Experiment. Hypotheses: The higher the concentration of caffeine the higher the heart rate of the daphnia.
The effect of caffeine concentration on daphnia's heart rate Hypotheses: The higher the concentration of caffeine the higher the heart rate of the daphnia. Biological information: caffeine speeds heart rate, and circulation. Caffeine is a stimulant drug, which causes increased amounts of stimulatory neurotransmitters to be released. It belongs to a Group of chemicals called methylxanthines. Caffeine and similar compounds also inhibit a class of enzymes known as cyclic nucleotide Phosphodiesterases. These enzymes are, in part responsible for degrading a stimulatory signal produced when excitatory neurotransmitters activate different neurons in the central nervous system (CNS). When they are inhibited by caffeine, the stimulatory signal remains active for a longer period of time resulting in a greater sense of alertness (a CNS effect). Independent variable: concentration of caffeine 0- 0.5% Dependant variable: this is the heart rate (BPM) Controls: 0% caffeine to check that water alone does not have an effect on the heart rate compared to pond water. Other fixed/controlled variables: The temperature must always stay constant this means that it must be fixed at room temperature. This can be done by removing the light source from the microscope when not counting because it increases the temperature which leads to an increase in metabolism and therefore an increase in the
What effect does substrate have on respiration in yeast?
What effect does substrate have on respiration in yeast? AIM The aim of this investigation is to find out how the rate of respiration in yeast is affected when different respiratory substrates are used. Five different respiratory substrates will be used and the amount of carbon dioxide produced will be measured for each substrate. The five substrates that will be used are glucose, fructose, maltose, sucrose and lactose. HYPOTHESIS Null hypothesis, H0: There is no significant difference between the amounts of carbon dioxide produced by yeast during respiration, regardless of the respiratory substrate used. Alternate hypothesis, H1: There is a significant difference between the amounts of carbon dioxide produced by yeast during respiration, depending on the respiratory substrate used. PREDICTION Natural habitat of yeast is the skin of fruit, which usually contains fructose and glucose and in some cases sucrose. Yeast is also found on malt so it is familiar with maltose as well. Therefore it will be able to secrete the enzymes needed to break down glucose, fructose, sucrose and maltose. However, lactose is present in milk and other dairy products, where yeast does not live. As a result, it is likely that yeast would not have the enzyme, lactase, needed to break down lactose. The table below shows each substrate, the enzyme needed to hydrolyse this substrate and
Case study - Outbreak of food poisoning at scientific conference.
Case Study "Outbreak of food poisoning at scientific conference" In order to investigate the outbreaks described, the following table (table 1) was presented. The table concentrate at the critical points of the outbreak. The range of onset illness was generated in the table as the incubation period of unknown micro-organism. The duration of the reported symptoms from victims was generated as the duration of illness. The temperature at which the sample was held was generated in the table as environment. Table1. Critical points of the outbreak Outbreak title Outbreak of food poisoning at scientific conference Symptoms Abdominal pain, diarrhoea, fever, nausea, vomiting Incubation period 5-48 hours Duration of illness 3-7 days Likely source of the outbreak Cooked meats (ham, roast beef, chicken) Environment 24°C Examined samples Meats left over Laboratory findings Rod, Gram -ve, facultative anaerobe From the critical points given on the table 1, it could be assumed that the micro-organisms that could be involved in this outbreak were Salmonella enterica (S. enterica), Escherichia coli (E.coli) or Campylobacter jejuni (C. jejuni). These micro-organisms are very common cause of food poisoning and they have very similar properties. They are Gram -ve rods. S. enterica and E. coli are facultative anaerobic micro-organisms and they temperature range is 10 ºC -
Making sense of data - For my Physics coursework I was given the results of an experiment.
