Domanda del libro di testo
Are the α and β forms of the disaccharide lactose enantiomers of each other? Why or why not?
1005
views
Ch.20 Carbohydrates
McMurry8th EditionFundamentals of General, Organic, and Biological ChemistryISBN: 9780134015187
Non è quello che usi tu?Cambia libro di testoScegli un libro di testo diverso
TOC.tableOfContents
- Ch.1 Matter and Measurements27
- Ch.2 Atoms and the Periodic Table20
- Ch.3 Ionic Compounds8
- Ch.4 Molecular Compounds23
- Ch.5 Classification & Balancing of Chemical Reactions12
- Ch.6 Chemical Reactions: Mole and Mass Relationships28
- Ch.7 Chemical Reactions: Energy, Rate and Equilibrium64
- Ch.8 Gases, Liquids and Solids24
- Ch.9 Solutions52
- Ch.10 Acids and Bases25
- Ch.11 Nuclear Chemistry22
- Ch.12 Introduction to Organic Chemistry: Alkanes57
- Ch.13 Alkenes, Alkynes, and Aromatic Compounds47
- Ch.14 Some Compounds with Oxygen, Sulfur, or a Halogen50
- Ch.15 Aldehydes and Ketones45
- Ch.16 Amines42
- Ch.17 Carboxylic Acids and Their Derivatives57
- Ch.18 Amino Acids and Proteins82
- Ch.19 Enzymes and Vitamins63
- Ch.20 Carbohydrates44
- Ch.21 The Generation of Biochemical Energy65
- Ch.22 Carbohydrate Metabolism45
- Ch.23 Lipids42
- Ch.24 Lipid Metabolism33
- Ch.25 Protein and Amino Acid Metabolism24
- Ch.26 Nucleic Acids and Protein Synthesis45
McMurry8th EditionFundamentals of General, Organic, and Biological ChemistryISBN: 9780134015187Non è quello che usi tu?Cambia libro di testo
Capitolo 20, Problema 76
D-Fructose can form a six-membered cyclic hemiacetal as well as the more prevalent five-membered cyclic form. Draw the α isomer of D-fructose in the six-membered ring.
Guida verificata passo dopo passo1
Understand that d-fructose is a ketohexose, meaning it contains six carbons and a ketone functional group. The cyclic forms are created when the ketone group reacts with a hydroxyl group on the molecule to form a hemiacetal.
Identify the six-membered cyclic form of d-fructose. This is called a pyranose form, where the ketone group on carbon 2 reacts with the hydroxyl group on carbon 6 to form a six-membered ring.
Draw the six-membered ring structure. Place oxygen as one of the ring members and arrange the remaining carbons (C2 through C6) and their substituents around the ring. Ensure the ring closure occurs between C2 and C6.
Determine the α isomer. In the α isomer, the hydroxyl group attached to the anomeric carbon (C2 in this case) is positioned *down* (opposite to the CH2OH group attached to C5) in the Haworth projection.
Complete the structure by adding the remaining hydroxyl groups and hydrogen atoms to the appropriate carbons, ensuring the stereochemistry matches that of d-fructose. Verify that the configuration of the chiral centers (C3, C4, and C5) corresponds to the d-fructose configuration.
Risposta video verificata per un problema simile:
Questa soluzione video è stata consigliata dai nostri tutor come utile per risolvere questo problema.
Durata del video:
8mConcetti chiave
Ecco i concetti essenziali che devi comprendere per rispondere correttamente alla domanda.
Cyclic Hemiacetal Formation
Cyclic hemiacetals are formed when a carbonyl group (aldehyde or ketone) reacts with an alcohol, resulting in a ring structure. In the case of d-fructose, the ketone group at C2 reacts with the hydroxyl group on C5, leading to the formation of a six-membered ring. This reaction is crucial for understanding the structural variations of sugars.
Video consigliato:
Percorso guidato
2:55
Cyclic Hemiacetals Concept 2
Anomeric Carbon
The anomeric carbon is the carbon atom in a sugar that was originally part of the carbonyl group and becomes a new chiral center upon cyclization. In d-fructose, the anomeric carbon is C2 in the six-membered ring. The configuration at this carbon determines whether the sugar is in the α or β form, which is essential for distinguishing between different isomers.
Video consigliato:
Percorso guidato
5:36Amino Acid Catabolism: Carbon Atoms Concept 2
Furanose vs. Pyranose Forms
Sugars can exist in different cyclic forms, primarily furanose (five-membered) and pyranose (six-membered) rings. d-Fructose predominantly exists as a furanose, but it can also form a pyranose structure. Understanding these forms is important for grasping the reactivity and biological roles of sugars in various biochemical processes.
Video consigliato:
Percorso guidato
02:35Periodic Table: Elemental Forms (Simplified) Concept 1
Pratica correlata
Domanda del libro di testo
Describe the differences between mono-, di-, and polysaccharides.
1622
views
Domanda del libro di testo
Trehalose, a disaccharide found in the blood of insects, has the following structure. What simple sugars would you obtain on hydrolysis of trehalose? (Hint: Rotate one of the rings in your head or redraw it rotated.)
1117
views
Domanda del libro di testo
Carbohydrates provide 4 kcal per gram. If a person eats 200 g per day of digestible carbohydrates, what percentage of a 2000 kcal daily diet would be digestible carbohydrate?
746
views
Domanda del libro di testo
How are amylose and amylopectin similar to each other, and how are they different from each other?
595
views
Domanda del libro di testo
Name a naturally occurring carbohydrate and its source for each type of carbohydrate listed in Problem 20.83.
666
views