Beetroot Practical Write up
Biology Coursework Beetroot Hypothesis: To investigate the effect of different concentrations of ethanol on the permeability of beetroot cell membranes. Prediction: By exposing a membrane to a solvent, ethanol, it will affect its permeability. Therefore higher the concentration of the solvent, the more permeable the membrane will be. But by increasing the concentrations of the ethanol beyond a certain point it may have no affect on the cell membrane because the ethanol would have broken down the cell membrane completely. This is because of the effect of ethanol on the lipids in the membrane. Also, more dye would be present as the lipids are essential to the structure of the cell membrane as they control the substances that enter and leave the cell. Ethanol could also destroy some the proteins or denature the structure because protein has a tertiary structure. The ethanol would destroy the hydrogen bonds that hold the protein structure. Therefore, with the lipids and proteins destroyed in the cell membrane, the pigment is allowed to escape from the cell due to there being no cell membrane holding substances in the cell. Scientific Knowledge: Transfer across cell membrane structure: There are many ways that ions and molecules are transported across the cell membrane. By this, the cell must acquire the ions and molecules they need from their surrounding
An Investigation into the Water Potential Of Root Vegetables.
An Investigation into the Water Potential Of Root Vegetables. The aim of this investigation is to find the water potential of two root vegetables and to evaluate any differences that are found. Root vegetables take in the water they need through a process known as osmosis. Water moves from an area of high water potential to an area of low water potential through a partially permeable membrane. The water potential of root vegetables depends on the concentration of solutes within their cells. Starch is not soluble so the starch content of the vegetables will not affect the water potential. Sucrose however is soluble. In the investigation I will find the isotonic solution for each vegetable based on the principle that when the vegetable is in a hypertonic solution it will lose water (and become plasmolysed) and therefore lose mass and that when the vegetable is in a hypotonic solution it will gain water (and become turgid) and gain mass. By calculating the percentage change in each vegetable piece I will be able to find the concentration of sucrose solution at which the vegetable will gain no mass. Once the isotonic solution is found for each vegetable, its water potential can be found by using a reference graph, which shows the water potential for different concentrations of sucrose. The two vegetables I will use will be a potato and a swede. Swedes are considered a sweet
Effect of enzyme concentration on rate of reaction
Title : Effect of enzyme concentration on rate of reaction Objective : To investigate the effect of enzyme concentration on rate of reaction Introduction : Enzyme A catalyst is a substance which speeds up the rate of reaction without changing the product and is left unchanged at the end of the reaction1. An enzyme is a biological catalyst that catalyses metabolic reactions in your body such as digestion and respiration. At any time, many reactions are occurring simultaneously in our bodies. There are two types of reaction that is the anabolic reaction and the catabolic reaction. An anabolic reaction is a reaction that results in the formation of a substance from two or more substrate molecules while a catabolic reaction is a reaction that involves the breakdown of a substance into two or more product molecules. A combination of biochemical reactions like these are known as metabolism.. Enzyme action can be intracellular that is within cells or extracellular that is outside cells. Extracellular enzymes such as digestive enzymes are effective in the digestive tract while intracellular enzymes are found in the cytoplasm, nucleus, mitochondria and chloroplasts in cells.2 Enzymes are complex proteins which have are made of several polypeptide chains joined together. Enzymes have a tertiary or quaternary structure which is held together by bonds such as hydrogen bonds,
Biology Coursework - Osmosis - To Investigate concentration of sucrose solution is isotonic to potato cell sap.
