How long does it take for the action of the enzyme 'amylase' (a type of carbohydrate) to break down the carbohydrate 'starch'?
Enzyme investigation by Alice Turner How long does it take for the action of the enzyme 'amylase' (a type of carbohydrate) to break down the carbohydrate 'starch'? Factors which may affect results: * Increase in temperature could change time taken for starch molecules to be broken up. * Quantity of enzyme: the more enzyme, the faster the starch will be broken up (the quicker the reaction). * Quantity of starch: the larger the quantity of starch, the more time it will take to be broken up. * The amount of times the procedure is repeated, resulting in fairer, more reliable results. Factor to be investigated: The temperature factor will be investigated. This will indicate whether by increasing the temp, or decreasing the temp, will have any effect on the speed at which the starch is broken down by the enzyme. Prediction It is expected that as the temperature increases, starch molecules will be broken down more quickly. However, the temp may reach a point the enzyme de-natures, or stops working. This can be expected to be above 37.5ºC. (At this temp enzymes and other biological materials may become damaged/ destroyed). The activation site may become wobble-like, and unusable, so stopping starch molecules from being broken up (see diagram). But why does increasing the heat up to 37.5ºC decrease the time taken for starch molecules to be broken down? It is
Beetroot membrane
Why does the colour leak out of cooked beetroot? Aim: The aim of the practical was to use beetroot to examine the effect of the temperature on cell membranes and to relate the effects observed to membrane structure. To function correctly, a cell needs to be able to control transport across the partially cell membrane. The betacyanin pigment (red pigment) is located in the cell vacuole of beetroot cells. If the cell membrane is destroyed (phospholipid bilayer + proteins), leakage (diffusion) of betacyanin is induced. Hypothesis: My hypothesis for this experiment is that more betacyanin pigment will leak out as temperature increases. This is because a higher temperature will cause the pigment molecules to vibrate at a higher frequency and move at a quicker speed, causing them to move out of the cell membrane into the water, making the water appear darker, causing a higher mean colour absorbance reading on the colorimeter. Variables: Independent variable - the temperature of the water in the water bath. Dependent variable - colour change in the water. The increase or decrease of water temperature would have an effect on colour change in the water. Variables which were kept constant were the diameter of the beetroot piece. Risk assessment: * Taking care when using the cork borer and knife when dividing the beetroot sections. * Boiling tubes should be handled with
Observing Mitosis. The purpose of this experiment is to prepare a slide of actively dividing plant tissue and to observe stages of the cell cycle in living tissue.
Observing Mitosis The purpose of this experiment is to prepare a slide of actively dividing plant tissue and to observe stages of the cell cycle in living tissue. We had to consider the duration of mitosis in relation to the whole cell cycle. First of all got some hydrochloric acid and put it into a water bath at 60°C. Then we cut off some root tips from garlic, we used the tips because it's where mitosis still takes place - the meristem. We put these roots into some acetic alcohol which is a fixative, so it stops and helps preserve the cells. Then we removed them and put them in ice cold water and then dried them on filter paper. After this we put the root tips in the pre-heated hydrochloric acid, this will dissolve the calcium pectate but leave the cell walls unharmed. So it breaks up tissue without damaging the cell. After cooling down again and drying, we put the root tips onto a clean microscope slide and cut off the tip of it. We had to make sure it was the meristem and not other differentiated root tissue. Then we macerated the root tip, this breaks up all the cells and makes them one layer. If not sufficiently macerated the layer may not be thin enough to observe cell nuclei. After this we added a small drop of acetic orcein stain so that we could see the cells under the microscope. We then added a cover slip over the cells, and blotted firmly to get rid of
To investigate the effect of Diastase on Starch
