Human saliva contains the enzyme α-amylase which hydrolyzes polysaccharide acetal linkages. A soda cracker (containing starch) was carefully ground; the crumbs were distributed evenly between two test tubes. The first test tube contained only water, while the second contained a 1% solution of α-amylase. Both mixtures were heated to 35°C for 10 minutes and filtered. The filtrates were tested with iodine solution and Benedict’s solution. Use the following results to answer the questions below. Mixture Iodine test Benedict’s Test cracker in water dark blue blue cracker in water and α-amylase red red-orange precipitate a. Was the starch from the cracker/water mixture hydrolyzed? Was the starch from the cracker in the 1% α-amylase solution hydrolyzed? b. Which cracker contained reducing sugars?

Human saliva contains the enzyme α-amylase which hydrolyzes polysaccharide acetal linkages. A soda cracker (containing starch) was carefully ground; the crumbs were distributed evenly between two test tubes. The first test tube contained only water, while the second contained a 1% solution of α-amylase. Both mixtures were heated to 35°C for 10 minutes and filtered. The filtrates were tested with iodine solution and Benedict’s solution. Use the following results to answer the questions below. Mixture Iodine test Benedict’s Test cracker in water dark blue blue cracker in water and α-amylase red red-orange precipitate a. Was the starch from the cracker/water mixture hydrolyzed? Was the starch from the cracker in the 1% α-amylase solution hydrolyzed? b. Which cracker contained reducing sugars?