Biology Coursework - Osmosis Planning Aim: To investigate what concentration of sucrose solution is isotonic to potato cell sap. Apparatus: 0M sucrose (aq) (distilled water) 2M sucrose (aq) Potato Chip cutter Knife Boiling tubes Measuring cylinder (25cm3) Vernier callipers (to nearest 0.1mm) Balance (to nearest 0.01gram) Safety: I will ensure safety around the lab by: wearing safety goggles, laying paper towels, removing baggage from walking space, push stools under the bench, stand up, walk carefully and slowly - don't rush and handle equipment and apparatus carefully. Preliminary Experiment: I did a small experiment before doing the real one so I could find a suitable range to base my investigation round. I used 3 chips in 3 boiling tubes, each containing 20cm3 of: 0M sucrose, 0.5M sucrose and 1M sucrose. Moles of Sucrose /M Original Mass /g Mass after 3 hours /g Up/Down in mass 0M 8.02 9.94 Up 0.5M 8.18 7.83 Down M 8.83 7.20 Down As you can see from my preliminary results, I should investigate between 0M sucrose and 0.5M sucrose as a suitable range. I predicted that the isotonic concentration lies between 0.35M and 0.4M. Method: I will cut 5 chips with no skin on them and have them approximately the same length, width, breadth and mass (using the balance and Vernier callipers for extra accuracy), then I will dry off the sap completely. I will
Investigate a factor which can affect the process of osmosis in a living plant tissue
Meetal Odedra 11V Biology coursework Investigate a factor which can affect the process of osmosis in a living plant tissue Planning For this coursework investigation I will be investigating factors that affect the process of osmosis in a living plant cell, but mainly focusing on one factor I have chosen. In order to do so, I have conducted some background research on osmosis to help me understand the investigation in hand. Background Scientific Research (Using D.G. Mackean's GCSE Biology textbook) Osmosis is defined as the movement of water molecules from a high concentration of water (potential) to a lower concentration of water (potential) down a concentration gradient, through a partially permeable membrane. When a substance such as sugar dissolves in water, it reduces the concentration of the water molecules because the sugar molecules attract some of the water molecules and stop them moving freely. Osmosis can be explained with the help of the diagram below: The diagram shows that the sugar molecules on the right have attracted half of the water molecules. There are now more free water molecules on the left than on the right so water molecules will diffuse more rapidly from left to right across the partially permeable membrane, than from right to left. This is because the net movement of the water molecules move from the high concentration of water
Investigation to determine the effect of different brands of mouthwashes on microbes
Biology Investigation Coursework Investigation to determine the effect of different brands of mouthwashes on microbes Results For Pilot with Microccus Liteus When analysing my results, I thought it would be easier to draw an accurate line around the area of the mouthwash sample so that I would be able to measure the zone of clearance accurately using the digital callipers. The area that has been cleared of microbes is the value that I have recorded in the table below. I have used the digital callipers with a reading of 3 s.f to maintain accurate results throughout the experiment. Result No. Mouthwash A Mouthwash B Mouthwash C Mouthwash D 6.10 mm 4.13 mm 5.20 mm .89 mm 2 7.05 mm 4.69 mm 4.83 mm 2.06 mm 3 6.95 mm 4.93 mm 5.73 mm .88 mm 4 6.29 mm 4.79 mm 5.81 mm .90 mm 5 6.45 mm 4.42 mm 5.39 mm 2.64 mm Average 6.5975 mm 4.635 mm 5.3925 mm 2.074 mm Order of Zone of Clearance of Microbial Decay (Highest to Lowest) . Mouthwash A - Colgate Plax 2. Mouthwash C - Listerine 3. Mouthwash B - Dentyl Active 4. Mouthwash D - Superdrug Figures 1 to 3 show photographs of some of the results I collected from the pilot investigation. You can clearly see that different brands of mouthwash had different effects on the microbes as some destroyed them more than others and this is shown by a ring of clearance around each sample of mouthwash on the filter
Are mobile phones a health risk?
