Induction of Beta-galactosidase
Induction of Beta-galactosidase Aim: This investigation aims to induce and measure the production of the enzyme beta-galactosidase by E. coli. Scientific Background: Cells only express genes when the protein products they code for are needed, thus conserving energy and resources within the cell. The bacteria Escherichia coli (E. coli) can use different carbohydrates as a food source. If lactose, the disaccharide found in milk, is present in the growth medium it must be broken down into the monosaccharide glucose and galactose before it can be utilized as an energy source in respiration. E. coli has a gene for an enzyme called Beta-galactosidase that breaks down the lactose. The presence of the lactose switches on this gene so the enzyme is produced. Beta galactosidase is the enzyme responsible for the first step in the breakdown of lactose. Since beta-galactosidase is a protein, its structure is determined by the information stored in a DNA molecule. There are several steps required to transfer the information stored in a DNA molecule into the structure of a protein. The first is transcription; transcription involves copying the code in a DNA molecule into a messenger RNA molecule. This process occurs in the nucleus of the cell. Then the translation of this message into the sequence of amino acids in beta galactosidase occurs in the cytoplasm at the ribosome. Once the
Induction of beta-galactosidase
Induction of beta-galactosidase Hypothesis: By adding lactose to the food source of Escherichia Coli, we will introduce the need for ß-galactosidase in the bacteria. The presence of lactose will overcome the forces holding the repressor molecule to the gene which will code for the amino acids which will form the enzyme, therefore the RNA polymerase will be able to bind to the gene and cause the DNA to unwind, allowing mRNA to be produced that codes for the genes. Once the enzyme is produced, it will break down the disaccharide lactose into the monosaccharides glucose and galactose, which are then used in respiration. We will add ONPG to the mixture, which is also catalysed by ß-galactosidase into galactose and GNP, a yellow chemical. The presence of ONP will prove that ß-galactosidase is present in the mixture. Therefore upon adding lactose to a mixture of bacteria and ONPG, ONP will be produced. Aim: We will attempt to find out whether adding lactose in with bacteria will cause the genes which code for beta-galactosidase to be unlocked, ß-galactosidase to be produced and the lactose to be digested into glucose and galactose. Safety Precautions: * Wear gloves and lab coat at all times. * Ensure area used is thoroughly sterilised and there are no stray chairs or bags on the floor and the desk is entirely clear. * Ensure all equipment to be used is sterile. *
Investigation of Some of the Properties of a Pair of Cis-Trans Isomers
Experiment18 Aim To determination the partition coefficient of ethanoic acid between water and butan-2-ol. Procedure . The room temperature was recorded. 2. 15cm3 of the given aqueous ethanoic acid and 15cm3 of butan-2-ol were poured into a 100cm3 separating funnel, using suitable apparatus. The funnel was stoppered and was shook vigorously for 1 to 2 minutes. (The pressure in the funnel was released by occasionally opening the tap.) 3. 10cm3 of each layer was separated approximately. (The fraction near the junction of the two layers was discarded.) 4. 10.0cm3 of the aqueous layer was pipetted into a conical flask and was titrated with 0.1 M sodium hydroxide solution using phenolphthalein. 5. Using another pipette, 10.0 cm3 of the alcohol layer was delivered into a conical flask and was titrated with 0.1 M sodium hydroxide solution. 6. Steps (2) to (5) was repeated with another separating funnel using the following volume: 25cm3 of aqueous ethanoic acid and 15cm3 of butan-2-ol 7. For each experiment, the ratio of the concentration of ethanoic acid in the aqueous layer to that in the butan-2-ol layer was calculated. Result Room temperature: 29? Volume of butan-2-ol: 15 cm3 Volume of 0.2M ethanoic acid / cm3 Volume of 0.1M NaOH titre for aqueous layer / cm3 Volume of 0.1M NaOH titre for alcohol layer / cm3 Partition coefficient K= 5 0.00 2.55 0.796 25
Investigation On Osmosis
Investigation On Osmosis By Alex Rignall Investigation On Osmosis Aim To investigate how much change there is in the mass of a potato chip in varied concentrations of a sucrose solution. Prediction Osmosis: Osmosis is the movement of any of the solutions molecules from a region in which they are highly concentrated to a region in which they are less concentrated. This movement must take place across a cell membrane or a partially permeable membrane, which lets small molecules through and does not let large ones through. I predict that the lower the concentration of sucrose in the solution the more the potato chips will expand. I can say this because I know that there will be more water molecules and therefore osmosis will take place between a lower concentration of water molecules and a higher concentration of water molecules that are separated by a partially permeable membrane such as a the cell membrane of the potato. The sucrose will not cross the partially permeable membrane because the molecules are too big to fit in between the gaps in the membrane. The higher the concentration of sucrose in the solution the more the chips will decrease in mass. I can predict this because from my previous prediction I know that the potato chip will have a higher concentration of water molecules, and therefore the water molecules in the potato chips will move across the partially
