10/22/2012
Common Substances in Living Systems
Water is the most abundant substance in living cells; approximately 60% to 80%. Water molecules are polar, it determines why ionic bonded molecules dissociate in water. Hydrolysis is when water breaks down larger molecules of food during digestion. Water is considered to be a universal solvent. Water is also important for the transport of materials like hormones and enzymes within the blood plasma. Water helps to stabilize body temperature because it absorbs and releases high levels of heat before its temperature changes. Water serves as a shock absorber and finally it is a base for all body lubricants in system,
The ammonia molecule (NHȝ) comes from the decomposition of proteins …show more content…
It is the body’s attempt to maintain a constant internal environment. Maintaining a stable internal environment requires constant monitoring and adjustments as conditions change. Homeostasis is essential to survival, when it is maintained, the body is healthy. Examples of homeostasis in the body includes body temperature, blood sugar levels, heart rate, and the fluid environment of the cell
The reason our body can adjust to temperature changes is because there is a set point for our body temperature. This set point of course is 98.6°F. If the temperature deviates dramatically from this point, the hypothalamus of the brain detects to either reduce your body temperature- by sweating for example- or increase your body temperature by shivering. Our body must constantly monitor itself to correct any major deviations in homeostasis. The responses relies on feedback loops: negative feedback and positive feedback. Most of the homeostatic responses in our body involve negative feedback loop. Positive feedback loops is an increase in function in response to a stimulus. So while negative feedback loops work to minimize change, positive feedback loops increase change. Our organ systems help control the internal environment of the body and cells so that it remains constant. If homeostasis is not maintained, the body will experience disease and eventually