To investigate the effect of Diastase on Starch Aim The aim of this experiment was to investigate the breakdown of starch by diastase. There where a lot of different variables that could be changed. The possible variables that could be changed were: . Temperature The temperature of the water that the reaction was carried out in could be changed. 2. Concentration of Starch The concentration of the starch that will be used can be changed. 3. Concentration of Diastase The concentration of the diastase that will be used can be changed. 4. pH of Solutions The pH of both the solutions could be altered. 5. Volume of Starch The amount of starch that is used could be changed. 6. Volume of Diastase The amount of diastase that is used could be changed. 7. Amount of Iodine used The amount of iodine that is used could be changed. 8. Agitation The amount of agitation the test-tube is subjected to after the solutions are mixed. The variable that I am going to change is temperature. This is because it is one of the easiest to control and is almost guaranteed to get accurate results. Research in to Enzymes Enzymes are biological catalysts made up from protein that control vital biological processes. As we know catalysts are substances that speed up a rate of a reaction without itself being used up. An enzyme has an active site, which has a unique shape into which only
The Function and Structure of Lipids in Living Organisms
The Function and Structure of Lipids in Living Organisms Lipids are a group of organic compounds that are fatty acids and include Oils, Fats, Waxes and Steroids. They are also all insoluble in water because they are non-polar but are soluble in solvents, which is why solvents are often used in home cleaning products like oven cleaners and drain cleaners to remove build-up's of fats and oils. Also lipids like wax can be very useful and vital for many creatures such as bird and semi-aquatic mammals which use them to make their feathers fur waterproof. Similarly humans use keratin in the epidermis and oil produced by the sebaceous glands help to make their skin waterproof(1). The structure of lipids Lipids similar to carbohydrates contain carbon, oxygen and hydrogen, but in lipids the proportion of oxygen is a lot lower than carbohydrates. Also lipids are insoluble in water because they are non-polar which means that the positive and negative charges cancel out each other so it doesn't have a positive or negative charge but they are soluble in organic solvents such as ethane and methane because they are also non-polar. Fatty acids can be saturated or unsaturated depending on their carbon bonding and can be told apart easily because of their state at room temperature, ether solid or liquid. Saturated fatty acids are made up of hydrogen, oxygen and carbon, the carbon in the
Beetroot practical
Why does the colour leak out of cooked beetroot? The aim of this experiment is to investigate the effect of temperature on membrane structure. I predict that as the temperature of the water in which the beetroot is placed increases, the amount of pigment leaked will increase. My prediction is based on the concept that cell membrane will breakdown as the temperature rises. Apparatus * Corer * White tile * A Beetroot * Automatic Water Bath * Segregated knife * A thermometer * Stopwatch Method: * First I took the white tile and the corer. Then collected a cylinder of beetroot by pushing the corer into the beetroot and withdrawing it. The cylinder remains inside the corer. * I collected 2 cylinders, and cut them into 8 pieces of 1 cm with a segregated knife. Because the beetroot has been cut some of the cell membranes had been broken, which means some pigments leaked out. * I left the beetroot pieces in a beaker of distilled water for one night. * Next day I placed the beetroot pieces into tubes of 5 cm of distilled water and placed them into different baths with different temperatures between 0-70. * After 30 minutes I collected 2cm3 fluid from each water baht. * The fluid in each of the test tubes was analysed using a colorimeter The variables kept constant * ?The same diameter corer is used so to keep the surface area of each beetroot piece the same
Membrane permeability in beetroot cells.
Membrane Permeability in Beetroot cells Beet root cells contains a red pigment, which is found in the cell vacuole. The vacuole has a membrane in which its function is mainly to prevent the betacyanins from leaving the cell. Leakage of these betacyanins into the external solution can be used as an indication of membrance pereambility changes. As part of my experiment, my aim is to see if temperature affects the membrane by witnessing the amount of betacynanins that leaks from the beetroot cells. The cell membrane covers the outside of a cell and consists of a double layered sheet of lipid molecules interspered with proteins. It seperates the cell from the external environment, gives phyisical protection and allows the import and export of selected chemicals. Aim: I will commence the experiment by placing beetroots in a test tube of deionised water, I will use a range of temperatures in which I will place the beetroot cell to see the damage later on. After placing them in series of test tubes of deionised water for 30 minutes. I will pour out each solution into a cuvette and place it in a colorimeter, This will enable me to witness variations in my experiment. Prediction: My prediction to this investigation is that, as the tempertaure of the deionised water increases, so will the membrane permeability of the beetroot cell. In doing so, this will cause the beetroot
Investigating the Effect of Ethanol Concentration on the Rate of Respiration in Yeast.
