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

1. A Review of General Chemistry

Intro to Organic Chemistry

Organic Chemistry

1. A Review of General Chemistry

Intro to Organic Chemistry

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Multiple Choice

In the context of organic chemistry, where does the energy in most ecosystems originate?

From the sun through photosynthesis

From chemical reactions in the atmosphere

From geothermal sources

From the breakdown of organic molecules

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Verified step by step guidance

Understand that in most ecosystems, energy primarily originates from the sun. This is because the sun provides the light energy necessary for photosynthesis, a process carried out by plants, algae, and some bacteria.

Recognize that photosynthesis is the process by which these organisms convert light energy into chemical energy stored in glucose, a simple sugar. The general equation for photosynthesis can be represented as:

6 CO 2 + 6 H 2 O \to C 6 H 12 O 6 + 6 O 2

Consider the role of photosynthesis in the ecosystem: it not only provides energy for the plants themselves but also forms the base of the food chain. Herbivores consume plants to obtain energy, and carnivores, in turn, consume herbivores.

Evaluate the other options: Chemical reactions in the atmosphere and geothermal sources do contribute energy, but they are not the primary sources for most ecosystems. The breakdown of organic molecules releases energy, but this energy originally comes from the sun, captured through photosynthesis.

Conclude that the primary source of energy in most ecosystems is the sun, as it initiates the process of photosynthesis, which is fundamental to the energy flow in ecosystems.