Escherichia coli and antibiotic resistanceIntroduction:Escherichia coli, short E. coli is an important bacteria that are
Escherichia coli and antibiotic resistance Introduction: Escherichia coli, short E. coli is an important bacteria that are found in the lower part of intestines of warm blooded animals, including human. People's feces for a day usually contain about 100 million or 10 trillion individuals of E. coli. E. coli is a major component of a bacterial system that helps to digest food particles. E. coli also has commercial uses. For instance, is used as an organic indicator for the sewage treatment to indicate the level of the concentration of poop pollutions in the water. However, uncontrolled growth of E. coli bacteria or the allocation of E. coli to other parts of the human body can be dangerous or even fatal. E. coli is also used in many laboratory experiments because they are cheap to acquire and easy to culture. When people are referring to bacteria that are resistant against penicillin, for instance penicillin resistant E. coli, these people are referring specifically to the ability of this bacteria population to produce an enzyme called penincillinase. Penincillinase is a general term describing a wide variety of enzymes that are capable of deterring penicillin invasion. A common type of penincillinase is plasmid-mediated extended-spectrum b-lactamases (ESbl) (bacteria can transfer genetic material through replication or plasmid). Plasmid-mediated means that the enzyme is
Taxonomy is the branch of biology that deals with the identification and naming of living organisms
Mr. Miller Biology 401A Biology Essay BEGÜM COGAL A species is a genetically distinct group of organisms, which can interbreed and produce fertile, viable offsprings. External similarity is the common basis for identifying individuals as being members of the same species. Yet a bulldog, a terrier, and a golden retriever are very different in appearance, but they are all dogs because they can interbreed. People can also interbreed with one another, and so can cats, but people cannot interbreed with dogs or cats, nor can these with each other. This shows that individuals of a species are able to interbreed with one another but not with members of other species. Even if they could interbreed with members of other species they would not be able to produce fertile offsprings. For example, when horses and donkeys mate, they produce mules. However, these mules are infertile. They are unable to breed at all and bear offsprings of their own. Taxonomy is the branch of biology that deals with the identification and naming of living organisms. The Swedish biologist, Carolus Linnaeus (1707 - 1778) established a simple system for classifying and naming organisms. He developed a hierarchy, or in other words a ranking system for classifying organisms, that is the basis for modern taxonomy. Linnaeu's classification hierarchy included five levels: kingdom, class, order, genus, and
Osmosis in Potatoes Lab. At which concentration of sucrose in water (% mass by sucrose) will the potato core be isotonic, meaning that there is no movement of water in or out of the potato core?
Osmosis in Potatoes Date of Experiment: Feb. 4, 2009- Feb. 6, 2009 Research Question: At which concentration of sucrose in water (% mass by sucrose) will the potato core be isotonic, meaning that there is no movement of water in or out of the potato core? Hypothesis: If the percent mass by sucrose of the solution is in between 10 and 30 percent, then the solution would be isotonic, meaning that no osmosis occurs between the potato and the solution. I assume this because the percent change before and during 10 percent indicates water moving into the potato (hypotonic), and the percent change during and after 30 percent mass by sucrose indicates that water is moving out of the potato (hypertonic). Variables: > Independent: o Percent of mass by Sucrose in each solution > Dependent: o Percent change in mass of potato cores > Control: o Length of time each core stayed in solution o Size of each potato core o Amount of solution in each test tube o Temperature of solution and surrounding area o Potato from which the cores come from Materials: o Potato Electronic Scale o Cork Borer 6 Test Tubes o Tweezers Beaker o Water with different amounts of Sucrose (0%-50% by mass) Procedure: . Fill each test tube with __ mL of only one solution of water and sucrose (0%- 50% by mass). 2. Label each test tube with the solution it is holding (% of mass by sucrose in
Biology Revision notes - Human Biology
Blood Pressure * Each time your heart contracts, it pumps blood into out arteries. * The blood needs to be under pressure so that it reaches all the parts of the body. A pulse - this is the recoiling of the arteries. Arteries are elasticised so that when blood is pumped, they expand and then contract. * The fitter you are, the lower your heart rate is because your heart is more efficient. * Pressure is created due to the blood pressing against the arteries and this is known as blood pressure. Blood pressure appears as a fraction and is measures in mmHg: Systolic: the heart contracts and pumps - The highest pressure on the arteries. Diastolic: the heart is relaxes and doesn't pump - The lowest pressure on the arteries. (mmHg - millimetres/mercury) Blood pressure is affected by: * Weight - being overweight increases the risk of high blood pressure * Exercise - strengthens heart muscles and keeps the heart fit * Diet - avoid salty and fatty foods * Temperature * Alcohol * Stress * Smoking - narrows blood vessels * Inheritance * Age - blood pressure increases with age * Underlying diseases High Blood Pressure Can cause: * An artery to burst * A stroke * A heart attack * Death High blood pressure means that the blood is pushing too hard against the artery walls. This damages the artery lining and allows fat and calcium to build up and form a plaque.