Chemistry: The Molecular Science

5th Edition

ISBN:9781285199047

Author:John W. Moore, Conrad L. Stanitski

Publisher:John W. Moore, Conrad L. Stanitski

Chapter10: Fuels, Organic Chemicals, And Polymers

Section: Chapter Questions

Problem 119QRT

See similar textbooks

Similar questions

A 1 mL sample of glycogen was calculated to contain 35 µmol (micromole) glucose. To 1 mL of this sample was added 2 mL of 2 M HCL. It was then hydrolysed by boiling the solution for 15 minutes. After boiling the hydrolysate was cooled and made up with H2O to a final volume of exactly 10 mL. The glucose was measured in this solution and found to have a concentration of 570 µg/mL (microgram/milliliter). i) Calculate the mass (mg) of glucose in the 10 mL of hydrolysate. As the 1mL of glycogen sample was made up to a final volume of 10 mL, this mass of glucose was produced by the hydrolysis of the original 1 mL glycogen sample. ii) Calculate the amount (µmol) of glucose produced by the hydrolysis of the glycogen sample. iii) Calculate the purity of the glycogen used in the sample as % Purity = (moles of measured glucose/ moles of calculated glucose in glycogen) *100 iv) state your answer in a complete sentence.
A 1 mL sample of glycogen was calculated to contain 21 µmol (micromole) glucose. To 1 mL of this sample was added 2 mL of 2 M HCl. It was then hydrolysed by boiling the solution for 15 minutes. After boiling the hydrolysate was cooled and made up with H2O to a final volume of exactly 10 mL. The glucose was measured in this solution and found to have a concentration of 340 µg/mL (microgram/milliliter). i) Calculate the mass (mg) of glucose in the 10 mL of hydrolysate. As the 1 mL of glycogen sample was made up to a final volume of 10 mL, this mass of glucose was produced by the hydrolysis of the original 1 mL glycogen sample. ii) Calculate the amount (µmol) of glucose produced by the hydrolysis of the glycogen sample. iii) Calculate the purity of the glycogen used in the sample as % Purity = (moles of measured glucose/ moles of calculated glucose in glycogen) *100 iv) state your answer in a complete sentence. Show your working out such that the marker can easily understand it.…
5.0 mL of 1-butanol was mixed with 10 mL of HCl. The reaction was put on an ice bath and 4 mL of concentrated sulfuric acid was added. This mixture was refluxed for 45 min and then the product was co-distilled with water using a simple distillation apparatus. Water and the product are immiscible. 1-butanol has a molar mass of 74.12 g/mol, a density of 0.810 g/mL, and a boiling point of 118 C. The product has a molar mass of 92.57 g/mol, a density of 0.880 g/mL, and a boiling point of 78 C. What is the nucleophile in this reaction? What is the role of H2SO4 in this reaction? Calculate the theoretical yield for this reaction. Give your answer in grams. Select the following statements that can be said about the reaction shown.
Oral rehydration salts are stated to contain the following components: Sodium Chloride 3.5g Potassium Chloride 1.5g Sodium Citrate 2.9g Anhydrous Glucose 20.0g 8.342 g of oral rehydration salts are dissolved in 500 ml of water. 5 ml of the solution is diluted to 100 ml and then 5 ml is taken from the diluted sample and is diluted to 100 ml. The sodium content of the sample is then determined by flame photometry. The sodium salts used to prepare the mixture were: Trisodium citrate hydrate (C6H5Na3O7, 2H2O) MW 294.1 and sodium chloride (NaCl) NW 58.5. Atomic weight of Na = 23. The content of Na in the diluted sample was determined to be 0.3210 mg/100 ml. Determine the % of stated content of Na in the sample.
Oral rehydration salts are stated to contain the following components: Sodium Chloride 3.5g Potassium Chloride 1.5g Sodium Citrate 2.9g Anhydrous Glucose 20.0g 8.342 g of oral rehydration salts are dissolved in 500 ml of water. 5 ml of the solution is diluted to 100 ml and then 5 ml is taken from the diluted sample and is diluted to 100 ml. The sodium content of the sample is then determined by flame photometry. The sodium salts used to prepare the mixture were: Trisodium citrate hydrate (C6H5Na3O7, 2H2O) MW 294.1 and sodium chloride (NaCl) NW 58.5. Atomic weight of Na = 23. The content of Na in the diluted sample was determined to be 0.3210 mg/100 ml. Determine the % of stated content of Na in the sample. The stated should be 104.5, how??
A phamacist reconstituted a vial of 750 mg Cefuroxime Sodium Powder for Injection with 6mL of sterile water for injection. The reconstituted solution was dark amber-colored solution. The package insert states that solution colors range from clear to yellow depending on concentration, diluent, and storage conditions. The pharmacist was then hesitant to give the patient the solution due to its unusual dark color. Five portions were taken from a batch of cefuroxime sodium. Prior to testing in the instrument, each part was subjected to one of the following conditions: Conditions Specifications Temperature Portion 1: 8°C ± 2°C Portion 2: 30°C ± 2°C Portion 3: 40°C ± 2°C Light Portion 4: Kept in the dark Portion 5: Exposed to direct sunlight a. Which form of the product – the powder for injection, the reconstituted product, or both – will you subject to the following conditions and why? b. Will you also expose the reference standard of cefuroxime sodium to the same…
In the phosphate analysis of a wastewater sample, 30.00 mL of the original sample was taken and diluted with 120.00 mL deionized water. The diluted sample was found to have a phosphate content of 25.5 ppm. What is the phosphate content (in ppm) of the original wastewater sample?
A student performs a crystallization on an impure sample of biphenyl. The sample weighs 0.5 g and contains about 5% impurity. Based on his knowledge of solubility, the student decides to use benzene as the solvent. After crystallization, the crystals are dried and the nal weight is found to be 0.02 g. Assume that all steps in the crystallization are performed correctly, there are no spills, and the student lost very little solid on any glassware or in any of the transfers. Why is the recovery so low?
5.20 g of tea leaves were used for the extraction of caffeine in a laboratory experiment, If the mass of crude caffeine obtained and the mass of pure caffeine recovered after recrystallization are 0.166 g and 0.082 g respectively, what is the percentage yield of pure caffeine from the tea leaves? O 2.10% O 2.30% O 1.58% O 3.62%
(d) A sample contains a mixture of ammonium carbonate (NH4)2CO3, sodium carbonate Na2CO3, and sodium chloride NaCl. Thermogravimetric analysis indicates that a 0.0965-g portion of this sample loses 0.0574 g over a temperature range of 50-75 oC and then loses another 0.0124 g at 800 oC.(i) What causes the weight loss at 50-75 oC? (ii) What species will remain after being heated to 800 oC? (iii) What is the composition of the original sample? Given: Atomic masses: H = 1.008; C = 12.011; N = 14.007; Na = 22.99; O = 15.999;Cl = 35.45.
A sample (50 mL) of a bottled water was added to a 100 mL volumetric flask and then diluted to the mark. From this stock solution, 50 mL was taken, added to a 100 mL volumetric flask and diluted to the mark. Final concentration of the serial dilution: 587.7161ppm. 1. what is the concentration in the original bottle (ppm)
Please answer questions 4a, 4b, and 4c. The questions are provided in the attached image. Thank you.