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

34. Nucleic Acids

DNA Double Helix

Organic Chemistry

34. Nucleic Acids

DNA Double Helix

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Multiple Choice

What type of bonds connect the pairs of strands that make up the double helix of DNA?

Covalent bonds

Hydrogen bonds

Ionic bonds

Metallic bonds

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Verified step by step guidance

Understand the structure of DNA: DNA is composed of two strands that form a double helix. Each strand is made up of nucleotides, which include a sugar, a phosphate group, and a nitrogenous base.

Identify the types of bonds present in DNA: Within each strand, nucleotides are connected by covalent bonds, specifically phosphodiester bonds, between the sugar of one nucleotide and the phosphate of the next.

Focus on the interaction between the two strands: The two strands of the DNA double helix are held together by interactions between the nitrogenous bases.

Recognize the specific type of bond: The nitrogenous bases on one strand form hydrogen bonds with complementary bases on the opposite strand. Adenine pairs with thymine via two hydrogen bonds, and cytosine pairs with guanine via three hydrogen bonds.

Conclude the type of bond: The pairs of strands in the DNA double helix are connected by hydrogen bonds, which provide stability to the structure while allowing the strands to separate during processes like replication and transcription.