Part 1: Introduction to Molecular Biology
What is Molecular Biology?
Molecular biology is the study of biology at the molecular level, focusing on the structure and function of the macromolecules essential to life. It examines how biological information is stored, transmitted, and expressed through DNA, RNA, and proteins.
This field bridges biochemistry and genetics, providing the foundation for understanding how living organisms function at their most fundamental level.
Course Overview
1.1 Overview and History
- • What is Molecular Biology?
- • Historical Development
- • Key Discoveries Timeline
- • The Central Dogma
- • Model Organisms
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1.2 Chemical Foundations
- • Chemical Bonds in Biomolecules
- • Water and pH in Biology
- • Thermodynamics of Biomolecules
- • Macromolecule Overview
- • Cellular Organization
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The Central Dogma of Molecular Biology
The central dogma, proposed by Francis Crick in 1958, describes the flow of genetic information:
🧬
DNA
→
Transcription
→
📜
RNA
→
Translation
→
🔶
Protein
This unidirectional flow explains how genetic information is expressed: DNA is transcribed into RNA, which is then translated into proteins that carry out cellular functions.
Key Milestones in Molecular Biology
1869
Friedrich Miescher discovers "nuclein" (DNA)
1944
Avery-MacLeod-McCarty experiment proves DNA is genetic material
1953
Watson & Crick describe DNA double helix structure
1958
Meselson-Stahl confirm semi-conservative DNA replication
1961
Nirenberg & Matthaei crack the genetic code
1977
Sanger develops DNA sequencing method
2003
Human Genome Project completed
Learning Objectives
- ✓Understand the scope and importance of molecular biology
- ✓Describe the central dogma and information flow in cells
- ✓Explain the chemical basis of biological molecules
- ✓Recognize key historical experiments and discoveries
- ✓Identify model organisms used in molecular biology research