Investigating the Effect of Ethanol Concentration on the Rate of Respiration in Yeast Respiration is the process by which the energy in food molecules is made available for an organism to do biological work. Respiration produces ATP, which is the form of energy, made by most organisms, and they use it for their survival. Yeast cell, along with all other cells respire, and I am going to investigate the effect on the rate of respiration when I add various concentrations of alcohol to it. Scientific Theory: There are many factors that can affect the rate of respiration in a yeast cell. In my experiment, I am going to develop this with how an alcohol affects the rate at different concentrations. The equation for aerobic respiration is C6H12O6 + 6O2 6CO2 + 6H2O + Energy ... Is the standard equation before the alcohol is added. As the alcohol is the factor I am assessing, then the concentrations of the yeast solution, and how much sugar I am adding, need to be determined before I can add the different volumes of alcohol, in this case Ethanol. I am going to do this by carrying out preliminary experiments. Glucose concentration is an important part in the reaction as this helps the reaction to get started. If too much glucose is added, then this has an osmotic effect on the yeast cell, pulling all the water out of them and preventing the from respiring. This
I am going to investigate the ability of Pepsin on Gelatin. I aim to investigate the effect of temperature on the rate of action of Pepsin on Gelatin.
Investigation into the action of Pepsin I am going to investigate the ability of Pepsin on Gelatin. I aim to investigate the effect of temperature on the rate of action of Pepsin on Gelatin. Apparatus List Black and white filmstrip, pepsin solution, water baths, 400 cm³ measuring cylinder, small tubes, 200 cm³ beakers, stopwatch, 0?c -100?c thermometer, scissors, tweezers, syringes. Preliminary Work The student spent time experimenting with different quantities of pepsin and other controlled factors to try to find out which quantities would work the best. It decided that a 2cm by 2cm black and white filmstrip should be used. This is because it fits inside the specimen tube, it stays still in the specimen tube and it easy to see. In the preliminary experiment a 1cm by 1cm filmstrip was used and it was difficult to see. I decided to use 14ml of pepsin in each test tube because it is just enough to completely submerge the filmstrip. A 2% solution of pepsin has been proven to be the most effective in previous experiments. The volume of the pepsin was chosen to be 20ml. Variables * The volume of pepsin that is used * The amount of filmstrip that is used * Temperature of the pepsin * The concentration of the pepsin solution that is used * The apparatus that is used. * The method that is used. * Quality of film * pH of pepsin The variable will be temperature. This
Factors effecting enzyme activity
Biology Coursework Factors effecting enzyme activity Aim: To investigate the effect of temperature on the rate of catalase activity. Enzymes are proteins that act as catalysts, which are made in the cells. A catalyst is a chemical substance that speeds up a reaction but does not get used up in the process. Enzymes can be used over and over. There are two types of enzyme reactivity, these are called anabolic and catabolic reactions. An anabolic reaction is where large molecules are built up from smaller molecule. A catabolic reaction is where reactions split large molecules into smaller ones. Enzymes work by a method called the lock and key method: Basically it works by the enzyme meeting the substrate and they both fit together well to make an enzyme-substrate complex. This works well because enzymes have a definite three dimensional shapes which is complementary to the shape of the substrate. In the enzyme-substrate complex, the substrate attaches to an area on the enzymes known as the active site. The enzyme is then free to react again with any available substrate. Catalase can be found, not just in humans but in potatoes, apples and the liver. During my preliminary work, I will be investigating which of these gives off the most oxygen. The one which gives off the most oxygen will be the catalase that I use during my experiments. This way it will give me the best
