Using the Law of Mass Action, the equilibrium constant for the dissociation reaction of water can be written as: A p-Scale is defined to express small values:
Many people today are interested in exercise as a way of improving their health and physical abilities. But there is also concern that too much exercise, or exercise that is not appropriate for certain individuals, may actually do more harm than good. Exercise has many short-term acute and long-term effects that the body must be capable of handling for the exercise to be beneficial.
Some of the major acute effects of exercising are shown in Figure 1. When we exercise, our heart rate, systolic blood pressure, and cardiac output the amount of blood pumped per heart beat all increase.
Blood flow to the heart, the muscles, and the skin increase. We breathe faster and deeper to supply the oxygen required by this increased metabolism. Eventually, with strenuous exercise, our body's metabolism exceeds the oxygen supply and begins to use alternate biochemical processes that do not require oxygen.
These processes generate lactic acid, which enters the blood stream. As we develop a long-term habit of exercise, our cardiac output and lung capacity increase, even when we are at rest, so that we can exercise longer and harder than before. Over time, the amount of muscle in the body increases, and fat is burned as its energy is needed to help fuel the body's increased metabolism.
Figure 1 This figure highlights some of the major acute short-term effects on the body during exercise. Dialysis in the Kidneys " you learned about the daily maintenance required in the blood for normal everyday activities such as eating, sleeping, and studying.
Now, we turn our attention to the chemical and physiological concepts that explain how the body copes with the stress of exercise. As we shall see, many of the same processes that work to maintain the blood's chemistry under normal conditions are involved in blood-chemistry maintenance during exercise, as well.
During exercise, the muscles use up oxygen as they convert chemical energy in glucose to mechanical energy. This O2 comes from hemoglobin in the blood. These chemical changes, unless offset by other physiological functions, cause the pH of the blood to drop.
If the pH of the body gets too low below 7. This can be very serious, because many of the chemical reactions that occur in the body, especially those involving proteins, are pH-dependent. Ideally, the pH of the blood should be maintained at 7. If the pH drops below 6.
Fortunately, we have buffers in the blood to protect against large changes in pH. This external fluid, in turn, exchanges chemicals with the blood being pumped throughout the body.
A dominant mode of exchange between these fluids cellular fluid, external fluid, and blood is diffusion through membrane channels, due to a concentration gradient associated with the contents of the fluids.
Recall your experience with concentration gradients in the "Membranes, Proteins, and Dialysis" experiment. Hence, the chemical composition of the blood and therefore of the external fluid is extremely important for the cell. As mentioned above, maintaining the proper pH is critical for the chemical reactions that occur in the body.
In order to maintain the proper chemical composition inside the cells, the chemical composition of the fluids outside the cells must be kept relatively constant. This constancy is known in biology as homeostasis.
Figure 2 This is a schematic diagram showing the flow of species across membranes between the cells, the extracellular fluid, and the blood in the capillaries. The body has a wide array of mechanisms to maintain homeostasis in the blood and extracellular fluid.
The most important way that the pH of the blood is kept relatively constant is by buffers dissolved in the blood. Other organs help enhance the homeostatic function of the buffers.
The kidneys help remove excess chemicals from the blood, as discussed in the Kidney Dialysis tutorial. Acidosis that results from failure of the kidneys to perform this excretory function is known as metabolic acidosis. However, excretion by the kidneys is a relatively slow process, and may take too long to prevent acute acidosis resulting from a sudden decrease in pH e.
The lungs provide a faster way to help control the pH of the blood. The increased-breathing response to exercise helps to counteract the pH-lowering effects of exercise by removing CO2, a component of the principal pH buffer in the blood.
Acidosis that results from failure of the lungs to eliminate CO2 as fast as it is produced is known as respiratory acidosis. A Quantitative View The kidneys and the lungs work together to help maintain a blood pH of 7.It's a good thing, then, that human blood contains a buffer of carbonic acid, H 2 CO 3, and sodium bicarbonate, NaHCO 3.
This buffer regulates drastic shifts in the pH of our blood. This buffer regulates drastic shifts in the pH of our blood. Buffers Keep The Balance Lab I. Purpose Our purpose in this lab was to investigate what buffers are made of, and how they maintain the delicate pH balance needed for life and health.
This lab 80%(5).
Other buffers perform a more minor role than the carbonic-acid-bicarbonate buffer in regulating the pH of the blood. The phosphate buffer consists of phosphoric acid (H 3 PO 4) in equilibrium with dihydrogen phosphate ion (H 2 PO 4 -) and H +. Chemistry Lab Jamie Magrill B Abstract The carbonic acid/bicarbonate buffers in blood may be modeled by a phosphate buffer system due to a decomposition factor in the former set of buffers.
Because CO 2 is an important component of the blood buffer, its regulation in the body, as well as that of O 2, is extremely important. The effect of this can be important when the human body is subjected to strenuous conditions. View Notes - Buffer Lab from CHEMISTRY AP Chemist at Rochester High School.
Buffers Keep The Balance Lab I. Purpose Our purpose in this lab was to investigate what buffers are made of, and how.