To determine the water potential of a potato tuber cell using varying salt solution.

Aim To determine the water potential of a potato tuber cell using varying salt solution. Introduction Osmosis is the diffusion of water molecules from a region where it has higher water potential to a region where it has lower water potential through a partially permeable membrane1. As osmosis is a type of diffusion the same things that affect diffusion have an effect on osmosis some of theses things are: * The concentration gradient - the more the difference in molecules on one side of the membrane compared to the other, the greater the number of molecules passing through the membrane and therefore the faster the rate of diffusion2. * The surface area - the larger the area the quicker the rate of diffusion * The size of the diffusing particles - the smaller the particle the quicker the rate and polar molecules diffuse faster than non-polar ones3. * The temperature - the higher the temperature the more kinetic energy the particles have and so the faster they move. From the diagram4 we can see the process of osmosis in a simple expression. On the right side there is pure water, which has the maximum water potential of 0. Water potential is the pressure created by water. As you can see from the diagram the pure water is pushing its way through the semi permeable membrane at a high pressure. This is its water potential. Water potential is measured in kilopascals (kPa)

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Biology CourseworkTo determine if the distribution of flora across Ellerbeck is due to chance. The valley containing Eller beck possesses a huge variety of different species of plant life, particular species are often found in specific places

Biology Coursework To determine if the distribution of flora across Ellerbeck is due to chance. The valley containing Eller beck possesses a huge variety of different species of plant life, particular species are often found in specific places across the valley, to find out why these particular plants grow in the particular places I mean to investigate where different species of plants are located and what the conditions in those particular places are, investigating the effects of several factors on the distribution of these different species across a specific area of the valley. I believe that the varied distribution of the different species investigated is directly related to, and can be explained by the differences in the factors I will be measuring, that certain plants will grow in certain places in the area because they are more suitably adapted, in whatever way to the conditions in that specific place. This is a rough diagram of Ellerbeck. I plan to perform my investigation using two information gathering techniques, after first establishing a straight line across the valley by taking a bearing using a compass from one point at the top of the South side of the valley and following that bearing down the valley, across the beck and up the other side whilst performing both a line transect and an interrupted belt transect. I also plan to perform an interrupted belt

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How the structure of cells is related to their function.

How the structure of cells is related to their function. All living things are made up of cells, whether its plants, humans or even bacteria. There are two different types of cells one is the prokaryotic and the other is the eukaryotic. The name cell was used by an English man who in 1665 use the first microscope and reported seeing what he described looked like the sleeping chambers in the monasteries that were called cells, in a piece of cork.1 The first of the two types is the Prokaryotic cell, the pro meaning before the nucleus as this cell has no true nucleus.2 Prokaryotic cells are surrounded by a cell wall and a cells membrane, and in some ways this makes them similar to a plant cell which is eukaryotic, but they have no nucleus or organelles inside, but they do have flagella's and cilia on the outside. The flagellum is a long whip like tail attached to the end of the prokaryotic cell which helps with its movement. The cilia are small spiked hairs that help to transport fluid in and out of the cell and for protection against harmful substances. They are also found in abundance in the eukaryotic cells in the human trachea where they collect dirt, they either by moving it down into the stomach or push it back up into to the mouth to spit it out.3 One of the most common prokaryotic cells would be bacteria, they are the smallest cellular organism, and each human being

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Artificial Cardiac Pacemakers

Research questions : Why is the constant beating of the heart important? What causes the heart to beat abnormally? What are the implications of having an abnormal heart beat? What is an artificial pacemaker and how does it regulate an abnormal heart beat? How are artificial pacemakers implanted? What are the advantages and disadvantages of using an artificial pacemaker? What are some alternatives used instead of artificial pacemakers? The importance of the heart The heart is an essential organ possessed by every living human. It is vital as it pumps blood rich in oxygen (received from the lungs) to every living cell within the body and pumps deoxygenated blood to the lungs (from the body)1. In the opposite diagram of a human heart, the blue sections represent the transport of deoxygenated blood and the red sections represent the transport of oxygenated blood. The heart is necessary in sustaining the lives of every single human being. This is because without oxygen, cells cannot carry out the process of cellular respiration (the release of energy from glucose). This means that the body cells will have insufficient energy to carry out regular functions needed for sustaining life. Every single cell in the human body is affected by the beating of the heart, as enough oxygen has to be supplied for them to function properly. Without the constant beating of the heart,

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Effects of Surface Area on Catalase Activity in Potato.

Effects of Surface Area on Catalase Activity in Potato Aim To investigate the effect of surface area on the activity of Catalase in potato. Hypothesis I predict that the potato which has been cut into more pieces will have the largest surface area. A larger surface area means that there will be more catalase molecules coming in contact with the reacting substrate, hydrogen peroxide. Enzymes react when particles come into contact with their active sites; if more of the enzyme is exposed (larger surface area) a greater number of active sites will be available to react with the hydrogen peroxide. The surface area of a 5cm tube with a diameter of 2cm equals 37.0 cms² ( 2 rh+2 r² ), but a 5 cm tube cut into five 1cm segments has a surface area of 62.83 cms². Every time another segment is cut from the 5cm tube two more areas have to taken into account, this means each time the 5cm tube is cut into a piece the surface area will increase. As a larger surface area produces a higher rate of reaction, my results should show a higher volume of gas released when using a potato with a larger surface area. Background Knowledge Enzymes are proteins which can be referred to as biological catalysts. Catalysts are molecules which increase the rate of chemical reactions and remain unchanged at the end of the reaction. Enzymes are made up of a chain of amino acids which are

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An investigation into the effect of light intensity on the rate of photosynthesis of Canadian pondweed (Elodea canadensis)