Physics coursework - Making sense of data For my Physics coursework I was given the results of an experiment, which involved rolling two differently sized balls (initially 3 however one was marble and did not work with the light gate because it gave 2 readings as it reflected light) one small, silver, with a diameter of 0.006 m and weighing 0.00708 kg and one large, slightly rusty, with a diameter of 0.011 m and weighing 0.01672 kg, down a ramp from different heights and measuring the velocity they travelled at using a light gate, connected to a computer which worked out how long the light beam was broken for. The diagram bellow shows how the experiment was set up: I then had to decided what I was going to use these results for, I decided that I would use them to see if the height the ball is dropped from effects the amount of energy change by working out the difference of potential energy and kinetic energy of the ball. This would mean I would have the amount of energy at the start from calculating potential energy, then the amount of energy at the end of rolling it down the ramp by calculating kinetic energy. I could then find the amount of energy change by subtracting kinetic energy from potential energy. I will calculate the potential and kinetic energy from the mean of 3 tests per experiment. To calculate potential energy I will use the formula: PE = mass (kg) x
How plants have adapted or become acclimated to shade conditons.
Noreen Mc Quaid U5400636 TMA 05 Question 2 HOW PLANTS HAVE ADAPTED OR BECOME ACCLIMATED TO SHADE CONDITIONS. Conditions of shade present low average light intensity for plants, along with a difference in the quality of light (in terms of the numbers of quanta of different wavelengths). Shade light contains more far-red and infra-red quanta and fewer quanta in the range 400 - 680nm. Additionally, light quality and quantity can vary enormously and rapidly due to the occurrence of sunflecks, (a valuable source of light, yet potentially damaging.) Adaptation to shade conditions can be determined genetically or be due to acclimation. Obligate shade plants have evolved genetically to exist in permanent shade and cannot acclimate to long-term levels of high light intensity. However there are plants that show an element of phenotypic plasticity and can acclimate to low (and others to high) light intensities. * Shade plants can absorb and utilize low light intensities more efficiently than sun plants; they have a lower light compensation point and achieve net carbon fixation at lower light fluxes. It is their structural and biochemical characteristics which facilitate these properties. * At a structural level, shade plants have thinner leaves, with a shallow layer of palisade mesophyll and patchy spongy mesophyll containing more air spaces. They have fewer cells per unit area
Daphnia experimentation
The effect of Caffeine on the heart rate Aim: To investigate the effect of caffeine on the heart rate of Daphnia (water fleas). Background Knowledge: Daphnia are tiny water fleas with an average size of less than 3mm. Daphnia are translucent invertebrates (have no backbone) and their outer body is made up of a hard shell which protects the whole body except for the head. Daphnia's are found in ponds, lakes, and calm streams where the temperature is between 21-24°C (68-71°F). Daphnia reproduce rapidly. Up to 13 billion related offspring can occur within 60 days for one Daphnia. In winter the eggs are thick-shelled and thin shelled in the summer. In warmer temperatures the eggs will hatch female, and in colder temperatures the eggs will be male. Daphnia's will be used to experiment the on as although they are tiny in size their heart beat can be examined through a microscope because of their transparency. Caffeine is produced by plants as an insecticide. Cocoa in South America, coffee in Africa and tea in Asia has all been used for hundreds of years to produce "pick me up" drinks containing caffeine. These days, caffeine is used as a flavour enhancer in a wide range of cola and other soft drinks. In addition, it has medicinal uses in aspirin preparation, and is found in weight-loss drugs and as a stimulant in students' exam-time favourites like Pro-plus and Red Bull.
This is an experiment to investigate how temperature effects the respiration rate in maggots.
