Heart Disease
Heart Disease Essay written by Samuel INTRODUCTION In today's society, people are gaining medical knowledge at quite a fast pace. Treatments, cures, and vaccines for various diseases and disorders are being developed constantly, and yet, coronary heart disease remains the number one killer in the world. The media today concentrates intensely on drug and alcohol abuse, homicides, AIDS and so on. What a lot of people are not realizing is that coronary heart disease actually accounts for about 80% of all sudden deaths. In fact, the number of deaths from heart disease approximately equals to the number of deaths from cancer, accidents, chronic lung disease, pneumonia and influenza, and others, COMBINED. One of the symptoms of coronary heart disease is angina pectoris. Unfortunately, a lot of people do not take it seriously, and thus not realizing that it may lead to other complications, and even death. THE HUMAN HEART In order to understand angina, one must know about our own heart. The human heart is a powerful muscle in the body which is worked the hardest. A double pump system, the heart consists of two pumps side by side, which pump blood to all parts of the body. Its steady beating maintains the flow of blood through the body day and night, year after year, non-stop from birth until death. The heart is a hollow, muscular organ slightly bigger than a person's clenched
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
How much energy is there in some foods that you eat?
How much energy is there in some foods that you eat? Food Mass of the food (g.) Temp. of the water before the test (?C) Highest temperature of the water during the test (?C) Temp. increase (?C) Kit Kat 3.74 22 00 78 Rice cake 3.55 25 90 65 Peanut 3.72 25 90 65 White bread 3.36 25 57 32 Digestive biscuit 3.44 25 61 36 The mass of water in the boiling tubes- this apply to all of the foods test P= 1g. /cm Mass = 1g. /cm x 20cm = 20g. The energy transferred to the water in the boiling tube Mass of water = 20g Energy transferred to the water- P= m/v The energy transferred to water = m x c x T Specific Heat capacity = 4.2 J/g. Food The change in temp. (?C) Energy transferred to the water (working) m x c x T Answer in (kJ) Kit Kat 78 20 x 4.2 x 78 6552 Rice cake 65 20 x 4.2 x 65 5460 Peanut 65 20 x 4.2 x 65 5460 Bread 32 20 x 4.2 x 32 2688 Biscuit 36 20 x 4.2 x 36 3024 The energy released per gram of food burn Food Mass (g) Energy released from food to the water (working) Energy transferred / mass of food Energy released from the food (kJ/g) per 100g. Energy released per gram (kJ/g) Kit Kat 3.74 6552/3.74 751.9 7.519 Rice cake 3.55 5460/ 3.55 538 5.38 Peanut 3.72 5460/ 3.72 467.7 4.677 Bread 3.36 2688/ 3.36 800 8 Biscuit 3.44 3024/ 3.44 879.1 8.791 Compare Results from Food Table
Coastal Ecosystems: Rocky shores
Coastal Ecosystems: Rocky shores Contents: . The nature of the environment 2. Distribution on the rocky shore 3. Structure of the community 4. The rocky shore system 5. Adaptations to life on the rocky shore . The nature of the environment Constant features: * It is intertidal, and is therefore subject to varying degrees of submersion and emersion * It has a rocky substrate. This is difficult to bore into, so organisms have to sit on the surface and be exposed to the elements. Variable features: * Topography: can have steep cliffs or gentle platforms, smooth slopes or irregular, weathered patterns. This is turn affects how exposed organisms are to the elements. * Exposure to waves: as discussed in the first week, some shores face the open sea, some are in sheltered bays or channels. * Temperature: Some face north, some south, and emersion is therefore less or more dangerous. So, for the nature of the environment, think of intertidal, rocky, variable. 2. Distribution on the shore The predominant pattern is one of bands or zones parallel to the water's edge. The rocky shore is inhabited by marine organisms, and the zones therefore represent replacement of species along a marine/terrestrial gradient by creatures better able to tolerate emersion. A zone is therefore a region where conditions favour a particular species, and that species is dominant.
Factors that affect the respiration of immobilised yeast.
Felix Simpeh Biology Coursework Factors that affect the respiration of immobilised yeast Date Completed: Thursday, 20 March 2003 To start off this experiment I feel that it is suitable to explain the main facts of this study. Below is a section explaining respiration and immobilised yeast in detail. Like all living organisms, yeast has to make energy, stored as ATP to carry out all cellular functions. To do this they can respire aerobically when there is plenty of oxygen, or anaerobically where oxygen is short, by this, they are called partial anaerobes. This produces less energy, but keeps the yeast alive. Pyruvic acid has to be broken down in respiration when formed by breaking down of glucose molecules, this can't be done in the same way as it is aerobically when respiring anaerobically which is how the carbon dioxide and ethanol is formed through the zymase. Here is the equation for the aerobic respiration: - Glucose + oxygen => energy + carbon-dioxide + ethanol Yeast can also respire without oxygen but less energy will be released. Respiration without oxygen is known as anaerobic respiration. When yeast respires anaerobically it produces alcohol. The reaction has the following equation: - Glucose => energy + alcohol + carbon-dioxide Cells, such as yeast are often used in industrial processes. At the end of the process the yeast is often mixed up with the
Do Higher Carbon Dioxide Levels Lead to Warmer Conditions?
