Concept explainers
Interpretation:
The structure of lactose sugar based on the given experimental evidences is to be shown.
Concept introduction:
舧 Chair conformations: It is the most stable conformation, which accurately shows the spatial arrangement of atoms.
舧 Equatorial bonds are parallel to the average plane of the ring, while axial bonds are perpendicular to the average plane of the ring.
舧 The conformation having bonds at the equatorial positions are more stable than those with bonds at the axial position.
舧 On flipping the cyclohexane ring, axial bonds become equatorial bonds and equatorial bonds becomes axial bond.
舧 Bulkier group acquires equatorial positions to form stable conformer due to steric factors.
舧 The most stable configuration of aldopyranoses is when the
舧 Stereochemistry: The equatorial orientation refers to the spatial arrangement of
舧 The anomeric effect is lowest for sugars with equatorial orientation, which results in lower energetic state, and consequently this type of orientation confers higher stability.
舧 The anomeric effect is highest for sugars with axial orientation, which results in higher energetic state, and consequently this type of orientation confers lower stability.
舧 A carbohydrate is a
舧
舧 Carbohydrates are oxidized by
舧 Aldaric acids are carbohydrates having two carboxylic acids. They are formed due to oxidation reaction of aldoses with dilute
舧 Monosaccharides containing six carbon atoms and an aldehyde group are called aldohexoses.
舧 Alditols are compounds produced from aldoses or ketoses on reduction with certain reagents such as sodium borohydride (
舧
舧 Compounds formed by the reaction of reducing sugars with excess of phenyl hydrazine are called osazones. Osazones are products of oxidation and are produced by all reducing sugars.
舧
舧 Fischer projection is a way of representing the structural formulae of compounds through cross formulation of their open chain structures.
舧 Bromine water is an effective reagent that selectively oxidizes the
舧 Lactose is a disaccharide carbohydrate present in milk (mammary glands) of the mammals. It has a reducing nature and undergoes hydrolysis to yield
舧 The aldehyde group of an aldose reacts with three moles of phenylhydrazine to produce phenylosazone at
舧 The monosaccharides with five or more carbons atoms form cyclic structures in aqueous solution, and they can form two cyclic stereoisomers from each straight-chain monosaccharide, known as anomers. In aqueous solution, the two anomers and the straight-chain structure of a monosaccharide form an equilibrium mixture through the process of mutarotation.
Want to see the full answer?
Check out a sample textbook solutionChapter 22 Solutions
Organic Chemistry
- 21-90 To what extent do lipids and carbohydrates play structural roles in living organisms? Do these roles differ in plants and in animals?arrow_forward22-62 Distinguish between intermolecular and intramolecular hydrogen bonding between backbone groups. Where in protein structures do you find one, and where do you find the other?arrow_forwardThe sweetness of honey gradually decreases at a high temperature. Also, high-fructose corn syrup (a commercial product in which much of the glucose in corn syrup is converted to fructose) is used for sweetening cold but not hot drinks. What chemical property of fructose could account for both of these observations? The melting point of fructose goes down at higher temperatures. Fructose has an open-chain form in addition to the cyclic forms. Increasing the temperature prevents fructose from cyclizing, decreasing its sweetness. O Fructose cyclizes to either the pyranose or the furanose structure. Increasing the temperature shifts the equilibrium in the direction of the less sweet furanose form. O Fructose can exist as either an aldose or ketose. Higher temperatures promote the conversion of the sweeter ketose form to the less sweet aldose form.arrow_forward
- One of the cyclic forms of D-ribose has the structure CH2OH OH ОНОН (a) How many anomeric carbon atoms are present in this structure? (b) How many hemiacetal carbon atoms are present in this structure?arrow_forwardHO HO ܦܐܐ ܒܐܠܥܐ HO HO OH OH HO- OH HO HO- OH Barley grain is used in the production of beer. This grain contains many polysaccharides which are hydrolyzed into sugars for yeast fermentation. Beta-glucans are polymers of glucose units. Many of these polysaccharides have a lot of branching. Identify the glycosidic linkages in this beta-glucan polysaccharide. OH OH OH HO Question 1.b of 45 HO OH A) a-1,4-linkages B) B-1,4-linkages C) a mix of a-1,3 and a-1,4-linkages D) a mix of B-1,3 and ß-1,4-linkages E) a mix of a-1,3 and ß-1,4-linkages Submit +arrow_forwardGive the amino acid sequence of a hexapeptide that contains the amino acids Ala, Val, Ser, Ile, Gly, Tyr, and forms the following fragments when partially hydrolyzed with HCl: Gly–Ile–Val, Ala–Ser–Gly, and Tyr–Ala.arrow_forward
- Describe the glycosidic bond in this repeating disaccharide unitarrow_forwardKindly answer question i & iiarrow_forwardThe standard free energy change (ΔG°') for hydrolysis of fructose-l,6-bisphosphate (FBP) to fructose-6-phosphate (F-6-P) and Pi is -16.7 kJ/mol: FBP + H2O → Fructose-6-P + Pi The standard free energy change (ΔG°') for ATP hydrolysis is -30.5 kJ/mol: ATP + H2O → ADP + Pi a What is the standard free energy change for the phosphofructokinase reaction: ATP + Fructose-6-phosphate → ADP + FBP ΔG°' = -13.8 kJ/mol b What is the equilibrium constant for this reaction at 25.0 °C? K'eq =arrow_forward
- (a) What is the empirical formula of cellulose? (b) Whatis the monomer that forms the basis of the cellulose polymer?(c) What bond connects the monomer units in cellulose:amide, acid, ether, ester, or alcohol?arrow_forwardPlease don't provide handwritten solution ....arrow_forwardIt is well known that humans are able to digest amylose, but not cellulose. What structural features might be responsible this observation?arrow_forward
- Introduction to General, Organic and BiochemistryChemistryISBN:9781285869759Author:Frederick A. Bettelheim, William H. Brown, Mary K. Campbell, Shawn O. Farrell, Omar TorresPublisher:Cengage LearningOrganic ChemistryChemistryISBN:9781305580350Author:William H. Brown, Brent L. Iverson, Eric Anslyn, Christopher S. FootePublisher:Cengage Learning
- Chemistry: Matter and ChangeChemistryISBN:9780078746376Author:Dinah Zike, Laurel Dingrando, Nicholas Hainen, Cheryl WistromPublisher:Glencoe/McGraw-Hill School Pub CoChemistry for Today: General, Organic, and Bioche...ChemistryISBN:9781305960060Author:Spencer L. Seager, Michael R. Slabaugh, Maren S. HansenPublisher:Cengage LearningGeneral, Organic, and Biological ChemistryChemistryISBN:9781285853918Author:H. Stephen StokerPublisher:Cengage Learning