• 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)

    After much study of the immune systems response of antibodies to the amount of antigens in vaccinations, he claimed that theoretically a child's immune system could respond to 10,000 vaccinations at a time and that if 11 vaccines were given to infants at one time only about 0.1% of the immune system would be used.

  1. Marked by a teacher

    Does Caffeine Affect Heart Rate?

    4 star(s)

    Start Finish 38 55 152 220 173 227 Caffeine 44 65 176 224 48 59 192 236 CONCLUSION: The results obtained clearly show that the higher the concentration of the caffeine, higher the heart rate. This proves the original prediction.

  2. Peer reviewed

    the effect of caffeine on heart rate

    3 star(s)

    Give 2 other males the same amount of fizzy water to drink. Ask 1 female to don't drink at all. Straight after they've drunk their drink ask them to count their hearth beats in 15 seconds for 11 times and record the results.

  1. Human biology short notes

    crying * And the hypothalamus is also triggered by the action of suckling Advantages of Lactation From the child's side * Helps build the mother child bond * Act of suckling on the breast promotes development of the jaw and facial muscles and teeth encouraging speech development.

  2. The heart rate of a Daphnia (water flea)

    pipette 1 thermometer 1 beaker to hold the Daphnia in their new environment 1 kettle some ice some water Prepare a new environment for the Daphnia in a beaker and add a thermometer. Use ice and water heated from a kettle to bring the water up to the desired temperature.

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

    Ethics and Care for the Daphnia Every possible attempt will be made to keep the daphnia alive. I must be careful when immersing the daphnia into liquids because if they are released above the surface air will block the respiratory vents and death will occur.

  2. Should you vaccinate using the HPV vaccine?

    Thus in a few decades the virus could be virtually extinct in the countries vaccinating. Is there a difference between the amount of cervical cancer in developed and undeveloped countries? This choropleth map illustrates where cervical cancer is at a high degree (the darker colour)

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