7/01/04 Do Higher Carbon Dioxide Levels Lead to Warmer Conditions? Analysis From the graph, one can clearly see a pattern between the air and carbon dioxide. Both rise steadily until 20 minutes and then when the lamp is turned off, they both decline. After the first 10 minutes the temperature of the air is 21.90°C and the temperature of the carbon dioxide is 22.40°C, so there is a difference of 0.50°C. After 20 minutes the temperature of the air is 22.70°C and the temperature is 23.30°C, and there is a difference of 0.60°C. This shows that the carbon dioxide has increased by 0.10°C. After 30 minutes the temperature of the air was 21.70°C and the temperature of the carbon dioxide was 21.90°C. So you can see already, that after 10 minutes of the light being switched off, that the temperature gap between the air and carbon dioxide is getting smaller already. After 40 minutes the temperature of the air was 21.15°C and the temperature of the carbon dioxide was 21.45°C. Although both of these temperatures have lowered, the gap has stayed the same indicating that carbon dioxide retains temperature better than air. When the lamp was on, the carbon dioxide heated quicker than the air. After 5 minutes there was a gap of 0.40°C and after 20 minutes that gap had increased by 0.01°C. This shows that as time increases the carbon dioxide takes in more heat energy, getting
The Homeostatic Mechanisms
Homeostatic mechanism P5. Homeostasis is a process in which the body maintains a constant environment internally (which includes our body temperature, glucose levels, PH levels and water levels), regardless of any changes that occur externally. • Skin- regulates body temperature • Hypothalamus- responds to any change in environment • Liver and pancreas- regulates blood glucose and water levels within the body • Kidneys- regulates water and salt levels Homeostasis is maintained by negative feedback control, which is the process where a receptor such as nerve ending in the skin, detects change in the environment and informs the brain, which then instructs the effector such as a muscle or a gland to perform an action. Homeostasis is vital as it allows the enzymes within the body to function efficiently, as they work better when under a constant temperature. This is important because enzymes are essential for speeding up metabolic reactions that take place within the body which are required for the body cells to function correctly. Therefore, without homeostasis, the enzymes would not function which would be fatal. There are various parts of the body which are involved in homeostasis including; Homeostasis is responsible for the maintenance of many things that take place within the body, such as: Blood glucose levels Homeostasis
Investigation into how Lichen growth is affected as you move further away from a river
Investigation into how Lichen growth is affected as you move further away from a river Vikram Singh Mahal ________________ Investigation into how Lichen growth is affected as you move further away from a river Abstract The purpose of this investigation was to observe and analyse the how the abundance of water affects Lichen growth. I selected 3 sites where there was a river and selected a spot at each randomly. Then I did a 10m line transect from the river to the embankment and recorded any lichen every 1m. I then moved the line transect 2m down the river and repeated the experiment. I did this until I had moved the line transect 12m from the original location that I stated at. The result showed that location on a river bank affected the size of lichens that grew. Experimental Hypothesis: As you move further away from the river bank lichen growth will increase and there will be less abundance of species. Null Hypothesis: There will be no difference in growth and abundance of lichen as you move away from the river bank. Research and Rational This experiment aims to investigate the effect of water abundance of the growth of lichen and which species of lichen are more abundant with increased water abundance. Lichen is an organism that is formed by the symbiotic association of a fungus and an alga or cyanobacterium and occurs as crusty patches or bushy growths on tree
How does caffeine affect the heart rate of Daphnia?
Mohamed Ahmed Does caffeine affect heart rate? The purpose of this experiment is to investigate the effect of caffeine on the heart rate of Daphnia (water fleas). Daphnia are tiny aquatic invertebrates that are suitable for this experiment because they’re abundant, easily obtained, transparent and have very simple nervous system. Hypothesis: I think that a Daphnia subjected to a caffeine solution will show a rise in heart rate, this rise in heart rate should reflect the concentration of caffeine in a given solution. This is because caffeine is a stimulant that speeds up the body affecting the nervous system and rate in which the nerve pulses are sent and received in humans. I produced a detailed plan for an experiment that allowed me to test my hypothesis using the following materials: . Pipettes 2. Test tubes 3. Stop clock 4. Microscope . Daphnia 2. Cavity slides 3. Distilled water 4. Caffeine solutions 5. Cotton wool Plan: . Use a range of caffeine solutions of different concentrations and a control solution that has no caffeine in it at all (so I have a set of results that I can compare to) 2. Place a few strands of cotton onto the cavity slide; this will help restrict the movement of the Daphnia making it easier to see under the microscope. Using a pipette transfer one Daphnia into the dimple of the cavity slide. 3. Place the slide onto the stage of a
Biological Cycles
One of the main biological cycles is the nitrogen cycle, in which nitrogen is used and regenerated in four stages. Nitrogen fixation is when nitrogen gas in the atmosphere is turned into ammonia by Rhizobium bacteria and this ammonia can then be used by plants. The bacteria are found on root nodules of legimous plants, and the two form a mutualistic realationship. In return for the bacteria supplying the plant with ammonia, the plant supplies carbohydrates for the bacteria. The next stage is ammonification where nitrogen compounds from dead organisms and also animal waste is turned into ammonium compounds by decomposers such as saprobiotic bacteria. The third stage is Nitrification where ammonium compounds in the soil are changed into nitrogen compounds that can then be used by plants. First nitrifying bacteria change ammonium into nitrites, then other nitrifying bacteria called Nitrobacter turn nitriles into nitrates. Denitrification is when nitrates in the soil are converted into nitrogen gas by denitrifying bacteria, During this process the bacteria use nitrates in the soil to carry out respiration and produce nitrogen gas which then goes back into the air. This only happens under anaerobic conditions e.g in waterlogged soils. Another crucial biological cycle is the carbon cycle. All organisms need carbon to make essential compounds, therefore it is important that it is
