The Effect of Caffeine on the Heart Rate of Daphnia

According to the results, the columns of caffeine in figure 1, of this experiment the hypothesis for caffeine is partially accepted. There is an increasing trend in the change of pulsation rates with increasing

Next we removed the excess solution from the Daphnia and flushed it with aquarium water. Using the same procedure we monitored the effects of 1 1/2% and 2.0% caffeine

After the Daphnia was given time to calm down, the team took a reading of its heart rate at room temperature (27 degrees C). The reading was taken by counting the heart beats for ten seconds and then multiplying by six to yield beats per minute. Next, a glass Petri dish was filled with ice water at five degrees Celsius. The cold water Petri dish was placed on the stage of the microscope, and the Daphnia was placed on top of the dish. When the Daphnia had been given a minute to acclimate to the changes, another heart rate reading was taken. Then the same procedure using the Petri dish to changed environmental conditions was used with cold tap water (23 degrees), warm tap water (30 degrees), and hot tap water (45 degrees). A heart rate reading was taken for each temperature.

In Exercise 1, diaminofluorene is used to determine the hemoglobin concentration in the daphnids. A higher hemoglobin concentration is indicated by a darker blue color. A spectrophotometer was used to determine the absorbance at 610nm. When measuring the absorbance levels a blank is necessary to have a zero reference, the blank is the “starting point” for the measurements of the sample (re-word). The blank consists of 10µL of diaminofluorene(DAF), 50µL of hydrogen peroxide, and 0.5mL of PBS. The PBS acts as a buffer in this experiment. The cuvette with the sample of daphnids consisted of 10µL of DAF, 50µL of hydrogen peroxide, and 0.5mL of the sample of Daphnia. In Exercise 2, the Pasteur pipette was used to obtain the sample of Daphnia. The depression slide used in this experiment isolated the daphnid, cotton was used to keep the daphnid still while the heartbeat was counted. The ocular micrometer on the microscope allows the tail spine length to be measured accurately, as well as using an ocular magnification table.

Considering a diagnosis of dehydration, along with the fact that Joe seems to be consuming a lot of caffeine, a diuretic that causes fluid loss, the student may suggest testing Na, Ca, and other electrolyte levels in the blood, as well as levels of caffeine or other metabolites in the blood and urine. This latter information may help the student determine or at least estimate Joe’s caffeine intake.

B. Caffeine affects each and every one of us differently. What could happen to one of us may not happen to anyone else.

Thesis: Caffeine can have many different effects on the body depending on the amount of consumption.

Then using a disposable pipette we placed two drops of room temperature water (21 degrees) on top of the Daphnia. Then placing it careful under the microscope with a for 15 seconds using a tally counter and clicked away how many heart beats we observed and did this three times for three trials, in between the times would give the daphnia a two minute recovery period. We then would process the trials information and calculate an average. After the information calculated we then  multiplied our results by four to see the average heart beats per minute with room temperature water. We gave the daphnia five minute to recover then went on to proceed with two drops of hot water (40 degrees celsius) placed on top of the Daphnia using the pipette. Again three trials for 15 second using the tally clicker following after a two minute break. The same followed for the cold water (0 degree celsius) placing two drops on top of the Daphnia administered by pipette. In between the transitional water temperature trials we then cleaned up the excess water before placing new drops of water by gently soaking up the water with kimwipes. After five minutes we tallied the heartbeats of the Daphnia before administering the epinephrine. Then again gently gave two doses of epinephrine using a new pipette. Then after we observed and tallying the heart beats before administering the epinephrine, three times again recording our results then averaging it. Then we placed two drops of the epinephrine on top of the daphnia, tallying the heartbeats and recording and calculating our trial results. Then after two minutes we observed and tallied the effects after the epinephrine had been used.  Each trial again consisted of observation under the microscope, tallying and observing the behavior internally and externally of the

In this experiment we find how caffeine can affect the heart rate of a culture Daphnia. Heart rate of a living organism’s can vary depending on the individual, age, body size, heart conditions, medication use and even temperature. This report will examine if the caffeine is good or bad for the living organism’s health and body. And discuss about where the caffeine is produced and used in daily life of human beings and on the environment. Daphnia is a water flea used in this experiment because of its genomic infrastructure with wide range of phenotypic diversity. This quality of Daphnia makes them a versatile model for the experiment. Also their transparent body allows the experimenter to visually see how the heart beats and count them under the light microscope during the experiment as required. The heart rate of Daphnia is monitored under different concentration of caffeine solution and the results are shown in a table and a graph. Experiment carried out to locate the effects of caffeine on a heart rate of Daphnia may or may not be a predictor of change in human heart rate under caffeine. The effects of caffeine can also be tested on humans but those experiment involving humans contains high risk, as Daphnia can only live for a short period of time and in nature most of them get eaten within their first few days or weeks of life.

An independent samples t-test was conducted to examine the difference between experimental conditions on test performance. The results indicated a significant difference between participants who consumed the caffeinated beverage and participants who did not, with participants in the caffeinated group (M = 7.64, SD = 2.41) performing worse than participants in the non-caffeinated group (M = 9.81, SD = 3.16), t (97) = 2.14, p < .05.

My hypothesis was, as the concentration of alcohol increases the lower the heartbeat of the Daphnia will fall. To test my prediction I carried out 25 individual experiments which were all carried out using the same procedure but varying the alcohol concentration of the solution. To investigate how alcohol concentration affects the heartbeat of Daphnia I recorded the heartbeat of 25 Daphnia for a period of 7 minutes. This included 1 minute before submersion in alcohol, 3 minutes during submersion in alcohol and 3 minutes after submersion in alcohol. I then found the percentage decrease of the heartbeat of the Daphnia from the resting heart rate.

Daphnia are used to test water toxicity, they are a vital part of fresh water ecosystems. They are a food source for smaller fish and invertebrates and considered to be a consumer of algae and bacteria (Elbert, 2005). These small crustaceans range in size from 2-5mm long and are commonly referred to as water fleas. Daphnia belong to the group called Daphniidae, which is a relative of freshwater shrimp. It is easy to see the internal organs of daphnia because of a transparent taco shell like carapace. A carapace is the hard outer part of a shell or covering. A daphnia’s life span can range between 1-56 days. (Elenbaas, 2013; Clare 2002). The comfortable pH level for daphnia is between 7.2 and 8.5 (Clare, 2002).

1. Keep tabs; look at the labels to see how much caffeine is in product.

-Test your hypothesis by doing an experiment: A group of 11 mice where given water while coffee was given to another group made up of 10 mice.

way to tell how much caffeine is in a product? These are all things i am going to touch on in this