Table of contents

1. Matter and Measurements4h 31m
2. Atoms and the Periodic Table5h 23m
3. Ionic Compounds2h 18m
4. Molecular Compounds2h 18m
5. Classification & Balancing of Chemical Reactions3h 17m
6. Chemical Reactions & Quantities2h 27m
7. Energy, Rate and Equilibrium3h 46m
8. Gases, Liquids and Solids3h 25m
9. Solutions4h 10m
10. Acids and Bases3h 29m
11. Nuclear Chemistry56m
BONUS: Lab Techniques and Procedures1h 38m
BONUS: Mathematical Operations and Functions47m
12. Introduction to Organic Chemistry1h 34m
13. Alkenes, Alkynes, and Aromatic Compounds2h 12m
14. Compounds with Oxygen or Sulfur1h 6m
15. Aldehydes and Ketones1h 1m
16. Carboxylic Acids and Their Derivatives1h 11m
17. Amines39m
18. Amino Acids and Proteins1h 51m
19. Enzymes1h 37m
20. Carbohydrates1h 41m
21. The Generation of Biochemical Energy2h 8m
22. Carbohydrate Metabolism2h 22m
23. Lipids2h 26m
24. Lipid Metabolism1h 45m
25. Protein and Amino Acid Metabolism1h 37m
26. Nucleic Acids and Protein Synthesis2h 54m

26. Nucleic Acids and Protein Synthesis

Primary Structure of Nucleic Acids

GOB Chemistry

26. Nucleic Acids and Protein Synthesis

Primary Structure of Nucleic Acids

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1:46 minutes

Problem 39

Textbook Question

Are polynucleotides synthesized 3′ to 5′ or 5′ to 3′?

Verified step by step guidance

Polynucleotides, such as DNA and RNA, are synthesized in the 5′ to 3′ direction. This refers to the orientation of the sugar-phosphate backbone in the nucleotide chain.

The 5′ end of a nucleotide contains a phosphate group attached to the 5′ carbon of the sugar, while the 3′ end contains a hydroxyl (-OH) group attached to the 3′ carbon of the sugar.

During synthesis, the enzyme (e.g., DNA polymerase or RNA polymerase) catalyzes the formation of a phosphodiester bond between the 3′ hydroxyl group of the growing chain and the 5′ phosphate group of the incoming nucleotide.

This process ensures that the chain elongates by adding nucleotides to the 3′ end, maintaining the 5′ to 3′ directionality.

Understanding this directionality is crucial for interpreting processes like DNA replication, transcription, and the synthesis of complementary strands.

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Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Directionality of Polynucleotide Synthesis

Polynucleotides, such as DNA and RNA, are synthesized in a specific direction, which is 5′ to 3′. This means that nucleotides are added to the 3′ end of the growing chain, allowing the 5′ phosphate group of the incoming nucleotide to bond with the 3′ hydroxyl group of the last nucleotide in the chain.

Role of DNA and RNA Polymerases

DNA and RNA polymerases are enzymes responsible for synthesizing polynucleotides. They catalyze the formation of phosphodiester bonds between nucleotides, ensuring that the new strand is built in the 5′ to 3′ direction, which is crucial for accurate replication and transcription processes.

Implications of Synthesis Direction

The 5′ to 3′ synthesis direction has significant implications for biological processes, including DNA replication and RNA transcription. It affects how strands are paired and how enzymes function, leading to the necessity of mechanisms like Okazaki fragments during lagging strand synthesis in DNA replication.