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the effect of caffeine on heart rate

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"The effect of caffeine on heart rate" Question: Does the amount of caffeine affect on your heart beat? Pre-test: Before I start my test I have found the number of heart beats of Daphnia before introducing the caffeine and after introducing the caffeine. As the graph shows when we introduced the caffeine to it, its hearth beats increased and after 7 minute it starts to falling down to normal. Prediction: Yes, it does. Caffeine is known as being a drug so as the amount of caffeine increases the hearth beat increase as well. Scientific Reasons: Coke contains caffeine. Caffeine is a drug that stimulates the nervous system which causes the hearth rate to increase. Boys are generally bigger than girls so giving the same amount of caffeine to them has less effect compared to girls. Caffeine causes increased amount of stimulatory neurotransmitters to be released. Also caffeine affects females differently. They not only have a greater sensitivity to caffeine than males but they also may take much longer to detoxify caffeine and recover from its stimulating effects. ...read more.


I will be careful that the temperature of all the fluids is the same Conclusion: The question was: "Does the amount of caffeine affect on your hearth beat?" My results are consistent with my prediction based on my hypothesis. My experiment suggests that caffeine does have a significant effect on heart rate which is due to its action on the A1 adenosine receptor which is found on certain nerve cells like the ones innervating the hearth. Caffeine binds to this receptor causing the second messenger cyclic AMP to increase in concentration in the cell which activates certain protein kinases that increase metabolic activity and thus heart rate, My graphs show the effect of caffeine on female being stronger than males as their metabolism is slower than them and that would cause caffeine to affect on them for a longer period of time. Because caffeine is a central nervous system stimulant that has been shown to boost metabolism and enhance weight loss efforts by increasing fatty acid metabolism and thermo genesis. ...read more.


17 17 23 24 15 20 23 24 21 22 22 17 23 average 17.5 17.5 22.5 22 18 20 21 20.5 19.5 21.5 22.5 18.5 20.5 *DECAFFEINATED COKE Before After Male1 21 20 21 20 21 22 23 21 22 21 20 22 20 Male2 20 20 20 19 20 21 22 21 22 23 21 18 21 average 20.5 20 20.5 19.5 20.5 21.5 22.5 21 22 22 20.5 20 20.5 Before After Female1 22 23 23 24 15 20 23 24 21 22 22 17 23 Female2 21 21 19 22 20 23 17 23 21 20 21 16 17 average 21.5 22 21 23 17.5 21.5 20 23.5 21 21 21.5 16.5 20 *FIZZY WATER Before After Male1 19 21 21 20 20 22 22 23 21 20 21 19 20 Male2 18 18 20 21 19 18 18 19 20 19 18 17 18 average 18.5 19.5 20.5 20.5 19.5 20 20 21 20.5 19.5 19.5 18 19 *NO DRINK AT ALL Female 20 20 25 25 20 18 19 18 19 18 19 20 20 ...read more.

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Response to the question

This piece of coursework offers a sound investigation into caffeine and heart rates, but there is plenty of room for improvement. Through the results collected, it makes it clear that caffeine increases the heart rate, but there is only a ...

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Response to the question

This piece of coursework offers a sound investigation into caffeine and heart rates, but there is plenty of room for improvement. Through the results collected, it makes it clear that caffeine increases the heart rate, but there is only a superficial explanation of why this happens. In my experience, to make it easier to gain top marks, a diagram and graph would have shown higher level understanding.

Level of analysis

The analysis is weak in areas. For example, it is asserted that the same amount of caffeine in boys will have less effect. In my opinion, it would be key to describe how the caffeine concentration in the blood is thus lower, and will have less effect on the nervous system. Although a graph is mentioned, it isn't shown on this piece of coursework. It is essential to show graph-drawing skills and analysis of trends to gain the top marks! Although the essay mentions cyclic AMP and kinases, the understanding isn't shown. In my opinion, showing a diagram explaining what cAMP does will ensure the marker doesn't think this is just thrown in to sound clever. Similarly, they assert that caffeine helps weight loss in their conclusion. It is not right to conclude with a statement that has not been backed up by evidence, and this isn't relevant to the question whatsoever. Staying focussed will ensure the right level of analysis is done which answers the question.

Quality of writing

The spelling and grammar in this piece could be improved. There are a number of times where the essay uses "hearth" instead of heart. Regardless of how strong the content is, slips like this will only make the examiner doubt your understanding of the topic. Similarly a few phrase don't make sense such as "to don't drink at all". In my opinion, a simple proof read before submitting a piece of coursework can save these slip ups from being unnoticed! Remember that there are often marks for quality of written communication, even in sciences.

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Reviewed by groat 11/02/2012

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