Cellular Respiration
Give the overall general reaction for cellular respiration. State what eukaryotic cell organelle is involved.
Cellular respiration is the process by which cells convert biochemical energy from nutrients into adenosine triphosphate (ATP). In general, sugar is burned off, or oxidized, into CO2 and H2O. The overall formula is C6H12O6 + 6O2 -> 6CO2 + 6H2O + ~38 ATP (heat). Mitochondria are the eukaryotic cell organelle involved in this process. It is considered the power center of the cell.
Define homoeothermic and endothermic.
Simply stated, homoeothermic refers to a warm-blooded animal. Homoeothermic animals are capable of regulating their own body temperatures internally and independent of their surroundings. Endotherms are similar in that they are also capable of maintaining a sufficient internal core body temperature, regardless of external conditions. Most (not all) homoeothermic animals are also endotherms and use metabolic heat production to keep warm.
What effect did lowering the temperature have on the mouse’s oxygen consumption? What is the effect on cellular respiration? Is this result what you would expect?
The experiment revealed that whether the temperature was 24 C. Or 17 C. The mouse’s oxygen consumption remained the same (15ml). One would normally expect to see a slight increase in oxygen consumption as the temperature dropped. Mice, like other homoeothermic animals, use metabolic processes to increase heat production and stay warm under cooler conditions. This increases the rate of cellular respiration. Homoeothermic animals have automatic physiological reactions to external conditions to maintain core body temperatures.
If you used a poikilothermic animal, such as a frog, for your experiment, what would you have expected to happen to the respiration rate when the environment’s temperature dropped? Poikilothermic animals are mostly cold-blooded animals and unable to maintain constant body temperatures. If the temperature of its general surroundings drops, so does a poikilothermic animal’s rate of respiration. These animals do not have to ability to keep their body temperatures constant. Their body temperatures differ in accordance with the temperature of their surroundings.
How should activity level affect oxygen consumption?
Oxygen is critical in producing the energy needed for physical activity. Respiration and oxygen consumption rates both increase during any form of exercise or physical activity.
According to the data collected, is there a correlation between the mass of the mice and their room temperature respiration rates?
The heavier mice had lower room temperature respiration rates. Larger organisms tend to have higher metabolic rates in general. Metabolic rates are chemical processes that require an expenditure of energy and thus impact respiration rates. It is not surprising to see that the mice weighing 35.9g and 43.2g had lower oxygen consumption rates at room temperature than the mice weighing 30.6g and 32.5g.
How is exercise an example of the Second Law of Thermodynamics?
Under the Second Law of Thermodynamics, energy is always moving from areas of higher concentration to lesser concentration. As it does, it becomes less and less useful. Exercise causes the body to become hotter as more energy is utilized (blood is pumped to areas that need it most) until energy is burned off and fatigue sets in. The energy that was once required for physical activity is eventually depleted.
Describe how cellular respiration and photosynthesis are related.
Cellular respiration involves the intake of oxygen and the release of carbon dioxide. This process provides cells with the energy required to produce energy. Photosynthesis is the process by which plants do the same thing, except it is reversed. Energy from sunlight is used to convert carbon dioxide and water into sugar. This provides the plant with energy. The by-product is oxygen. Together, both photosynthesis and cellular respiration help recycle carbon dioxide and oxygen throughout the environment.
Do plant cells conduct cellular respiration? Why or why not?
Plants, like all living things, undergo processes of cellular respiration. This is because all living things require energy. Energy must be released so that it can be converted into a useful form for cells. The energy stored within the “food” consumed by all living things must be adequately processed to sustain life. Otherwise, the organism will die.
Reference
“Molecular Biology.” Columbia Electronic Encyclopedia, 6Th Edition (2011): 1. Academic Search Premier. Web. 25 Oct. 2012.
