Fall 2016 DIO 204 ANATOMY&PHYSIOLOGY; Chemical dign be absorbed into the blood.
ID: 3524610 • Letter: F
Question
Fall 2016 DIO 204 ANATOMY&PHYSIOLOGY; Chemical dign be absorbed into the blood. In this experiment, you will investigate the chemical breakdown of a Rpid and the e Materials: Work in pairs nvolves the enzymatic breaking of chemical bonds in large macromoleoules to fornm test tube rack adhesive labels and pen smal disposable pipettes ice bath in fridge test tube holder : 37C water bath at center bencpots . solutions cream+litmus (a pH indicator) * water biWe salts . ipase boiled lipase Note: The cream has the litmus pH indicator already added. At a basic pH, the litmus is purple. The litmus is red at an acidic pH. Procedure: NOTE: safety goggles are required for this experiment 1. Working in pairs, label test tubes 1-7 using adhesive labels and a pen; place test tubes in rack in numerical order 2. Dispense solutions found at the center bench. Dispense 3 ml of all solutions; 3 ml is approximately one full dropper using the disposable plastic pipettes. 3. Tube 1: add 3 ml of water and 3 ml of lipase: swirl gently to mix 4. Tube 2: add 3 ml of cream (with pH indicator added) and 3 ml of water, swirl gently to mix. 5. Tube 3: add 3 ml of cream (with pH indicator added) and 3 ml of boiled lipase; swirl gently to mix. 6. Tube 4: add 3 ml of cream (with pH indicator added) and 3 ml of lipase; swirl gently to mix. 7. Tube 5: add 3 ml of cream (with pH indicator added). 3 ml of lipase, and a pinch of bile salts; swirl gently to 8. Record the starting color of tubes 2-5 and write the information in the data table below. (see note above about color of pH indicator) 9. Place all tubes above (tubes 1-5) in a 37 degree C water bath for one hour. 10. Tube 6: add 3 ml of cream (with pH indicator added) 11. Tube 7: add 3 ml of cream (with pH indicator added) 12. Immediately place tubes 6 and 7 in a 0 degree C ice water tray 13. Add 3 ml of lipase to tube 6 without removing the tube from the water bath. Swirl gently to mix. 14 Add 3 ml of lipase and a pinch of bile salts to tube 7 without removing the tube from the water bath. Swirl gentiy to mix. starting color of tubes 6 and 7; write the information in the data table below (see note above about color of pH indicator) 16. Place the ice water bath in the refrigerator for one hour. the end of one hour, record the color of tubes 2-7: record the information in the data table.Explanation / Answer
1] Lipase digestion occurred in tubes 4 and 5.
We can say this because the colour of the mixture changed from purple to red. This was due to pH indicator which showed red colour as lipid was digested into fatty acids and glycerols.
2] Tube 5 had the most favourable conditions for lipid digestion because it contained lipase as well as bile salts. Bile salts help in emulsification of fats and enzymes can act faster and more effectively on emulsified fat molecules.
3] Triglycerol + water lipase > glycerol + fatty acid
Here, the substrate is Triglycerol and products are glycerol and fatty acid.
The enzyme is lipase.
4] A pH indicator changes colour in acidic and basic mediums. As fats are digested, they break down into molecules of fatty acids and glycerols. Thus, a change in the colour of pH indicator signifies the change in the medium and this, in turn, points to the digestion of lipids.
5] Tube 2- because water cannot digest lipids
Tube 3- because boiling will denature the enzyme lipase and it will no longer be effective in digesting lipids.
Tubes 6 and 7 -- because these tubes were kept in ice trays which lowered the temperature below that required for the enzyme to act on the substrate. So, enzyme activity was arrested and the digestion of lipid could not take place.
6] The action of lipase is optimum between 35 to 40-degree Celsius. At about 40-degrees the enzyme action is maximum because the collision rate between the enzyme and the substrate molecule is the fastest. At higher temperatures, the enzyme is denatured while at lower temperatures, the rate of reaction is very slow.
7] Enzymes are complex protein molecules and proteins are denatured on heating. So, when the enzyme is boiled before adding it to the lipid in the test tube, it is ineffective and is not able to digest the lipid.
8] When the test tubes are placed in the refrigerator, the temperature is lowered below the optimal temperature for enzyme activity. Hence, as a result of this lowered temperature, either the enzyme will act very slowly or will not act at all.
9] The chemical digestion of lipid occurs in the small intestine under the action of bile juice secreted by the liver and the enzyme lipase contained in the pancreatic juice secreted by the pancreas.
10] Lipase is produced by the pancreas and the walls of the small intestine.
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