The metabolic rate of an organism is commonly defined as the amount of energy that is metabolised via food or oxygen uptake per unit time. The metabolic rate for organisms plays a pivotal role in certain biological processes and overall maintenance of the organism. There are many ways of measuring metabolic rate but the most common way is to measure the amount of oxygen that is produced provided that there is no anaerobic metabolism. It can be hypothesised that the metabolic rate increases with body mass. This will be done by preparing four vials ensuring that there is soda lime to absorb the carbon dioxide when the organism respires and there is gauze so that the invertebrates namely the ...view middle of the document...
There are several ways of measuring the metabolic rate in animals. These include measuring the amount of heat produced, the amount of metabolic water produced, the difference in energy take up via food and the amount of waste produced via excretion or simply measuring the amount of oxygen used up or the amount of carbon dioxide produced provided there is no anaerobic metabolism(Willmer et al., 2005).
The body temperature of endotherm’s is regulated thus it does not depend on the environmental temperature. The standardized measure of such organisms is known as the Basal Metabolic Rate (BMR). In order for the BMR to be determined the organism must be in its thermoneutral zone (Willmer et al., 2005). There are also organisms that are classified as ectotherms. For these organisms the metabolic rate is directly proportional to the environmental temperature. Thus the resting and fasting phases are called the Standard Metabolic Rate (SMR). This is when there is no spontaneous activity occurring, the digestion of food doesn’t occur and there is no thermal or physiological stress (Willmer et al., 2005).
Living organisms on the Earth vary in their sizes. The oxygen produced will be used as a measure of metabolic rate as it is closely related with the amount of heat produced regardless of whether fat, protein or carbohydrates were metabolized. It can be hypothesized that the metabolic rate will increase with increasing body mass.
Method and materials:
Four shell vials were carefully prepared as follows in order for the experiment to commence. Soda lime was placed into each vial so that it can absorb the carbon dioxide produced because we want to focus on the oxygen consumption. Two pieces of gauze were placed into the shell vial so that the invertebrates didn’t make contact with the soda lime and so that their movement could be restricted. The balance was used in order to measure the initial mass of the vial. Gloves were used in order to obtain the snail, cockroach and crab into their respective vials. The 4th vial remained empty as it was the control. The balance was used in order to take another reading of the mass which will be denoted as the final mass. The difference between the final mass and initial mass will give you the actual mass of the respective invertebrates.
Vaseline was used in order to apply a thin layer of lubricant near the top of the vial so that the stopper containing the pipette was placed in the vial. A thermometer was used in order to record the temperature of the water bath which would be used later in our calculations. The four vials were placed and tilted in the water bath for ten minutes so that acclimatisation can occur to standardize the surrounding water temperature with the organisms inside the vial. Your finger was used in order to close the end of the pipette so that no water bubbles could enter the pipette when the vials were being placed in their respective positions under the water in the water bath. A stop...