Biology - Most effective way of reducing blood pressure
The Problem - High Blood Pressure has always been the cause of Stokes and CHD (Coronary Heart Disease) leading to a Heart Attack or even CVD (Cardio Vascular Disease). It indeed is the biggest killer in this developed world. High blood pressure directly implicates on the blood vessels, the veins and the arteries. When blood pressure increases, it constantly damages the arteries, whereas arteries already have narrow lumens. When the artery wall gets damaged, by the high blood pressure putting an extra strain on the layer of cells (Endothelium), there are white blood cells moving to the damaged area, and they accumulate cholesterol from the blood. This cholesterol builds a deposit, known as atheroma. This is an inflammatory response. There also are calcium salts and fibrous tissue building up at the site, resulting in a hard swelling called a plaque on the inner wall of the artery. This hardens the artery. Those plaques case the artery to become narrower, which makes it more difficult for the heart to pump blood around the body, in other words, there is a rise in blood pressure plus there now is a positive feedback building up as the process continues. A Blood Clot may also form there and even block the artery completely, minimising the blood supply, containing oxygen, to the heart which can lead to a heart attack and major CHD(s). {Results show that over 7 million people had
The Role of ATP
The Role of ATP Living organisms all need energy to live, for reproduction and for movement. This energy is used in the form of adenosine triphosphate (ATP). It is known as the 'energy currency of living organisms' and can be produced by two methods: . Photosynthesis 2. Chemical Energy Photosynthesis is the absorption of light energy from the sun, which is then transferred into chemical energy. It occurs in plants and results in a useful supply of carbon. Chemical energy is acquired from a 'ready made' source of carbon such as biological materials found in plants and animals, although this energy still originally comes from the sun. ATP * One molecule can contain large amounts of energy which can be used very easily. * ATP is not a storage molecule. * Every cell makes its on ATP, depending on how active it is and its job. * ATP is constantly made and used. 40 kg is made in a 24hr period. Structure Organic base - adenine Pentose sugar - ribose 3 Phosphate groups - inorganic phosphates which are joined by high energy bonds. ATP is a nucleotide and because of its structure, is water soluble and is easily transported around the cell. To release the energy in ATP it is hydrolysed. When water is added, a phosphate group is broken off and energy is released. An enzyme called ATPase catalyses this reaction. When phosphate 1 is removed, a total of 30.6 kJ mol-1
Investigation on the size of Limpets.
Investigation on the size of Limpets Abstract: During my preliminary investigations, I established that sheltered and exposed rocky shores, differed immensely in their size of Limpets. Thus I was inspired to compare the size of Limpets on the sheltered rocky shore, Frenchman's Steps. The background knowledge and preliminary work enabled me conclude the following hypothesis; there will be a statistically significant difference between the size of limpets found on the sheltered rocky shore at two different vertical heights. I decided to look at 3M and 6M above chart datum for my investigation, as looking at the profile graph (appendix) the number of limpets was high at that chart datum. Aim: To determine if there is a difference in the size of limpets at two heights in there Vertical range. Scientific Background Limpets are animals that belong to the family Patellidae, subclass Prosobranchia of the phylum Molluscs. They have a strong, conical shell composed mainly of calcium carbonate, protecting the internal tissue, underneath which is a sucker, also known as the limpet foot, which allows limpets to adhere to rock surfaces, as shown in the photographs. Limpets are usually immobile unless they are foraging and so zonation is less apparent. As can be seen from the pictures above, limpets have a hydrodynamic shape so that resistance to water flow is reduced. This
Global Warming
> Global Warming can be defined as the term used to refer to the fact that the average temperature around the earth is increasing. > Global Warming is caused by many different factors which are mostly as a result of human activities such as the burning of fossil fuels like coal, oil and wood which produce carbon dioxide > The excess Carbon Dioxide that is released in the atmosphere is also contributed by the emission of fumes by factories and motor vehicles. The extra carbon dioxide therefore creates a 'blanket' around the earth resulting in the rapid increase of temperature > Over the past century there has been a marked increase in the concentration of he Greenhouse gases. Greenhouse Gases include carbon dioxide, water vapour, methane, nitrous oxide and ozone. > The Green house gases are also play a huge role in global warming as these gases trap the heat that would otherwise escape to into space. This is called the greenhouse effect > Deforestation is also another cause of global warming because when the excess amount of trees are cut down and not replanted, there becomes an increase in Carbon Dioxide concentration in the atmosphere as there are no trees to use it for respiration. This Carbon dioxide therefore plays a role in global warming as it begins to trap heat on the earth's surface. Consequences of Global Warming > Global warming results in many changes in
How caffeine affects Daphnia heartbeat?
