• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

Effect of caffeine on heart rate on Daphina

Extracts from this document...

Introduction

´╗┐Effects of caffeine on the heart rate of daphnia Aim: to observe the effects of different concentrations of caffeine on the heart rate of daphnia. Null hypothesis: caffeine has no effect on the heart rate of daphnia. Alternative hypothesis: as the concentration of caffeine increases so does the heart rate of daphnia. Scientific background: Caffeine is a nerves cell stimulant that increases heart rate by the stimulation of cardiac cells. Caffeine does this by blocking adenosine, a neurotransmitter that allows the body to relax. This blockage results in the adrenal gland to release adrenaline hormone, this causes the heart rate to increase, pupils to dilate, your muscles to tighten up, and glucose is released into the blood stream for extra energy. Caffeine also increases dopamine; this activates pleasure parts of the brain which activates the caffeine addiction. Over excess drinking of caffeine could result in restlessness, headaches, and increases blood pressure. Over a long term as the body gets used to the amount of caffeine, it needs higher concentrations for more energy, releasing more and more hormones. ...read more.

Middle

4. Place it under the microscope and count how many times its heart beats in 30 seconds on the stop clock. 5. When 30 seconds has past, stop the clock and record the heart beats in a table. 6. Repeat the sample 3 times with distilled water and record the results. 7. Repeat the method with 0.19% of caffeine concentration on another daphnia, and repeat the sample 3 times then record the results. 8. Do the same with 1.59% caffeine concentration and record the heart beats per 30 seconds on the table. The dependent variable in this experiment is the number of daphnia?s used to determine the increase in heart rate. And the independent variable is the concentration of caffeine used and the different sizes of daphnia used for each sample of caffeine. Repeat: for most of the results, three samples were made for each concentration of caffeine, to ensure that the results are as accurate as possible. ...read more.

Conclusion

This proves that the heart beat was gradually increasing as the concentration of caffeine was. The only anomaly shown is the second 0.19% caffeine solution result (60seconds). Evaluation: The method used did have some limitations like the different sizes of daphnia used for different concentrations of caffeine, some where smaller than others making it harder to read their pulse rate. And some further more active than others making it harder for the experimenter to count the number of heart beats per second. The method overall was accurate enough to use, however more repeats could have been done to ensure reliability of data, on the other hand the equipment used wasn?t as reliable to give accurate results, a device for counting all the heart beats were used their would be less errors in results due to the fact that the experimenter could have made a mistake. The results of the experiment raise questions like could the same effects seen on the daphnia apply to a human heart, and if so then what concentration would show a risk to the health of an individual. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our AS and A Level Energy, Respiration & the Environment section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related AS and A Level Energy, Respiration & the Environment essays

  1. Marked by a teacher

    Effect of nitrate concentration on the growth of Duckweeds

    5 star(s)

    been affected, This is because not as much water entered the plant cells, so in more concentrated solution it would have led to dehydration of the cells. Therefore less growth of fronds takes place. Another major limitation of the experiment was the growth of algae.

  2. Marked by a teacher

    How caffeine affects Daphnia heartbeat?

    4 star(s)

    The group labelled should be used as anomalies as they do not fit in with the trend of the rest of the results, this will make the average more inaccurate.

  1. Investigating the effects of Sodium Hydroxide concentration on Catalase

    Evolution I believe that my result are relievable apart from the two results from 0.01M and 0.001Mconcentartions which also prove my prediction wrong, but this may off been caused by many factors, so these two results are unbelievable, but all the others are.

  2. Investigation into the Effect on Pulse Rate & Breathing Rate During

    When Saleh and Laurence began exercising their nerves of the sympathetic division of the autonomic nervous system more strongly stimulate the SA and AV nodes and the cardiac muscle itself, as a result of this Saleh and Laurence's heart beat became increasingly rapid.

  1. the effect of bile concentration on the activity of the enzyme lipase during the ...

    pH 8 by putting in the same volume of sodium hydrogen carbonate so as long as the pH of the milk stays the same I will not have to alter how much sodium hydrogen carbonate I put in. Temperature Temperature is another factor that affect the activity of an enzyme

  2. Affect of caffeine on heart rate of Daphnia

    can also be a factor affecting the heart rate, if we used different sized daphnia, we would not be directly measuring the affect of 'caffeine' on BPM as we would be taking others factors into account. Plus, it would be sensible to have different persons for each trial measuring the

  1. Investigate the effect of bile salt concentration on the digestion of milk by the ...

    This also reduces the rate of reaction. Non-competitive inhibitors bind to the allosteric site of an enzyme and change the active site slightly; therefore the substrate can still bind to the active site. However, it cannot be changed into its products until the inhibitor has moved. This has a detrimental effect on the rate of reaction.

  2. Respiration Revision Questions and Answers

    There are mitochondrial ribosomes for the assemblage of proteins. Outer membrane It contains proteins some of which will form channels or carriers to allow the passage of molecules. There are also enzymes here. Inner membrane It is impermeable to most small ions including hydrogen.

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work