An adult takes roughly 12 breaths each minute, inhalingapproximately 500mL with each breath. Oxygen and carbon dioxide areexchanged in the lungs. The amount of nitrogen exhaled equals theamount inhaled, and the mole fraction of nitrogen in the exhaledair is 0.75. The exhaled air is saturated with water vapor at bodytemperature, 37

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In respiration, air is inhaled into the lungs, which provide a large surface area for transport of oxygen, carbon dioxide, and water to or from the blood. The transported oxygen is delivered to body cells where it oxidizes glucose and fats from food to produce carbon dioxide, water, and thermal energy. The carbon dioxide and water are transported from the cells to the blood and back to the lungs, from which they are exhaled. The exhaled gas is at body temperature and saturated with water, some produced in the glucose and fat oxidation and some additionally drawn from moist lung tissue. Other water-containing streamsâ food, water, perspiration, and excreted waste streamsâmaintain the bodyâs level of hydration.

Suppose an individual inhales air at 20Â°C and 20% relative humidity, and 25% of the inhaled oxygen is consumed in the glucose oxidation reaction. (Under certain conditions, it is reasonable to neglect the oxidation of fats.) A flowchart of the respirationâmetabolism process is shown below. The water in the exhaled gas equals the inhaled water plus the water produced by glucose oxidation plus additional water drawn from the lungs. Qm represents only the heat transferred to or from the body as a consequence of the phenomena just described; not shown are heat and work transferred due to other bodily processes.

(a) Assume a basis of 1 mol bone-dry air (plus the water that goes with it) inhaled at 20Â°C. Draw and fully label a flowchart of the metabolic process, considering only breathing and glucose oxidation as components of the process. You donât need to label the streams between the two units, since this problem will not require determining their masses or compositions. Do a degree-of-freedom analysis of the overall system.

(b) Suppose all of the water and CO2 produced from the glucose oxidation are transported to the lungs and exhaled, and calculate the masses of all components of all labeled streams.

(c) If the individual inhales an average of 500 mL of air per breath and takes 12 breaths per minute, how much water (fluid ounces) must she drink per day to make up for the water she loses by breathing?

(d) Returning to the original basis, estimate the heat (kJ) transferred to or from the body as a consequence of breathing and glucose oxidation, assuming that the glucose is oxidized at 37Â°C and at that temperature ÎHc= -2816 kJ/mol:

On average , 0.207 liter of oxygen at 760 torr are required for every Calorie of energy released by the food oxidation in the body. The amount of energy consumed by the person depends on person weight and build. However, the amount of energy per unit area is the same for most people. This is known as metabolic rate, which depends on the type of activity only. For instance, metabolic rate of resting is 40 space fraction numerator C a l over denominator m squared space h r end fraction , standing 60 space fraction numerator C a l over denominator m squared space h r end fraction , walking with the speed of 3 mi/hr 140 space fraction numerator C a l over denominator m squared space h r end fraction , etc. Surface area of a person can be accurately evaluated by empirical formula: A r e a space left square bracket m squared right square bracket space equals 0.202 space cross times space M to the power of 0.425 end exponent space cross times space H to the power of 0.725 end exponent , where M is the person's mass in Kilograms and H is the height in meters. You need to predict breathing rate (amount breaths per minute) for a walking 85-Kg person 1.75 m tall taking into consideration that: 1. The lungs are not fully emptied and filled with each breath. In fact, the volume of the lungs is about 6 liter, and at rest only 0.5 liter is exchanged during each breath. This amount is doubled while walking. 2. The content of nitrogen, oxygen and carbon dioxide correspondingly 79.03% ; 20.93% ; 0.04% in inspired air and 79.4% ; 16.1% 4.5% in expired air. Submit numeric value of your answer only