An investigation into the effect of light intensity on the rate of photosynthesis of Canadian pondweed (Elodea canadensis) Planning Scientific knowledge and understanding All green plants need to be able to make their own food. They do this by a process called photosynthesis, which means, "making things with light." Photosynthesis is a series of organic chemical reactions by which green plants produce glucose and oxygen from carbon dioxide and water. It occurs only in the presence of light, and takes place in the chloroplasts of green plant cells. Land plants get carbon dioxide from the air. Water plants get carbon dioxide from water (carbon dioxide in the air dissolved into water). Photosynthesis creates oxygen and sugar. Oxygen is released into the air and used by all animals, including humans, in order to respire. Sugar is used by the plant to respire or store them inside their body. The overall chemical equation for photosynthesis can be expressed as: Plants convert the light energy into stored chemical energy. Photosynthesis is possible because green plants contain an energy-capturing substance called chlorophyll. The plant gets its green colour because chlorophyll is green. Light energy drives photosynthesis. The chlorophyll captures the light energy and uses it to build carbohydrates from simple raw materials (water, carbon dioxide and minerals). The raw

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Myocardial infarction

Case Study 2006 Myocardial Infarction Sharon Thomas Waitakere Hospital Abstract Of This Case Study Have you ever wanted to know what a Myocardial Infarction is and what its all about. Read on and find out through my eyes, about a patient I was caring for - what happened to him in both his body and mind. The following will show what a Myocardial Infarction ( MI ) is, what happens in the patients body and what care is involved by the medical and nursing teams. All of this to ensure my patient would walk out of hospital and again feel like productive member of society that he most certainly was before his cardiac event. Also within the body of this case study will be evidence based articles to support statements made. Congruent to this, will be reflection on how all that transpired with this man affected me and how my nursing practice has developed because of it. This patients health related journey and the anonymous intimacy that took place, came to a happy conclusion for both nurse and patient. Judith Christiansen's Nursing Partnership Model was published in 1990 and was developed in response to the knowledge gaps in the nursing system in New Zealand ( Taylor, 1995 ). This partnership model is a theoretical framework for nursing practice. It has 3 major concepts - these being nursing partnership, the passage and the context. Anonymous Intimacy is one of 3

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Are Blue-Green Algae Bacteria?

ARE BLUE-GREEN ALGAE BACTERIA? Russell Nash Blue-Green Algae, or Cyanophyta, are simple organisms that are believed to be the evolutionary link between bacteria and green plants. Fossils that are over three billion years old have been discovered in sediments and are concluded to be one of the first organisms to release oxygen into the atmosphere. Today, Cyanophyta are abundant throughout the world, found in salt marshes, on tree trunks, in fish tanks etc. Besides the typical bluish-green colour, Cyanophyta can vary from a blackish-green to an orange-yellow. As well as providing an evolutionary link, Blue-Green Algae serve an integral part of our lives with its importance in food supplements as well as its ability to cause economic damage via algal blooming. In this essay I aim to show the similarities and differences between Cyanophyta and bacteria using points of comparison, to answer the question whether Blue-Green Algae can be classed as bacteria. Blue-Green algae are prokaryotic, unlike the rest of the algae family, which can also be said for bacteria. Most of bacteria and Cyanophyta can only be seen through a microscope because they have only one cell and are around 1µm in diameter. In both bacteria and Cyanophyta, the cells have rigid walls. Bacteria have external flagella, which aid movement. Cyanophyta never have flagella. The DNA is able to float freely in a

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GAS EXCHANGE

Gas Exchange Gas exchange supplies oxygen for cellular respiration and disposes of carbon dioxide: an overview • Gas exchange is the uptake of molecular oxygen (O2) from the environment and the discharge of carbon dioxide (CO2) to the environment. • The source of oxygen, the respiratory medium, is air for terrestrial animals and water for aquatic animals. • The atmosphere is about 21% O2 (by volume). • Dissolved oxygen levels in lakes, oceans, and other bodies of water vary considerably, but they are always much less than an equivalent volume of air. • The part of an animal where gases are exchanged with the environment is the respiratory surface. • Movements of CO2 and O2 across the respiratory surface occurs entirely by diffusion. • The rate of diffusion is proportional to the surface area across which diffusion occurs, and inversely proportional to the square of the distance through which molecules must move. • Therefore, respiratory surfaces tend to be thin and have large areas, maximizing the rate of gas exchange. • In addition, the respiratory surface of terrestrial and aquatic animals are moist to maintain the cell membranes and thus gases must first dissolve in water. • Because the respiratory surface must supply O2 and expel CO2 for the entire body, the structure of a respiratory surface depends mainly on the size of the organism,

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How the Mass of Plant Tissue is Affected by a Range of Water Concentrations

How the Mass of Plant Tissue is Affected by a Range of Water Concentrations I will make my investigation fair test by making sure that only the independent variable which is the water concentration changes. There are several control variables which I must ensure I keep the same: * Light * Temperature * Oxygen level in the water * Carbon dioxide level in the water * Size and type of chip I will make sure these remain the same throughout the experiment by: Light: I will carry out the experiment in the same place in the room. Temperature: I will carry out the experiment in the same position in the room. Oxygen level in the water and carbon dioxide level in the water: These are not likely to change much, but I will get the water from the same source. Size and type of chip: I will cut the chips all to the same size and get them from the same source. Prediction I predict that the lower the concentration of water that is in the test tube, the more mass the potato chip will lose. Reasons for Prediction I think that that the end mass will be higher when there is a higher concentration of water because the plant tissue will take in more water. Therefore the more water in the tissue the higher the mass will be. The plant tissue will absorb the water through a process called Osmosis. Osmosis is the movement of water molecules from an area of high concentration to an area

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