"Daphnia caffeine" Essays and Research Papers

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    Does caffeine affect heart rate? Background Information: Caffeine is a bitter white crystalline xanthine alkaloid that acts as a psychoactive stimulant drug. A German chemist‚ Friedrich Ferdinand Runge‚ discovered it in 1819. Plants produce caffeine as an insecticide. It is found in varying quantities in the beans‚ leaves‚ and fruit of over 60 plants‚ where it acts as a natural pesticide that paralyses and kills certain insects feeding on the plants. Cocoa in South America‚ coffee in Africa

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    THE EFFECT OF CAFFEINE ON HUMAN BODY A Term Paper Presented to: Miss. Durano‚ Leony Marie WESTERN MINDANAO STATE UNIVERSITY MALANGAS CAMPUS MALANGAS ZAMBOANGA SIBUGAY In partial Fulfillment of the Requirements for the course English 102 (Writing in Discipline) Second Semester 2011-2012 Presented by: Mr. Reymonel R. Paler CS – 1 March 2012 Table of Contents I – Introduction ---------------------------------------------------- 1 A. Background

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    Isolation of Caffeine from Tea (12A) Introduction When a person drinks tea or coffee‚ it is not pure caffeine. It also has other natural substances. The purpose of this lab was to isolate caffeine from tea leaves. The methylene chloride removed nearly pure caffeine from the basic tea solution. Caffeine is a white‚ crystalline‚ bitter alkaloid‚ C8H10N4O2 ‚ usually derived from coffee or tea. Caffeine is used in medicine chiefly as a nervous system stimulant. Caffeine is used by humans to ward off

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    consume caffeine every day of the year. Caffeine is the ingredient that makes the public crave coffee‚ soda‚ chocolate and many other caffeine-carrying products. Americans consume about 45 million pounds of caffeine each year. In the United States‚ coffee drinkers drink an average of 2.6 cups per day. Total caffeine intake for coffee drinkers was 363.5 mg per day - this includes caffeine from coffee and other sources like soft drinks‚ food and drugs. Non-coffee drinkers get plenty of caffeine as well:

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    to eliminate caffeine from their diet. Central idea: By reducing the use of caffeine‚ individuals can break their addiction and become healthier. They can regain their sleep‚ activeness and become more aware. Introduction I. Imagine‚ you’ve got a math test tomorrow that you’ve hardly studied for and not to mention that a fifteen page paper you’ve also got due tomorrow. It’s already after midnight and you’ve only got 3 pages written. How are you going to stay awake? II. Caffeine is used to provide

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    12). Caffeine acts in the body by getting absorbed in the body through the cells relatively fast‚ after which it is expelled through the liver. The effects are that caffeine being a stimulant in the body‚ a short while after consumption with an increase in wakefulness. When taken in large amounts‚ it causes physical effects like irritability‚ insomnia and even restlessness. 13) + 14) Caffeine passes through the body membranes from the first sip‚ entering your blood stream through the lining of your

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    Stage  1  Psychology   Research  Report   Affects  of  caffeine  on  reaction  time     Proposal:     Caffeine  is  used  by  many  people  to  increase  their  energy  levels.  It  alters  an   individual’s  alertness  and  their  reaction  time.  Though  the  most  common  form  of   caffeine  is  coffee‚  it  can  also  be  found  in  certain  soft

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    The Effects of Caffeine on the Human Body I. In a quote by Eddie Vedder‚ I read "Caffeine‚ the Gateway drug." Around 90 percent of Americans consume caffeine every single day in one form or another. Consuming as little as 100 mg of caffeine a day can lead a person to become "dependent" on caffeine‚ yet it is legal and unregulated in many jurisdictions. Making it the most popular drug by far. In this speech I am going to explain how caffeine affects the Human body. II. Caffeine is believed to

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    Determination of Caffeine in Tea Samples CONTENTS 1. 1. Introduction 2. 2. Theory 3. 3. Uses of Caffeine 4. 4. Effects of Caffeine 5. 5. Procedure 6. 6. Observations 7. 7. Result INTRODUCTION Tea is the most commonly and widely used soft beverage in the household. It acts as a stimulant for central nervous system and skeletal muscles. That is why tea removes fatigue‚ tiredness and headache. It also increases the capacity of thinking. It is also used for lowering body temperature

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    -------------------------------------------------   Isolation of Caffeine from Coffee Date of laboratory work: 10/9/2012 5:00-7:45 Date of report written: 10/15/2012 Introduction: The purpose is to isolate caffeine from coffee by using the organic solvent dichloromethane (CH2Cl2) that is also referred to as direct contact. Calcium carbonate (CaCO3) is used to remove the tannins from the coffee. Afterwards an extraction is used to separate the organic layer (bottom) from

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