"The affect of caffeine on the daphnia heart rate" Essays and Research Papers

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    Extraction of caffeine from Lipton tea leaves Maria Gianna Beatrice L. Cancio*‚ Joe Mari Isabella B. Caringal‚ Rowena A. Chiang‚ Patricia Deanne del Valle Department of Biological Sciences‚ College of Science‚ University of Santo Tomas‚ España‚ Manila‚ Philippines Abstract Caffeine was extracted from Lipton tea leaves by multiple extraction techniques namely solid to liquid extraction and liquid to liquid extraction; the purification by sublimation and melting point determination. Three

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    lObjective This experiment explores how salt and sugar affect the melting rate of ice in water. Research Questions: * Does adding salt to ice and water slow down‚ speed up‚ or not change the rate the ice melts in the water? * Is salt the only substance to have this effect? What about sugar? Knowing how to speed up the melting rate of ice is very important information for anyone who needs to de-ice roads or driveways after a winter storm. While it seems simple‚ adding salt to ice water

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    Extraction of Caffeine from Tealeaves Perez‚ Albert Solomon K.*; Quiambao‚ Marie Angela C;.Pascua‚ Hanna Harriette R.; Patricio‚ Maria Roxanne DC.; 2-Chemistry‚ Department of Chemistry‚ College of Science University of Santo Tomas España St.‚ 1015‚ Manila Abstract Caffeine is soluble in both water and organic solvents‚ solid-liquid extraction and liquid-liquid extraction were used in the experimentation process. Caffeine was extracted using hot water‚ however‚ due to its

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    Extraction of Caffeine from Thea sinensis Abstract Extraction of Caffeine from Thea sinensis main objective is to isolate‚ purify characterized caffeine from tea leaves. Sublimation technique was used to get the % yield which is 0.07%. The melting point of the standard caffeine with the sublimate is 229°C. Introduction The active ingredient that makes tea and coffee valuable to humans is caffeine. Caffeine is an alkaloid; a class of naturally occurring compounds containing nitrogen and

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    An Increase in Light Intensity Increases the Rate of Respiration M. Chauntise‚ S. Shaika‚ R. Shantal INTRODUCTION The sun plays a vital role in sustaining an entire living world whether indirectly or directy using a transformation process called photosynthesis. This process assists in nourishing plants and keeping them alive. For example‚ trees grow very tall in the rainforest where there is an abundance of water in order to reach as much light as they can. For this reason‚ in order to survive the

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    How Variations Of 5‚ 10‚ 15‚ 20‚ And 25 Squats Affects the Respiration Rate In 14 Year- Old Year 9 Boys. The human respiratory system is made up of the lungs and the passages that lead to them. Air is breathed into the lungs‚ and oxygen from the air passes into the blood‚ which carries it around the body. The waste product‚ carbon dioxide‚ is then passed from the blood into the lungs and is breathed out. This all happens with the immense help of oxygen‚ to maintain a functional human body. However

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    Abstract: This lab tests how temperature and pH affect how enzymes will function. The lab showed that temperature will denature an enzyme when past its optimal working temperature and won’t denature in cold temperatures‚ but have slowed molecular activity. pH will also have an affect on an enzymes efficiency‚ when out of optimal pH the enzyme will not function as it is supposed to and if to far out of the optimal pH the enzyme will change shape and no longer work. Enzymes also showed to be reusable

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    the extraction of caffeine from tea leaves to determine its % caffeine. The extraction process selectively dissolves one or more compounds in a mixture into an appropriate solvent. In this experiment‚ it was visible in the process wherein the components of the tea leaves were dissolved in two solvents‚ water and dichloromethane (DCM)‚ with DCM used for multiple extractions. The organic layer was evaporated and the determined % caffeine was 0.12%. Furthermore‚ the purified caffeine was subjected to

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    Pulse Rate

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    The purpose of this practical is to investigate how the pulse rate of humans changes when they exercise. Someone who is physically fit can supply their muscles with enough blood‚ carrying glucose and oxygen‚ for an activity at a lower heart and breathing rate. The fitter you are the lower your resting heart rate. You and your classmates will be the humans investigated. SAFETY: If you know you have any condition that affects you doing exercise‚ please make sure your teacher knows before you start

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    pressure and heart rate differ when measured in a reclining position and in a standing position. When a person stands‚ the heart must pump blood against the pull of gravity to reach important areas such as your brain. Veins must work hard to get blood back to your heart. As a person reclines‚ the heart does not have to pump as hard to reach the same areas‚ decreasing the blood pressure. Also‚ a person is usually more relaxed in a reclining position‚ which slows breathing and heart rate. Less

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