Lab KEY

In order for respiration to occur, gases are transported in the blood. 3. Explain in your own words the significance of a) pH in respiration & homeostasis In order for respiration to occur, gases are transported in the blood. Carbon dioxide is mostly carried in the blood with the help of bicarbonate ions and carbonic acid. The dissociation and reformation of carbonic acid (crucial buffer) helps maintain the blood’s pH of 7.4 despite the influx / outflux of CO2 during respiration. Also pH affects the ability of hemoglobin to stay attached to oxygen. pH is lower in body tissues which facilitates the release of Oxygen and a higher pH in the lungs facilitates the attachment of oxygen to hemoglobin for transport

The main buffer in the blood is a combo of carbonic acid and the bicarbonate ion. It works by a series of reactions that involve the dissociation and reformation of Carbonic Acid. When H+ is added to the blood H2CO3 is formed. When OH- is added to the blood H2C03 breaks apart to form HCO3- and H20) Buffers are extremely important in the human body to maintain homeostasis (to keep the internal environment constant). Buffers have the ability to take up excess H+ ions or OH- ions which helps maintain the blood pH at a constant pH of 7.4

2. Explain in your own words the significance of b) pH in Digestion An acidic pH helps with the breakdown of some food in the stomach during digestion. However most importantly a low pH activates required enzymes. The pH of the stomach must be acidic in order for the enzyme pepsin to function. Pepsin is required to break down proteins during digestion and will not do so if the pH is not acidic.

c) Acid deposition & Ecological Impacts 2. Explain in your own words the significance of c) Acid deposition & Ecological Impacts Normally rain water has a pH of about 5.6. However, an increase in the CO2 being released in the atmosphere due to the burning of fossil fuels as resulted in acid deposition. Aluminum leaches from the soil, mercury deposits become toxic and forests can die out due to lack of nutrients and increased aluminum from the lowered pH of acid buildup from deposition (rain). As a result of changes in pH ecosystems are adversely affected and biodiversity can drastically decrease as some species are not able to survive the pH changes.