n this essay I will analysing what makes us happy and be going into vast depths as to what factors affect happiness and how certain chemicals, neurotransmitters and endorphins in the brain affects this procedure.What makes us happy
What Makes Us Happy By John Smith In this essay I will analysing what makes us happy and be going into vast depths as to what factors affect happiness and how certain chemicals, neurotransmitters and endorphins in the brain affects this procedure. Firstly I will be assessing the key question; what is happiness? We already know happiness has many forms, but what we will be going into, is what defines happiness and how do we find this out? In order to be happy, scientists have put the ideas of many generations of people together and have come with a theory that makes us happy. [1]To begin with we must have a goal, whereby we have a point of destination we consider worthy for our effort, this goal can be really small or really big. Secondly, we also need to live our life with enthusiasm, optimism and honesty. Only after reaching all these areas, can we become happy people. For reaching the superior more advanced forms of happiness, such as achieving satisfaction and contentment, we require taking paths leading to a meaningful life; a life where through having goals, we will find fulfilment. Generally the rule is that; the smaller the goal, the shorter the time of happiness, for example; buying a new car or a new home can give us a quick feeling of enjoyment but at the same time can quickly wear off, compared with these next factors. Health, family and friends,
What affects osmosis
Elena Uteva Investigating the factors that affect osmosis in a model potato cell Introduction In the following investigation, I shall explore and come to a conclusion on the effect of varying the concentration of the surrounding sucrose solution on a model potato cell. Osmosis is defined as the passage of water molecules through a selectively permeable membrane from a region of high water concentration to a region of low water concentration until a state of equilibrium is reached. The selectively permeable membrane is permeable to the solvent and not to the solute and therefore results in a pressure gradient across the membrane. My hypothesis regarding this investigation is that an increase in the concentration of the sucrose solution will decrease the mass of the potato chip. This is because a higher solute concentration will result in lower water concentration, since by increasing the solute concentration there would be more solute molecules in a given volume and hence a lower amount of water molecules. Therefore by placing the model potato cell into a hypertonic solution, the water concentration will be higher in the cell in relation to the solution (www.tvdsb.on.ca/westmin/science/sbi3a1/Cells/ Osmosis.htm) and consequently will result in the water molecules diffusing out of the cell and the cell loosing mass. Conversely, by decreasing the
Plan: The effect of the end product, phosphate, on the enzyme phosphatase
The effect of the end product, phosphate, on the enzyme phosphatase . Plan Phosphatase enzymes release phosphates from a variety of substrates for synthesis of nucleotides, phospholipids, etc. They are found in both plant and animal tissues and can be classified as acid or alkaline depending on their optimum pH. In this experiment an acid phosphatase from potato was used. Hypothesis Since phosphate is a product of phosphatase activity, it may act as an end product inhibitor of the phosphatase enzyme, therefore slowing down the enzyme-catalyzed reaction. Background knowledge Enzymes are biological catalysts which speed up the metabolic reaction inside the cells. Enzymes are proteins and therefore can function because of their specific 3D shape. The active site is part of the molecule which allows the substrate to enter and form enzyme-substrate complex. If the shape of the active site changed, the substrate will not fit in, therefore the enzyme cannot function properly. The activity of enzyme is not only affected by temperature, pH, but also by enzyme inhibitors. These are the substances which can reduce the activity of enzymes. There are two types of enzyme inhibitors which refer to competitive and non-competitive inhibitor. Competitive inhibitor is a molecule which has a similar shape to the substrate, competing with the substrate for the active site of the enzyme and