Investigation on whether Rubber obeys Hooke's Rule
Investigation on whether Rubber obeys Hooke's Rule Plan Introduction Hooke's Rule states that extension of a material is proportional to the tension force applied to it unless the elastic limit is reached, which is the point at which the material no longer obeys Hooke's Rule. There are only a few materials that obey this rule. In this investigation, we will find out whether rubber obeys Hooke's Rule. We will measure in detail the way in which the extension of a rubber band depends on the tension in the band. This will be done by applying various amounts of weights, as it is a continual variation. Hooke's Rule = F = ke * F = Force in Newtons * k = Spring constant * e = Extension in Centimetres Rubber is a natural polymer which is made up of long chains of molecules which are bent back and forth with weak forces acting between them. As the rubber band is stretched, molecules straighten out and allow the rubber band to become larger. Eventually, as the molecules become fully stretched, the long chains will become parallel to each other and can stretch up to ten times its original length. Extra force will make the rubber band break. If the rubber is not stretched to breaking, once the force is removed the molecules tend to curl back again into their original position because of the attraction and cross-links between adjacent molecules. The return is elastic. Hypothesis I
Investigation into the effect of enzyme concentration of catalysers of sucrose by sucrase.
Investigation into the effect of enzyme concentration of catalysers of sucrose by sucrase Planning Aim: I aim to find out the effect of enzyme concentration on the substrate. I will try to find out how fast the substrate sucrose is broken down using different concentrations of sucrase, to see if there is a link between enzyme concentration and the rate at which the substrate is broken down. An enzyme is made of protein, they are protein molecules which are called a biological catalyst. These molecules speed up chemical reactions and remain unchanged when the reaction is finished. Enzymes have an active site, this is a place where another molecule or molecules can bind to. These molecules are the substrate of the enzyme. The shape of the enzymes active site will allow the substrate to fit onto it. The substrate is held in place by temporary bond that form between the enzyme and the substrate, the bonds form between the R-groups of the enzymes amino acids and the substrate. Only one type of enzyme will work on one type of substrate molecule. This is because the shape of the enzymes active site will only fit the molecule which will fit into its active site. The enzymes catalyse reactions where substrate molecules are split into two or more molecules. In this case Sucrose glucose + Fructose Sucrose is broken down into two molecules by sucrase into glucose and fructose
Investigating the Mechanics of the 100 Metre Sprint.
Investigating the Mechanics of the 100 Metre Sprint In this assignment, I will be investigating the way in which an athlete run a race of 100 metre and also I will look at other different possibilities such as when an athlete accelerate or decelerate during the race. abidzaman, please do not redistribute this dissertation. We work very hard to create this website, and we trust our visitors to respect it for the good of other students. Please, do not circulate this dissertation elsewhere on the internet. Anybody found doing so will be permanently banned. The course is a track of 100 metres in length and I decided that I would not take into account the wind variation in this model because of lack of information. So therefore I assume that there is light wind that will not affect the time.cofd fdr sefdfdw orfd fdk infd fofd fd. Before my research I always thought that sprinters run as fast as they can for the whole distance of the race. But in my researches using the Internet and books, I found out that sprinting is a skilful activity just like football kicking and tennis. Such activity must be practised constantly to retain or improve an athlete's level of ability. Weber refuted abidzaman's structuralism hypothesis. Currently the world record time of the 100-meter race is 9.79 seconds produced by Maurice Greene. I was able to work out his average speed in the following way:
Investigating the effect of Temperature on the Cell Membrane of Beetroot Cells.
