The purpose of this experiment was to study the effects of ethanol on the cellular respiration of mealworms. Cellular respiration is the process by which cells harvest the energy stored in food. It is the intake of oxygen and energy in the form of glucose, and the cells ability to break it down into carbon dioxide, water, and energy required for the body to function. More scientifically, it is a three-step pathway that produces ATP (adenosine triphosphate.) The three stages of cellular respiration are: glycolysis, the citric acid cycle, and electron transport.
Ethanol is a volatile, colorless liquid and is considered a psychoactive drug. Ethanol is generally known to have depressant effects on the central nervous system. If you subject mealworms to a 95% ethanol solution, then the rate of cellular respiration will decrease.
Materials and Methods
The materials used in this experiment were: 12 beetle larvae (mealworms), 1 – 250 ml Erlenmeyer flask, a ring stand and clasp, a Data logger, an AC power adapter for the data logger, forceps, filter paper, 95% ethanol solution and a dropper. The experiment began by adding 12 live mealworms to the flask. The data logger was then calibrated and used to take an initial CO2 output reading. Readings were again taken every minute for a total of 15 minutes. These readings were recorded and used as the control. Next, the dropper was used to add 7 drops of the 95% ethanol solution to the filter paper. The filter paper was inserted into the flask with the mealworms. The data logger was again used to take CO2 output readings at one-minute intervals for 15 minutes.
Results
This experiment showed the effects of ethanol on the cellular respiration of mealworms. Respiration rates were recorded in both the control group (no ethanol) and the experimental group (ethanol.) The initial readings in the two groups were very different, with the control group starting out with a much higher rate than the experimental group. Both groups showed progressively increased rates as time elapsed.
Overall, the CO2 output in the control group, with no ethanol, increased by 690 ppm over the 15 minutes, producing an 81.18% change. The experimental group, with the 95% ethanol solution, increased by 857 ppm, producing a 125.11% change.
RATE OF CELLULAR RESPIRATION IN BEETLE LARVAE WITH/WITHOUT ETHANOL | Time Intervals Minutes | Control Treatment No Ethanol | Experimental Treatment 95% Ethanol | | | | 0 | 850 | 685 | 1 | 915 | 760 | 2 | 971 | 844 | 3 | 1031 | 920 | 4 | 1083 | 982 | 5 | 1128 | 1046 | 6 | 1177 | 1108 | 7 | 1222 | 1169 | 8 | 1266 | 1212 | 9 | 1307 | 1267 | 10 | 1349 | 1311 | 11 | 1397 | 1367 | 12 | 1436 | 1414 | 13 | 1475 | 1462 | 14 | 1513 | 1503 | 15 | 1540 | 1542 | Change in CO2 (ppm) | 690 ppm | 857 ppm | Percent Change in CO2 (%) | 81.18% | 125.11% |
Discussion
Our hypothesis stated that, if we subjected the mealworms to the ethanol, then the rate of cellular respiration would decrease. Our experiment did not support our hypothesis. In fact, the opposite was documented. The control group, with no ethanol, produced an 81.18% increase in CO2 production over the elapsed 15 minute time period. However, the experimental group, with the 95% ethanol, produced an increase of 125.11% CO2 production over the same elapsed time. Why would ethanol, a depressant, produce an increase in cellular respiration?
One possible explanation is that our initial readings in each group were not consistent with each other. The control group initial reading was 850 ppm; whereas, the experimental ethanol group started out much lower at 685 ppm. These initial readings do support our hypothesis that cellular respiration was decreased in the mealworms subjected to the ethanol solution. It is only with the elapsed time that the ethanol treated mealworms had increased respiration rates. It was also interesting to note that after 15 elapsed minutes, both groups ended up with nearly identical total CO2 output. The control group ended with 1540 ppm and the ethanol treated group with 1542 ppm.