Abstract In this report I aim to determine whether or not mobile phones pose a risk to our health. I will explain how mobile phone electromagnetic radiation can be perceived as dangerous, with reference to the EM spectrum. I will cite scientific sources of evidence which support both sides of the dispute, and will come to a reasoned conclusion as to how likely it is that mobile phones are a health risk. I will also evaluate the credibility of the sources used to support my conclusions, and list all the sources used throughout in a detailed bibliography. Introduction Mobile phones are becoming increasingly popular in today's world; with around 80 million handsets in Britain, there are now more mobiles than people [1]. They've become an essential part of our existence, in business, in our daily lives and in keeping in touch with our loved ones - however, there is growing concern that this technology is causing serious health problems throughout the population, such as lasting brain damage and cancer. The Media consistently tends to portray mobile phones negatively, fuelling the public's fears and misgivings: this study aims to determine from the scientific evidence whether or not mobile phones present a risk to our health. Main Points How might Mobile Phones be Hazardous to our Health? After studying numerous publications, I have found that if there are concerns about how
Investigate the Properties of Ionic and Covalent substances
Title: To Investigate the Properties of Ionic and Covalent substances Introduction: Certain properties of compounds, such as polar and non- polar solvents, melting point and conductivity of electricity, can be used to distinguish between Ionic and Covalent substances. Aim: To determine whether common laboratory substances are ionic or covalent in nature. Apparatus/Materials: Sodium Chloride Test Tubes Sucrose Glass Rods Naphthalene Beaker (2- 100cm3) Copper (II) Sulfate Battery Calcium Carbonate Connecting wires Calcium Oxide Electrodes Spatulas Bunsen burner Tongs Method(1): Heating Substances Approximately two spatulas of sodium chloride was placed into a test tube and its contents were gently heated at first then heated strongly until no further change occurred. This was repeated with the other salts. Method(2): Solubility of Substances Two spatulas fall of sodium chloride was poured into breakers 1 with water and oe with ethanol. Solution was mixed and was held for conductivity test same was done for other salts. Method(3): Conductivity Electrodes were connected to connecting wires and
Proteins have many functions in the human body and these include transport, catalysis, protection, storage, sensitivity, structure and co-ordination.
Proteins Introduction Protein accounts for about three-fourths of the dry matter in human tissues other than fat and bone. It is a major structural component of hair, skin, nails, connective tissues, and body organs. It is required for practically every essential function in the body. Proteins are made from the following elements; carbon, hydrogen, oxygen, nitrogen and often sulphur and phosphorus. Proteins cannot be stored except in eggs and seeds and they form the body's main structural elements and are found in every cell and tissue. The human body uses proteins for growth and to build and repair bones, muscles, tissue, skin, internal organs and blood. Hormones, antibodies and the enzymes that regulate the body's chemical reactions are all made of protein. Without the right proteins, blood won't clot properly and cuts won't heal and if carbohydrates and fat can't meet your energy needs, proteins can be broken down and used as a source of emergency energy. So this makes protein very crucial for your health. Each protein is a large complex molecule; these molecules are made up of a string of amino acids. There are 20 different amino acids that occur naturally to form proteins and they all have the same basic structure. The 20 amino acids the body needs can be linked in thousands of different ways to form thousands of different proteins, each with a unique function in the
Mr Chips: Investigation to find an isotonic solution for potatoes
Mr Chips: Investigation to find an isotonic solution for potatoes Introduction Investigation aimed to find out the amount of grams of salt solute needed to create an isotonic solution to prevent osmosis in fresh cut potato chips. Osmosis is the movement of water molecules through a selectively-permeable membrane down a water potential gradient. More specifically, it is the movement of water across a selectively permeable membrane from an area of high water potential (low solute concentration) to an area of low water potential (high solute concentration). The water molecules will continue to move through the semi-permeable membrane until both sides have reached a state of equilibrium. Isotonic solution is a solution in which its solute concentration is the same as the solute concentration of another solution with which it is compared In plant cells when water moves into the vacuole it increases in size and pushes the cell membrane against the cell wall, this causes the cellulose cell wall to stretch slightly and when it can stretch no further it becomes taut and firm. The pressure inside the cell rises and eventually the internal pressure of the cell is so high that no more water can enter the cell. This liquid or hydrostatic pressure works against osmosis. At this point the cell wall prevents the cell from bursting and is said to be fully turgid. Turgidity is very
