Table of contents

1. A Review of General Chemistry5h 5m
2. Molecular Representations1h 14m
3. Acids and Bases2h 46m
4. Alkanes and Cycloalkanes4h 17m
5. Chirality3h 39m
6. Thermodynamics and Kinetics1h 22m
7. Substitution Reactions1h 48m
8. Elimination Reactions2h 30m
9. Alkenes and Alkynes2h 9m
10. Addition Reactions3h 19m
11. Radical Reactions1h 58m
12. Alcohols, Ethers, Epoxides and Thiols2h 42m
13. Alcohols and Carbonyl Compounds2h 17m
14. Synthetic Techniques1h 26m
15. Analytical Techniques:IR, NMR, Mass Spect7h 3m
16. Conjugated Systems6h 13m
17. Ultraviolet Spectroscopy51m
18. Aromaticity2h 34m
19. Reactions of Aromatics: EAS and Beyond5h 1m
20. Phenols55m
21. Aldehydes and Ketones: Nucleophilic Addition4h 56m
22. Carboxylic Acid Derivatives: NAS2h 51m
23. The Chemistry of Thioesters, Phophate Ester and Phosphate Anhydrides1h 10m
24. Enolate Chemistry: Reactions at the Alpha-Carbon1h 53m
25. Condensation Chemistry2h 9m
26. Amines1h 43m
27. Heterocycles2h 0m
28. Carbohydrates5h 53m
29. Amino Acids4h 20m
30. Peptides and Proteins2h 42m
31. Catalysis in Organic Reactions1h 30m
32. Lipids 2h 50m
33. The Organic Chemistry of Metabolic Pathways2h 52m
34. Nucleic Acids1h 32m
35. Transition Metals6h 14m
36. Synthetic Polymers1h 49m

28. Carbohydrates

Monosaccharides - Common Structures

Organic Chemistry

28. Carbohydrates

Monosaccharides - Common Structures

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Multiple Choice

How do the hexoses glucose and galactose differ from one another?

They differ in the number of hydroxyl groups.

They differ in the configuration around the fourth carbon atom.

They differ in the number of carbon atoms in their structure.

They differ in the presence of an aldehyde group.

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Verified step by step guidance

Identify the basic structure of hexoses: Both glucose and galactose are hexoses, meaning they are six-carbon sugars with the molecular formula C₆H₁₂O₆.

Understand the concept of stereoisomers: Glucose and galactose are stereoisomers, which means they have the same molecular formula and sequence of bonded atoms, but differ in the three-dimensional orientations of their atoms.

Focus on the configuration of carbon atoms: In hexoses, the configuration around specific carbon atoms can vary, leading to different stereoisomers.

Examine the fourth carbon atom: The key difference between glucose and galactose is the configuration around the fourth carbon atom (C-4). In glucose, the hydroxyl group (-OH) on C-4 is on the right in a Fischer projection, while in galactose, it is on the left.

Conclude the difference: This difference in the spatial arrangement of the hydroxyl group on the fourth carbon atom is what distinguishes glucose from galactose, not the number of hydroxyl groups, carbon atoms, or the presence of an aldehyde group.