We are required to obtain certain amount of nutrients from food. Food can simply divide into 2 groups, macro-nutrients and micro-nutrients composition. Both of the groups mentioned do affect the metabolism rate. According to Hulbert and Else, dietary fatty acid will affect the metabolism rate and some of the polyunsaturated fatty acid will increase the metabolism rate (1999). Meanwhile, different kinds of animals have their own unique requirement for macro-nutrients, such as proteins, carbohydrates and fat. Moreover, most of the food intake is driven by achieving the required protein intake.
Animals on a low protein diet will over eat carbohydrates and fat until the protein requirement has been satisfied. If this case occurred in human, obesity will occurred and may have a serious impact to their health. On the other hand, both low energy intake and starvation will decrease the metabolic rates, growth and offspring number and size. In this experiment, we will find out that how does low energy diet affect animal’s metabolism and fitness of the Artemia, which is a species of marine animal by divide those Artemia in to 2 groups and fed by 2 different kind of food.
One of them will be fed by low energy diet while another group of Artemia will be fed with high energy diet. After a certain period, both group of Artemia will be used for this experiment to find out the difference of oxygen consumption and acitivity level. In this experiment, we assume that the both oxygen consumption and activities of low energy intake Artemia will be much lower than the group of high energy intake Artemia. Method
To find out the difference of oxygen consumption and the activity level between 2 groups of Artemia, the low energy intake and the high energy intake, we are required several of equipment, which are a computer with FiBOX3 Fibre-Optic Oxygen Electrode software, a oxygen meter (FiBOX 3, PreSens, Germany) and a temperature-controlled water bath with 25?. In the very beginning, fill the cuvette with water and a known number of Artemia which have a high energy diet from the holding tank by using pipettes.
(This experiment is aimed to use 10 Artemia, however, 7 to 13 Artemias are able to achieve the goal in this experiment. ). Then seal the cuvette under water and make sure no air bubble is inside the cuvette. After that, put the cuvette into the temperature controlled water bath for ten minutes. After 10 minutes, take the cuvette to the oxygen meter to measure the oxygen concentration by holding the end of the end of the fibre-optic cable squarely on to the senor spot from the outside of the cuvette until the concentration has been shown on screen and record it down.
Then return the Artemia to the same incubation bath and repeat this procedure every 5 minutes and measure it for 4 to 5 times. After the process above, we have to find out the total length of the Artemias in the cuvette. To find the total length of the Artemia, use the pipette to move the Artemia out of the cuvette and settle them into a watch glass and measure the length of the Artemias by ruler. At last but not least, put those high energy intake Artemia back into the sink and repeat the experiment instead of those low intake Artemia.
On the other hand, to find the difference of activity of the high and low energy intake Artemia, those Artemia will be tracked by the software named, the Tracker and the Tracker are able to determine the velocity of the Artemia under different treatment for 5 replicates. Result After the experiment, we have recorded 2 sets of oxygen concentration. One of them is from the low energy intake Artemia while the other set of oxygen consumption result are from high energy intake Artemia.
To solve the gross rate of change oxygen concentration in the cuvette, we have to use the oxygen concentration which measured at the first time minus the oxygen concentration which measured at the last time to find out the changes of oxygen concentration and then divide by the time between first and last measurement in hour. In this experiment, we found that the gross rate of change oxygen concentration of high and low energy intake Artemia in 25? 125. 4? mol/L/hr and 116. 7? mol/L/hr in order. Figure 1 shows the difference of chage oxygen consumption between high and low energy intake Artemia.
Fig. 1 Also, the average velocities of the Artemia which under 2 different treatments can be calculated by add up the speed of the Artemia and divided by the number of replicates you have did. The result of this experiment has shown in table 1 and figure 2. The average velocity of high energy intake Artemia is 27. 93ms-1 while the velocity of low energy intake Artemia is 16. 63ms-1. Discussion According to the results from the experiments, we discovered that the oxygen consumption and activity levels of low energy intake Artemia is lower than the high energy intake Artemia.
This proves that different energy diet will affect the oxygen consumption and will decrease theactivity level of that animal. These experiments have proved that our prediction is the same as the result. As we know that low energy diet will reduce the metabolic rates and activity level, so that we predict that the low energy intake level of the Artemia will be much lower than the high energy intake diet Artemia. However, there might have some error occurred in this experiment. For example, air bubble may still exist in the cuvette, the oxygen sensor might have a certain degree of error or the illness of the artemia.
To conclude, the low energy intake Artemia has a lower oxygen consumption rates and activity level since the insufficient nutrition will affect the metabolic rates of Artemia. Reference Gosby, A. K. , Conigrave, A. D. , Lau, N. S. , Iglesias, M. A. , Hall, R. M. , Jebb, S. A. , Brand-Miller, J. , Caterson, I. D, Raubenheimer, D. , Simpson, S. J. (2011) Testing the protein leverage in lean humans: a randomised controlled experimental study. PLoS ONE, 6, e25929 Hulbert, A. J. and Else, P. L. (1999) Membranes as possible pacemakers of metabolism. Journal of Theoretical Biology, 199, 257-274.