Lab Report Digestion Essay example

2099 Words Jun 3rd, 2013 9 Pages
1.0. INTRODUCTION The primary function of the digestive system is to transfer nutrients, water, and electrolytes from the food consume into the body’s internal environment. The ingested food is essential as an energy source, or fuel, from which the cells can generate ATP to carry out their particular energy-dependent activities such as contraction, transport, synthesis, secretion and even renewal of body tissues. Three primary categories of food ingested by humans which are carbohydrates, proteins and fats emerge as large molecules. These large molecules cannot cross plasma membranes intact to be absorbed from the lumen of the digestive tract into the blood or lymph; hence, it must undergo degradation in size (Sherwood, 2013). This …show more content…
Activity 2
Table 2: Reaction of pepsin in 4 different conditions of tubes Tube | Initial pH | Final pH | Estimated digestion | Explanation | 1.Pepsin,HCl | 3 | 3 | +++ | pH 3 caused from the HCl presence and is optimum for pepsin activity so the amount of protein digestion is highest among others. | 2.Pepsin,water | 5 | 6 | ++ | The pH is 5 which higher than optimum pH of pepsin and pepsin is not in acidic environment. Thus, the amount of protein digestion is lower than tube 1. | 3.HCl,water | 3 | 3 | + | The pH is already optimum for pepsin but there is absence of pepsin. Thus, the amount of protein digestion is the lowest. | 4.Pepsin,NaOH | 14 | 14 | - | Pepsin work best in acidic environment, not alkaline. Thus, there is no protein digestion occurred. |
5.1. Salivary Digestion of Carbohydrates 1. Function of mucin in the mouth:
Acts as lubricant for easier swallowing and protects the mouth lining from abrasion. 2. Indicate the relative amounts of starch and maltose after incubation.

3. What in vivo (in the body) situation is simulated by the conditions in tube 4?
The hydrolysis of carbohydrates by the act of ptyalin is inhibited. 4. Does ptyalin hydrolysis of carbohydrate continue in the

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