An experiment to determine how caffeine affects the heart rate of Daphnia (water fleas)? Introduction The purpose of this experiment is to determine whether or not caffeine has an affect on the heart rate of Daphnia Hypothesis The Daphnia heart rate will increase with the concentration of caffeine. I based my hypothesis on the fact that humans heart rates increase with caffeine as it acts as a stimulant drug. In the experiment there will be several variables that I need to try and control, the temperature of the water is one of these because if the temperature is higher or lower on the day the results may end up being higher or lower, this would make my results inaccurate. I need to try and limit the human error in the experiment as the daphnia heartbeat is very quick so it will be hard to be completely accurate so we are using the "blind method". We need to use the same microscope throughout testing as others may have different strength lenses. I am also going to keep the species of daphnia the same, as different species may react differently to the caffeine. I will use the same type of caffeine and record the amount of time the daphnia spend in the caffeine before the counting begins, and try to keep this to a similar range. The independent variable I will change is the concentration of caffeine in the water. I am going to be testing 0.1%, and 0.5% caffeine and also
The Development of Antiseptics.
The Development of Antiseptics The problem of infection in surgery The death rate of those having surgery in the mid 17th century was very high, almost half of all those having leg amputations died. This era of surgery was very unusual as although the development of anaesthetics was a massive step forward, the death rate soared. This was because surgeons began to undertake more complicated surgery and spend longer doing it, this meant there was a much greater risk of infection - especially when the instruments and operating theatres were rarely, if ever, cleaned. Infection was very high risk and not only because of the lack on cleanliness. When arteries were being tied off often nothing more than ordinary string and there was little chance of keeping germs from spreading in these theatres because that was what they were - theatres. Many students every day would come to them and watch and learn about surgery, with so many of them so near the operation they couldn't be a good thing - but no body knew this. Semmelweiss' ideas on cleanliness Ignaz Semmelweiss had noticed that there was an unusually high death rate amongst women after childbirth and realised that mothers whose children were delivered by a mid-wife usually survived unlike those who had there offspring delivered by medical students. Semmelweiss thought that if only the students washed their hands before entering
Use of a Redox Indicator to show Dehydrogenase Activity
Use of a Redox Indicator to show Dehydrogenase Activity Hypothesis: As the temperature increases, the time taken for the colour change to occur will decrease. Introduction: Triphenyl tetrazolium chloride (also known as T.T.C) is an example of an artificial hydrogen acceptor. It is a redox indicator which is colourless when oxidised, however when reduced, it produces a red, insoluble precipitate called 'formazans'. T.T.C can therefore be used to investigate the enzyme activity of dehyrogenase enzymes by showing a colour change when they are present. The purpose of this experiment is to see what effect temperature has on the activity of dehydrogenase enzymes within yeast cells. Materials/Apparatus: * Actively respiring yeast suspension. This is prepared by adding 10g of dried yeast to 1dm3 of distilled water, followed by mixing in 50g of glucose. This mixture should be allowed to stand for 24 hours before the experiment takes place. * Tiphenyl tetrazolium chloride is used as a redox indicator to investigate the activity of dehydrogenase enzymes when yeast suspension is exposed to different temperatures. * Distilled water for the preparation of the yeast suspension. * Test tubes to place the mixture of yeast and T.T.C. * Test tube rack to allow the test tubes to stand upright in the water baths. * Incubator to allow enzyme activity to occur at different temperatures *