You May Also Find These Documents Helpful
-
The biological hypothesis for this lab experiment was that the rate of respiration in mealworms would decrease in mealworms that were exposed to a dark environment compared to those mealworms that were exposed to a light environment. This hypothesis was based on the fact that oxygen levels tend to decrease in light deficient environments. Due to limited oxygen, citrate concentrations found in the citric acid cycle are high and affects the activity of the enzyme phosphofructokinase, which is found in the early stages of glycolysis and catalyses the conversion of fructose 6-phosphate to fructose 1,6-bisphosphate, by slowing down its function and therefore slowing down cellular respiration (Russell, Hertz, McMillan, Fenton, Addy, Maxwell, Haffie, MIlsom 2014). The null hypothesis was that the rate of respiration in mealworms would not change if they are in a dark environment from those in light environment. The alternate hypothesis was that there will be a decrease in the rate of respiration in mealworms from the dark environment.…
- 1032 Words
- 4 Pages
Good Essays -
The circulatory system is important in circulating blood, nutrients, oxygen and chemicals to the body. A circulatory system commonly consists of the fluid it contains, such as blood, a pumping vessel such as a heart, and the vessels, which carry the fluid through the body. In a closed circulatory system, the fluid, blood, is contained within the vessels as it circulates through the body. The Lumbriculus variegates, or blackworm, is commonly found in stagnant water along the edges of marshes and ponds. Blackworms have a closed circulatory system, which in the blackworm includes a large dorsal blood vessel [1]. Glucose is the most common carbohydrate and is classified as a monosaccharide and is a reducing sugar. Glucose is called blood sugar as well because it circulates in the blood. When blood glucose is high, the pancreas releases insulin, which then helps to transport glucose into muscle or liver cells. There, it's used for energy. If there's more glucose present than needed, insulin helps the glucose to be stored in adipose tissues as fat for potential future energy needs. One immediate effect of the breakdown and conversion of glucose into cellular energy is an increased metabolism, which can manifest itself in the form of increased heart rate, high blood pressure or some other form of arousal such as heightened mental alertness [4].…
- 486 Words
- 2 Pages
Good Essays -
An experiment was conducted to study and explore the circulatory system by exposing Lumbriculus variegatus, black worms, to household drugs. Lumbriculus variegatus was chosen as the experimental organism because of their transparent bodies and their simple physiology.…
- 1795 Words
- 8 Pages
Better Essays -
A stimulus is an environmental change that directly influences the activity of a living organism or one of its parts.…
- 1050 Words
- 5 Pages
Powerful Essays -
Purpose: The purpose of this lab was to gain a complete understanding around the rate of cellular respiration within multicellular organisms, also to research and understand how to use a CO2. Background: Living systems require free energy and matter to maintain order, to reproduce, and grow. Energy deficiencies cause disruptions at the population and ecosystem levels as well. 1 mol of H2O produces 1 mol of CO2 through cellular respiration. Autotrophic organisms capture free energy from the environment through the process of photosynthesis and chemosynthesis.…
- 704 Words
- 3 Pages
Good Essays -
Ethanol was given at 0.1mM and 1.0mM. The pulse rate difference was 10.31. Caffeine was given at 0.1mM and 5mM. The pulse rate difference was 1.7241. Since the worms were small and weighed little, they absorbed the drugs at a faster rate. Within 5 minutes the drugs had affected their original heart rate. The worm’s size and the worm’s heart rate work together. This experiment is valid because the worms at first we’re more active and after the drug was administered they became more still. With a higher concentration of alcohol the worms’ ends began to curl while their bodies stayed straight. For the most part, their pulsation rates decreased because alcohol is a depressant. Alcohol causes the organisms to feel sluggish and if a higher dosage was administered to the worms neurological damage could have occurred. The findings are reliable because those that also used alcohol with the worms conducted similar findings. With a smaller dose of ethanol, the change in pulse rates from initial heart rate to final heart rate was more in the negatives. Meanwhile, caffeine is an excitatory drug and causes organisms to experience bursts of energy. Caffeine is an antagonist, which means that it occupies receptors without activating them. It caused the worms to curl up and stretch, as their pulses increased. Then nicotine caused the worms to become more…
- 882 Words
- 4 Pages
Good Essays -
The objective of this lab was to figure out which has a higher cell respiration rate between crayfish and elodea. In order to figure this out we first set up three beakers to represent our control, elodea and crayfish and filled them with 75mL of culture solution which were dechlorinated making the solution acidic. We then had to place both the elodea and the crayfish in separate beakers filled with 25mL of water. The increase in volume of the water would represent the volume of the two test subjects. We then covered each beaker with plastic, but for the elodea we placed it under a can so it could be in the dark. After waiting 15 minutes to allow them to respire we took it out and add four drops of phenolphthalein, which was also acidic, to both beakers. Once both beakers got their four drops we added drops of NaOH, which was a base, until the solution turned pink. Our results were that the respiration rate of the crayfish was higher than the elodea.…