Investigating the effect of temperature in respiration in maggots. Aim: This is an experiment to investigate how temperature effects the respiration rate in maggots. The formula: The simple formula of respiration is: C6H12O6 + 6O2 6H2O + 6CO2 + ENERGY GLUCOSE + OXYGEN WATER + CARBON + ENERGY DIOXIDE The Collins concise English dictionary explains that respiration is 'the processes by which a living organism...takes in oxygen, distributes and utilizes it in oxidation, and gives off products, esp. carbon dioxide'. Background information: Respiration is the chemical process of releasing energy from organic compounds in living cells. The organic molecules are broken down through a series of steps to act as fuel. The most common organic compound for most cells is glucose however, some cells can break down fatty acids, glycerol, and amino acids in respiration. The energy gained from respiration is used to synthesise ATP (adenosine triphosphate) which is required throughout the body, in order to replenish ATP stores. There are two types of respiration; anaerobic and aerobic. Aerobic respiration occurs when oxygen is freely available, whilst anaerobic respiration occurs when free oxygen is not present, and the process is altered. We will investigate aerobic respiration. There are four main stages of respiration (when breaking down
Design and carry out an experiment to find out the energy content of various foods.
SC1 Investigation Problem For this piece of coursework, I intend to design and carry out an experiment to find out the energy content of various foods. Method For my experiment I have chosen four different foods that I will test for energy content, they are sweetened banana chips, toffee popcorn, original flavour Hula Hoops and salted peanuts. I will use the following apparatus and will set it up as shown: For the experiment all I am going to have three variables, the food that I use, temperature of the water and the weights of the food won't all be equal, everything else will be kept the same, the distance of the candle from the test tube, the amount of water in the test tubes, etc. I will fill the test tube with 25cm3 of water using a measuring beaker. I will do three or four tests of each food as to obtain an accurate result and a good average. For each specimen I will find the starting weight, and the starting temperature of the water in the test tube. For the actual experiment I will start off by attaching the food to a spike and then setting it alight by the use of a candle. I will need to make sure that the candle is not too far nor too close to the test tube so as it won't affect the temperature of the water. As soon as the piece of food is alight I will quickly move it over to under the test tube so that not too much energy is lost during the period of movement
the role of pathology service
WALEED RAHMATI The role of the Pathology Service The Pathology Service is crucial. It provides diagnostic services to family doctors and hospitals department. It is varied discipline, ranging from the study of biochemicals, body tissues and bodily fluids to microbes and antibiotics. The media has given the subject a high profile, which reflects increasing public interest in the area of Pathology within forensics and criminology. I will study: * The role of the Biochemistry, Haematology, Microbiology, Pathology departments and type of tests undertaken in each department. * The stages involved in the processing of specimens and the importance of Health and Safety principles. * The knowledge and skills required by people working in the Biochemistry and Microbiology departments. * And how to conduct a Microbiological analysis and either a Chromatographic or Electrophoresis analysis. My Report will include: * The role of the Biochemistry Department * The types of specimens tested * The nature of the work undertaken in the department, including the common types of tests performed * For example testing for sugars in blood and urine * And estimating blood cholesterol * The principles involved in the use of either thin layer Chromatography or Electrophoresis analysis The role of the Biochemistry Department Introduction The role of the Biochemistry
Monitoring th growth of yeast
Introduction Yeast is a microscopic fungus, of which there are hundreds of species. It is extremely important brewing ingredient because different strains give different beer types their distinctive and characteristic flavors. When a brewery has found an ideal yeast, it will be retained for many years. However, fresh batches are produced regularly from samples kept under special laboratory conditions to prevent the built up of microbiological contamination. (Just as milk can go sour - yeast and bacteria can also contaminate beer). Individual yeast cells are invisible to the naked eye, and are carried in air current. When they grow on a suitable food source (for example fruit, such as grapes and plums) they form 'colonies' of cells. (These can be seen as a fine white powdery film on the skins of the fruit). Yeast can feed on a variety of sugars, converting them into energy in order to grow and multiply. When it first grows, the yeast cells need a supply of oxygen in the same way a animals do when they convert sugar into the carbon dioxide and energy. If animals run out of energy they die. But in the absence of oxygen, yeast obtains its energy from 'anaerobic fermentation' in which sugars are converted to alcohol and carbon dioxide. Most importantly for the brewery, yeast produces a variety of flavoring components (through side reactions), which help give the beer its
