This sample essay on Salivary Digestion Lab Report reveals arguments and important aspects of this topic. Read this essay’s introduction, body paragraphs and the conclusion below.
These large molecules cannot cross last 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 degradation process is catcalled by hydrolysis enzymes, which split large molecules into smaller, observable units by combining with water. (Similarity, 2013) The hydrolysis of molecules becomes more effective by the release of specific enzymes that works at optimum pH in different regions of digestive tract.
The three major GIG hormones are gastric from the stomach mucosa, secreting and collection’s (KC) from the duodenal mucosa.
Gastric is released primarily in response to protein in the stomach, and its effects promote digestion of protein. Secreting is released in response to acid in the duodenum, and its effects will neutralize the acid. KC is released in response to fat in the duodenum, and its effects optimize conditions for fat digestion reactions.
(Sherwood, 201 3) Digestion of carbohydrates begins in the mouth (salivary digestion), where the salivary glands (sublunary, subliminal or parroted) will secrete an amylase called fatality that begins the hydrolysis of complex polysaccharides: Plant extraterrestrial glycogen I Amylase
Disaccharide(maltose, sucrose, lactose) I Fatality has an optimum pH of around 6. 8, which is roughly the pH found in the mouth. Protein digestion begins in the stomach (gastric digestion) where the enzyme pepsin splits proteins to shorter polypeptide chains containing amino acids.
Secretion and activation of pepsin occurs as follows: Possession(chief cells) WHQL (parietal cells) I Pepsin I Besides activating possession, HCI provides the stomach a pH of 2, so the pepsin activity works at optimum level. For digestion of fat, pancreatic lipase reaction must be aided with the presence of bile salts as an emulsifier.
Lipase is a water-soluble enzyme, and it is not effective alone to act on the large lipid droplets which are water insoluble. Bile salts emulsify by breaking the fat into smaller droplets so that lipase has a larger surface area for the hydrolysis of fats. The pancreas also aids digestion by secreting sodium bicarbonate. This compound provides a pH of around 7. 8 in the small intestine, which is optimal for the action of the pancreatic enzymes (Similarity, 2013). 2. 0. OBJECTIVES * To examine the action of some of the key digestive enzymes and the factors that can alter their activities. 3. 0.
MATERIALS AND METHODS 3. 1. Materials Test tubes (15 – 20 ml), test tube clamps, measuring cylinders (10 ml), watch glass, pH paper, water baths with test tube racks, hard-boiled egg whites, 1% acetic acid, 1% pancreatic solution in 0. 2% NAACP, 0. 5% starch paste, Logo’s solution, Benedicts solution, 5% pepsin solution, 0. 5% HCI, concentrated HCI, 0. 5% Noah, ice, powdered litmus, litmus paper. 3. 2. Methods 3. 2. 1 . Activity 1 1 . About 10 ml of human saliva (fresh) is collected in a graduated cylinder. 2. A small amount of saliva is placed in a watch glass and a few drops of 1% acetic acid are added.
A precipitate indicated that the present of music (a globetrotting) is indicated by precipitate occurrences. 3. Four test tubes are prepared and labeled as follows: Tube 1 | Tube 2 | Tube? I Tube 4 | 3 ml starch+3 ml waterline’s water bath | 3 ml starch+3 ml saliva inch water bath 3 ml starch (cooled)+3 ml saliva (cooled)’inline bath | 3 ml starch+3 ml saliva+5 drops con Histrionic water bath I 4. Half of each tube’s contents are poured into a new test tube each respectively after the tubes are incubated for 1 hour. One set of tubes is tested for: 5. 1. Starch (Logo’s solution) 5. 1 . 1. Ropes of Logo’s solution is added to each tube. Presence of starch is indicated by dark purple color occurrences. The amount of starch is indicated by the shades of reddish brown. 5. 1. 2. The amount of starch is rated based on the intensity (++4), (+4), or G). 5. 2. Maltose (Benedicts solution) 5. 1. 3. 4 ml of Benedicts solution is added to each tube. The tubes are then placed in a boiling water bath for 2 minutes. 5. 1. 5. The tubes are removed using a clamp and the concentration of maltose is compared using the following scale: red (+++), orange-yellow (++), green (+), blue (-). 3. 2. 2. Activity 1 .