Biology lab - transpiration
AP Biology Lab 9: Transpiration Introduction Most of the water a plant absorbs is not used for a plant's daily functioning. It is instead lost through transpiration, the evaporation of water through the leaf surface and stomata, and through guttation, which is the loss of water from the vascular tissues in the margins of leaves. There are three levels of transport in plants: uptake and release of water and solutes by individual cells, short distance cell to cell transport at tissue and organ levels, and long distance transport of sap by xylem and phloem at the whole plant level. The transport of water is controlled by water potential. Water will always move from an area of high water potential to an area with low water potential. This water potential is affected by pressure, gravity, and solute concentration. Water moves into the plant through osmosis and creates a hydrostatic root pressure that forces the water upward for a short distance, however, the main force in moving water is the upward pull due to transpiration. This pull is increased by water's natural properties such as adhesion and cohesion. Transpiration decreases the water potential in the stele causing water to move in and pull upward into the leaves and other areas of low water potential. Pressure begins to build in the leaves, so to prevent downward movement, guttation occurs. Guttation occurs through leaf
Embryo Screening. The embryo screening, also referred as PGD (preimplantation genetic diagnosis), is a procedure tested on an embryo to identify any unwanted diseases that is found in the genes of the embryo.
Embryo Screening Settling down and starting a family is what many couples have in mind. It's a life changing decision the many indivisual choose to endure, however, obstacles and complications have delayed couples from fulfilling their goal. Leaving the chances of pregnancy aside, couples try to prevent many issues that occur with their newborns - infectious and complicated diseases, deformities and abnormalities. In many cultures and races, it is customary, or even the norm, to marry close relatives. This scientifically has been proven to increase the chances of having your offspring inherit the diseases that have been in the past generations, such as diabetes, cancer, anemia and leukemia. [8] One type of solution that has been discovered is embryo screening and human genetic engineering. The embryo screening, also referred as PGD (preimplantation genetic diagnosis), is a procedure tested on an embryo to identify any unwanted diseases that is found in the genes of the embryo. This then enables the couples to be aware of the problems that they might be facing if they do get pregnant, and leaving their embryo untouched. After enlightening couples about the genetic diseases found in the genes, they have to whether to go through the PGD and modify the genes to contract the ones that contain the genetic information about the disease, abnormality, or deformity. "PGD involves
Is the MMR vaccination safe?
Contents 2 Introduction 3 How does MMR give immunity? 4 How was MMR tested for safety? 5 What about the side effects? 6 Is there a link to autism and bowel disease? 7 Are separate vaccinations a better alternative? 0 What about mercury in vaccinations? 2 Are homeopathic substitutes an alternative? 1 Conclusion 2 Bibliography and References 3 Introduction MMR is a combined, live, attenuated vaccination which is given to children firstly at 13 months and then again as a booster at 3 years 4 months. It provides immunity against three diseases caused by viruses: measles, mumps and rubella. The diseases are all extremely unpleasant and can lead to serious complications (26). * Measles is an extremely infectious virus that usually causes high-fever, a rash and generally feeling unwell and will usually last for around five days in children, however sometimes longer in adults. One in every fifteen children will have serious complications, such as chest infections, fits and encephalitis (the swelling of the brain which can lead to brain damage). In extreme cases it can even be fatal. In 1987, the year before the MMR vaccination was brought into the UK 86,000 children caught measles and 16 died (1). * Mumps is another virus which also causes a fever, but also headaches, swollen glands in the face, neck and jaw and it can even result in permanent deafness and