Investigating the effect of Temperature on the Cell Membrane of Beetroot Cells. To investigate whether temperature will damage and denature the plasma cell surface membrane of beetroot cells. Background Information. In spite of their many differences in function and appearance, all cells have a surrounding membrane (called the plasma membrane). The purpose of a cell membrane is to selectively control the movement of substances into and out of the cell. The membrane is made of 40% lipids, 0-10% carbohydrate and 50- 60% protein. Lipids tend to liquefy at high temperatures causing ruptures in the plasma membrane. In membranes there are intrinsic proteins that act as 'carriers' and channels that assist with movement of molecules through the membrane and extrinsic proteins that are embedded in the outer phospholipid layer acting as receptors. Proteins inside the cytoplasm are found in the ribosomes, rough endoplasmic reticulum and golgi vesicles. Proteins in plants are more likely to withstand higher temperatures of 50 oC, but once proteins have denatured they are no longer able to carry out there function. The membrane is an extremely thin partially permeable 7.5 (nm) layer. Lipids belong to a group known as triglycerides that are made by the combination of three fatty acid molecules chemically linked to one glycerol molecule. All cells have a surrounding membrane is some
Investigating the effect of temperature on the enzyme amylase.
Investigating the effect of temperature on the enzyme amylase. Prediction. My prediction for this experiment is that as the temperature is increased the time taken for the starch will decrease until a certain point where the time will start to increase. Therefore the rate will increase until a certain point and then will start to decrease. The reason for this being at enzymes work best at a certain temperature from around 35 to 40^0C. The higher the temperature the faster the enzymes will become denatured this is because enzymes are proteins; therefore an increase in temperature will cause an irreversible change in the shape of the molecule, meaning the enzyme is denatured. Moreover, during the five minutes that the amylase enzyme is at the high temperature the faster the enzyme will become denatured. However, the enzymes will not become denatured at a low temperature but enzymes will not work as fast as they would around 35/40^oC. So as the temperature starts to increase the time of the reaction will de crease until a certain point where the time will increase. So in the terms of rate enzyme will work faster until a point where the temperature gets to high and they stop working as fast or all together. Results. Temperature (^0C)^ Time taken for starch to be broken down. (Minutes) First time. Second time (Minutes) Average time (minutes) Rate of
Investigating the effect of temperature on the enzyme amylase.
Biology coursework - Investigating the effect of temperature on the enzyme amylase Introduction Enzymes are vital; they control and catalyse all of the chemical reactions inside living cells. The enzymes speed up reactions, which would not otherwise happen rapidly enough to maintain the essential life processes. Amylase is the enzyme found in our Saliva. It is a catalyst, which works by breaking down substrate into smaller pieces: increasing the surface area, allowing the enzyme to work on the starch quicker and therefore speeding up the reaction. The aim of this experiment is to see how temperature affects the amylase and its ability to effectively break down starch and form maltose. I will be investigating at which temperature the enzyme becomes irreversibly de-natured and at which temperature it becomes inactive. Starch mixed with water on its own reacts very slowly, taking years too react but because we have the enzyme amylase in our saliva the enzymes catalyses the reaction so well that it can break down starch into sugar in minutes or seconds. Variables The variables in the experiment will be the temperature of the saliva and starch solution, the time at which I record the results, the pH of the starch solution and saliva and the quantities of the solutions. The temperature will be the manipulated, Independent variable as this is what I will be changing. The