Thin slices of cooked egg white with same size (about 0. 5 cam) are placed in four test tubes. 2. Following solutions are added to the tubes and the pH of each tube is determined: Tube 1 | Tube 2 | Tube 3 | Tube 4 | 5 ml pepsin(5 % solution)+5 ml HCI(O. 5 %) | 5 ml pepsin(5 % solution)+5 ml water | 5 ml HCI(O. 5 ml water | 5 ml pepsin(5 % solution)+5 ml Noah(O. 5 96) | 3. The tubes are allowed to incubate in a teacher bath for 1 hour. The final pH of the solutions is tested and the amount of protein digestion is estimated using a scale of (+++), (++), (+), and (-) by comparing the four tubes. . 0. RESULTS 4. 1. Activity 1 pH of saliva: 6. Presence of Music: present Table 1: Reaction of saliva in 4 different conditions of tubes Tube I Starch I Maltose I Explanation I 1. Water I – 2. Saliva I +++ _ 3. Cooled saliva I ++ I – 4. Saliva,HCI 1+1 – I 4. 2. Activity 2 Table 2: Reaction of pepsin in 4 different conditions of tubes Tube Initial pH Final pH I Estimated digestion Explanation 1 1. Pepsin,HCI 1 31 31 +++ I phi caused from the HCI presence and is optimum for pepsin activity so the amount of protein digestion is highest among others. 1 2. Pepsin,water 1 51 61 ++ I The H 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. HCI,water 1 31 31 +1 The pH is already optimum for pepsin but there is absence of pepsin. Thus, the amount of protein digestion is the lowest. 4. Pepsin,Noah | 14 | 14 – I Pepsin work best in acidic environment, not alkaline. Thus, there is no protein digestion occurred. | 5. 0. POST-LAB QUESTION 5. 1. Salivary Digestion of Carbohydrates 1. Function of music 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. . What in vivo (in the body) situation is simulated by the conditions in tube 4? The hydrolysis of carbohydrates by the act of fatality is inhibited. 4. Does fatality hydrolysis of carbohydrate continue in the stomach? No, the enzyme become inactive soon the food environment is below 4. 0, which the stomach is, by the action of HCI secreted. 5. Where else is amylase secreted in the digestive system? Pancreas, and is called pancreatic amylase. 5. 2. Gastric Digestion of Protein 1 . What in vivo (in the body) situation is simulated by the conditions in tube 4?
Pepsin cannot digest protein in alkaline pH environment. 2. Which other enzyme have major proteolysis activities in the digestive tract? Trapshooting, comprehension and prestidigitation’s 3. A person with chlorinated has defective secretion by the parietal cells. What is the physiological effect of chlorinated in the body? If the HCI is absent in the stomach, protein digestion will be severely impaired, the effect can be associated with pernicious anemia, stomach cancer and pellagra. 4. What is the function of the mucous cells in the gastric pits? i.
Protects the gastric mucosa against mechanical injury through its lubricating properties. Protects the stomach wall from self-digestion due to pepsin iii. Protects gastric lining against acid injury by neutralizing HCI secretions through its alkaline properties without interrupt the function of HCI in lumen. 6. 0. DISCUSSION All food ingested will go along through alimentary canal until it is secreted. Carbohydrates group will undergo digestion first along the way since the enzyme amylase that is responsible to digest the nutrient present in the saliva in the mouth.
Besides having amylase to initiates chemical digestion, saliva also retests oral cavity, such as music. Music is a slippery globetrotting that protects the mouth from friction or erosion whilst undergo mastication (Campbell, et al. , 2008). Salivary amylase helps the carbohydrates digestion by hydrolysis complex polysaccharides to disaccharide and a-limit Dexedrine, that later will be broken down even further by other enzymes into incarcerations, a unit of nutrient that is observable (Sherwood, 2013).
Tube 1 shows slowest reaction because there is no enzyme that can act upon starch or maltose present inside. The reaction will be different if there is implement enzyme present because enzyme functions as catalysts, agents that selectively speed up chemical reaction without being consumed by the reaction (Campbell, et al. , 2008). Hence, tube 1 will react as a control for the results in other tube in Table 1. In tube 2 that containing saliva, there is consistent reaction occur in starch but no in maltose.
It is because saliva contain salivary amylase; enzyme that hydrolysis complex polysaccharides such as starch, consisting polysaccharides amylase (unbranded chain of glucose) and implementation (branched chain of glucose) into smaller polysaccharides (Sherwood, 2013). Since amylase is selectively reacting to polysaccharides, so it does not affect the reaction of maltose, which is a disaccharide. For tube 3 that containing saliva that is cooled, the reaction of starch is slower than tube 2, while the reaction of maltose is same as other previous tube that test on maltose which is no reaction.
Enzyme works best at its optimum temperature that is 37 co which is the normal body temperature (Campbell & Ferret, 2012). Any drops in the temperature will slower the enzymatic reaction like the cooled saliva containing amylase in tube 3. For tube 4, the pH environment is not suitable for amylase to take action. Fatality or amylase has an optimum pH of around 6. 8 (Similarity, 2013), so the acidic environment would inhibit the enzyme, resulted in very slow reaction of starch, and the no reaction in maltose like other tube.
Protein group begins it digestive process in the stomach mantra, which containing enzyme pepsin that responsible in hydroplaning protein to peptide fragment, that soon undergo further breakdown by the act of other enzyme until it become nutrient unit that is observable which is amino acid (Sherwood, 2013). For activity 2, the rating of the results will be based on the intensity of the rupture of albumin textures. Based on Table 2, tube 1 has the most reaction of protein digestion compared to tube 2, 3 and 4.
It is because enzyme pepsin works best at pH of 2 (Campbell & Ferret, 2012), and tube 1 has the nearest pH preferable that is 3, being provided by the present of HCI. It can be observed that the part of the albumin is fragmented. Tube 2 has the second protein digestion because the pH environment is not too acidic for pepsin to act. Hence, there is less fragment resulted at the albumin in tube 2. Since there is no present of pepsin, the digestive process for tube 3 comes in third because there is no enzymatic reaction occurs although the pH reading for tube 3 is near to the optimum pH of pepsin activity.