• 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 in Daphnia

Extracts from this document...

Introduction

'Does Caffeine Affect Heart Rate In Daphnia?' Effect of Caffeine on Heart Rate in Daphnia TITLE 'Does caffeine affect heart rate?' HYPOTHESIS I predict that the water fleas heart rate will increase as caffeine is added. METHOD The Investigation was carried out in the following way: * A few strands of cotton wool were placed on a cavity slide (this helped restrict the movement of the water flea) * One large water flea was put on a cavity slide using a pipette * Water was removed from around the water flea using filter paper * One-Two drops of distilled water was added (This helped maintain sufficient oxygen supply to the flea) * To keep the temperature in control, a cavity slide was placed under the slide to minimise the amount of heat and light going through to the microscope * Water flea was viewed under low power * Focus was paid to its heart which could be seen through its translucent body * Stop watch was used to record the heart beats per minute * The procedure was repeated using different concentrations of caffeine * Results were recorded in a table RESULTS Table of results: [Caffeine] (mg dm ) ...read more.

Middle

did not fit in with the trend for this concentration. CONCLUSION According to the results and graph, my hypothesis was proved correct (that the heart rate increased as the caffeine concentration was increased). Although the last point in the graph does not follow this. I think this is mainly due to the fact that there were two anomalous results and this affected the calculation of the mean heart rate. DISCUSSION A daphnia's heart will beat faster when it receives a dose of caffeine. Caffeine belongs to a class of compounds called methylxanthines and can block a receptor on the surface of heart muscle cells for adenosine. In fact, it is caffeine's blockade of the A1 adenosine receptor in the heart that causes the heart to pound after a significant caffeine dose. Caffeine and similar compounds also inhibit a class of enzymes known as cyclic nucleotide phosphodiesterases. These enzymes are, in part responsible for degrading a stimulatory signal produced when excitatory neurotransmitters activate different neurons in the central nervous system (CNS). ...read more.

Conclusion

* The amount of caffeine added on the daphnia will vary even though it was added using a dropping pipette. This could account for the anomalous results at the 7.5 and 10.0 mg dm concentration of caffeine. Limitations: * The whole experiment should be repeated atleast twice to make the results more reliable * A stethoscope could be used for accuracy of results, but this is not safe to use. * If the caffeine was added in smaller doses, i.e. the concentration did not increase so rapidly, e.g. if we increased the concentration by 0.5 mg dm then we could have seen a clearer pattern relating the concentration of caffeine and its effect on heart rate. RISK ASSESSMENT Care had to be taken in the duration of this experiment. This was because the concentration of caffeine could have a big impact on the daphnia. Too much caffeine could kill the daphnia and too much water could fill the daphnia's lungs up and also kill them. These factors had to be taken into consideration when doing the experiment. This experiment was fairly accurate in terms of ethical considerations. The only errors may have come from human errors, which are unavoidable. A Level Biology BIOLOGY SALTERS 1 ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our GCSE Humans as Organisms 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 GCSE Humans as Organisms essays

  1. Marked by a teacher

    Biology Revision notes - Human Biology

    5 star(s)

    DNA - Deoxyribose Nucleic Acid (also DeoxyriboNucleic Acid) 46 chromosomes come from the egg and sperm (23 from each) and combine to form a unique baby with unique genes. Genes are sections of long strings of DNA which codes for 1 characteristic. Each chromosome has hundreds of genes along its length.

  2. Marked by a teacher

    Is the MMR vaccination safe?

    5 star(s)

    They prefer the choice of separate vaccinations as there has never been any link to the autism and because they feel the combined MMR, with three vaccines at once, will overload their child's immune system. However, there is no scientific evidence to prove either of these things; the only recommendation

  1. Peer reviewed

    the effect of caffeine on heart rate

    3 star(s)

    I also would do the same experiment by drinking tea or normal water to compare the results to obtained results. My present experiment went along as I expected and I had a fair test because I didn't have any anomalous results.

  2. Human biology short notes

    contraction becomes more frequent and intense * Amniotic membrane ruptures and releases amniotic fluid * The cervix dilates allowing the baby to pass into the birth canal and eventually out * After birth the placenta and uterus linings discharge * And the umbilical cord is tied and cut Lactation *

  1. The Effect of Caffeine on the Heart Rate of Daphnia.

    The 0.01-mol caffeine solution is not strong enough to harm the daphnia. Following the experiments every daphnia will be returned to its colony. I will take every care not to stress the daphnia by being gentle as possible with them and not disturbing their habitat.

  2. Should you vaccinate using the HPV vaccine?

    Consequently it would still be necessary for you to still have Pap screening. - Following the point above, it is important that you vaccinate to at least protect yourself from as much as you can. Merck, the creator of Gardasil did a study.

  1. The Effect of Substrate on

    Care must be taken to avoid cross contamination of the chemicals which could affect the results of the experiment. Preliminary a) Aim To determine suitable concentrations and volumes of yeast and the sugar solutions for use in the main experiment and to suggest improvements for the final method.

  2. INVESTIGTING THE EFFECT OF CAFFEINE CONCENTRATION ON

    Apparatus - The following will be needed in order to carry out the experiment * Culture of daphnia to examine the dependant variable upon (heartbeats). * Micro-pipette to acquire the Daphnia. A small hole at the bottom of the pipette will ensure that only the right amount of Daphnia are acquired, as Daphnia are very small fragile creatures (about 3mm)

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