- 717 Words
- 3 Pages
Satisfactory Essays -
|Record your observations about mealworms (shape, size, number of legs and segments, |Draw a detailed picture of your meal worm. |…
- 994 Words
- 4 Pages
Powerful Essays -
Woodman JD, Cooper PD, Haritos VS. 2007. Cyclic gas exchange in the giant burrowing cockroach, Macropanesthia rhinoceros: Effect of oxygen tension and temperature. Journal of insect physiology 53, pp. 497-504…
- 1199 Words
- 5 Pages
Good Essays -
Cellular respiration includes the processes of glycolysis, krebs cycle, and the electron transport chain. Glycolysis is used to convert glucose to produce two pyruvate as well as 4 ATP’s and 2 NADH but uses 2 ATP to have a net product of 2 ATP and 2 NADH. The krebs cycle converts pyruvate to Acetyl CoA, which produces 2 ATP,8 NADH, and 2 FADH’s per glucose molecule. Electron transport Chain is the last and most important step of cellular respiration, it makes ATP with the movement of electrons from high energy to low energy that makes a proton gradient which makes ATP, this cannot occur unless oxygen is present. Fermentation is an anaerobic process in which converts sugars into acids, alcohol, or alcohol. This process occurs in yeast and bacteria as well as muscle cells that have no oxygen left. In yeast fermentation produces ethyl alcohol and carbon dioxide from glucose and fructose. Fermentation in bacteria cells the process of fermentation produces ethanol, while in human muscle cells fermentation produces lactic acid in cells that have a short…
- 1719 Words
- 7 Pages
Better Essays -
Temperature and environment plays a key role on the effects of an ectothermic organism’s metabolism. The specific ectothermic organism used in this study was the Gromphadorhina portentosa also known as the Madagascar Hissing Cockroach. In this study we measured CO2 production (%) and temperature (̊C) every three minutes for a total of 15 minutes in three different temperature environments. The three temperature environments conducted in the experiment included room temperature, a cold environment (ice bath), and a hot environment (how water bath). The purpose of this study was to test the effects of temperature change on the ectothermic organism Madagascar Hissing Cockroach (Gromphadorhina portentosa) and its metabolic rate. The null hypothesis was that there would be no change in metabolic rate and CO2 gas percentage levels despite changes in temperature. The alternative hypothesis was that the CO2 gas percentage levels from the ectothermic organism would change with changes in temperature. Our findings reject the null hypothesis and agree with the alternative hypothesis reflecting that the CO2 gas percentage levels from the ectothermic organism did change with changes in environmental temperature.…
- 1217 Words
- 5 Pages
Powerful Essays -
Blackworms (Lumbriculus variegatus) were used in this experiment to study the effects of secondary plant compounds, chemical compounds produced by plants that are not part of the general metabolism, on pulse rate. Secondary plant compounds act as defense mechanisms which reduce or eliminate consumption of some plant species or even attract predators. These compounds are not essential to the plant but often benefit the plant by having harmful effects on animals. These deterrents can include toxins, increased volume of urine, or even affect water balance but they include a wide variety of physiological consequences (Dearing et al, 2002).…
- 453 Words
- 2 Pages
Satisfactory Essays -
1.)Get container deep enough so mealworms can't crawl out, with holes for them to breathe.…
- 253 Words
- 2 Pages
Satisfactory Essays -
Cellular respiration is the set of the metabolic reactions and processes that take place in the cells of organisms to convert biochemical energy from nutrients into adenosine triphosphate (ATP), and then release waste products.…
- 377 Words
- 11 Pages
Satisfactory Essays -
The 95% confidence intervals describe the extent of experimental errors within this experiment. Experimental errors give imprecise measurements for result analysis. If the actual temperature recorded was not exact compared to the desired temperature, the results may give false belief. Other experimental errors that can affect cricket respiration rate is how far the respiration chamber is submerged in the water baths, not allowing the crickets to acclimate at new temperatures before recording CO2 concentration, incompetency in eliminating previous CO2 from different temperature stations before starting a new trial, and the possibility of the drierite dessiccant failing to absorb excess moisture. Even though experimental errors are inevitable, the results do show that as temperature increases, cricket respiration rate also increases. Since crickets are ectotherms, they tolerate inconsistent body temperatures depending on the amount of heat gained from their environment. Crickets use the heat absorbed as a source of energy for their bodies to function and increase metabolism. The more heat absorbed the more energy for cells to do work, such as respire. This explains why the cricket’s respiration rate was the fastest at the warmest temperature 40°C. The results of this experiment support the hypothesis relating temperature and respiration rate of crickets. If respiration is a process of metabolism, then the crickets have a higher metabolism…
- 354 Words
- 2 Pages
Good Essays