cloudy becomes colourless and more and more light can pass through the solution. Equipment:
Procedure
Analysis of results: Graph showing the rate of reaction for the lactose to completely break down in the different concentrations of trypsin Here is a table of my results followed by a graph of my results Conclusion:
As you can see from the graph of my results, as the concentration of enzyme (trypsin) increased so did the initial rate of reaction. This is because with more trypsin in the milk solution, more enzymes are meeting the lactose substrate at a faster rate and binding with the enzymes active site to produce enzyme-substrate complexes and breaking down the lactose. The increased rate of the lactose breaking down means that the milk will turn opaque faster and our dependent variable (the initial rate of reaction) will increase. Questions: 1. What were the independent and dependent variables in this investigation? The Independent Variable was the concentration of trypsin and the Dependent Variable was the initial rate of reaction. 2. Why is it important to measure the initial rate of reaction rather than an average rate over a longer time period? Because at the end of the experiment when the reaction is complete we get a few results where no light is absorbed and 100% of the light passes through the solution, this is unchanging so the rate of reaction is 0 and this would affect the average rate of reaction and make it unreliable. 3. If the surface of the cuvette is scratched, it can result in a greater absorbance of light. if the cuvettes used for the reaction was scratched (but the reference cuvette was not) would this give a random or systematic error? explain your answer. It would give an systematic error since it is an error which would occur for all the data results that use the scratched cuvette and the error would be constant. whereas as random error would only occur to a single data point, an example of this would be if for one of your tests you put in extra trypsin solution by mistake causing the initial rate of reaction to be higher, but this error would only occur once and not effect the data points unlike a systematic error. 4. Suggest two variables that would normally be controlled in enzyme-catalysed reactions but have not been specifically controlled in this investigation. Explain why they would usually be carefully controlled and suggest how this could be done. Ph would normally be controlled in a experiment using enzymes as they greatly affect the rate of reaction of an enzyme. you could control this by checking the pH of your solutions with a pH probe before the experiment and making sure they all have the same pH. Temperature is another variable which would normally be controlled more precisely, you would use a thermometer to make sure all the solutions are the same temperature, or for even more precision you could heat them all in an water bath to say 30°C to ensure they are at the same temperature. Meiosis Meiosis is a form of cell division which produces gametes or 'sex cells'. Meiosis form 4 haploid daughter cells and each cell is genetically different. In Meiosis a single cell undergoes two divisions, each division goes through the stages of Prophase, Metaphase, Anaphase and Telophase. We demonstrated our knowledge of Meiosis by recreating it with cookies and icing. Prophase 1,2 :
Metaphase 1, 2 :
Anaphase 1,2 :
The very first reptile to use bio-fluoresces has been discovered accidentally by researcher David Gruber of the City University of New York who was studying coral and observing crocodiles off the Solomon islands in the pacific ocean. The turtle in question is a critically endangered Hawksbill Sea Turtle and this is the first recorded time it has shown this behaviour. Scientist are still unsure about the purpose of the bio-fluorescence speculating it may be for mating or some other unknown purpose. Here Is the video taking by the researchers who discovered it. Article source: http://www.iflscience.com/plants-and-animals/first-biofluorescent-turtle-ever-foun Key Enzymes help country kid’s article review:
Research in the past has suggested that kids who grow up in the countryside compared to kids who grow up in urban environments grow a stronger and more capable immune system. This idea of humans having weaker immune system if not subject to bacteria when growing up is called the hygiene hypothesis. This originally was believed to be caused by a person’s contact with endotoxin. Endotoxin is a chemical found on the surface of most common bacteria and humans come into to significant contact with these bacteria and this chemical in the countryside. However it is now being suggested that it is an enzyme called A20 which new born are subjected in the birth canal and researchers believe help train endotoxins to strengthen our immune system and ensure we don’t overreact to harmless microbes. Source: https://www.newscientist.com/article/dn28129-key-enzyme-helps-country-kids-ward-off-allergies-and-asthma/ |
Jack BojanArdingly College Archives
March 2017
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