Diagram:
Method:
In my science experiment I hope to prove that the more caffeine that is consumed the higher the pulse rate and the quicker the reaction time. I will consume the Coca-Cola in increasing amounts and observe the affect the caffeine (present in the Coca-Cola) has on my pulse rate.
I will do this by finding my resting pulse first and then consuming increasing amounts of Coke between 25 and 225 cm3, in volumes of 25 cm3 e.g. 25, 50, 75cm3 etc.
Firstly I will record my resting pulse rate on each occasion, and then after 1 minute, 2 minute, 3 minute and four minutes. Each time I shall wait for my pulse to go back to resting rate before drinking the next volume of coke.
I shall take the pulse from the carotid pulse in my neck. I propose to do each of the tests at least three time and take an average. I will record the results of my pulse and then plot a graph.
THINGS I NEED TO DO TO MAKE IT A FAIR TEST:
- Measure the amounts of coke accurately by using a measuring cylinder of an appropriate size.
- Measure the amount of hot water I will consume for the coffee
- Always wait for my pulse to go back to resting before starting the next test.
- Using the type of coffee and coke all the time.
- Use an electronic pulse meter to give me more accurate results than counting the heart beat yourself
APPARATUS:
2 litre bottle of coke which contains caffeine, Accurate measuring cylinders (appropriate size), 1 stop clock, Paper and pencil to record down the results.
SAFETY:
1.)Make sure that the measuring cylinders and the cups are completely sterile, to make sure that you don’t get ill.
- No running around the science lab, because you could trip and hurt yourself.
- When consuming the coffee take care not to scald yourself
Results:
Graph to show the relationship between amount of caffeine consumed and heart rate.
Conclusion:
My results show that the more caffeine consumed the higher the pulse rate was. This is the same as I had predicted in my theory. It also shows that the more caffeine consumed the quicker the pulse rate rose. All of the plotted lines follow a similar pattern, by starting off low ( the resting pulse rate) and then rising up quite quickly and then slowly decreasing.
Evaluation:
Although my results overall were quite good there still might be the possibility that they are not quite perfect ( an anomalous result). For example to get a better result I would have done the experiments another three times to get a much better average if I had had the time. On the graph there was an anomalous result for 150cm3 as shown. This may have been an error in my counting of my pulse, or there may have been slightly too much coke that experiment. To have made the measurements even more accurate I could have used a burette because it would have given a much more precise measurement. To improve the accuracy of pulse rate a medical heart rate monitor would have been more accurate.
Because of the constraints of time it was not possible to take all the readings in the same lesson period. The smaller quantities were taken during a lesson after morning break (during which I had eaten), which the larger volumes were consumed during a lesson before lunch when my stomach was empty. The varying presence of food in my stomach could alter the absorption of the caffeine into the blood stream.
Taking all these factors into account the results obtained gave a satisfactory correlation between pulse rate and amount of caffeine consumed.
