About This Chapter
DNA Structure & Replication - Chapter Summary
The structure and replication of DNA is clearly laid out in the video lessons that make up this chapter. Our engaging videos cover subjects such as the structure of the nucleosome and the process of DNA replication, amongst others. You can watch these videos as many times as needed, using the video tabs feature to go back and review any of the sections again. If at any time you need help, our experts are available to answer your questions in the Dashboard. After finishing this chapter, you should be ready to:
- Explain how DNA is organized into chromosomes
- Define the nucleosome and its structure
- Outline the chemical structure of nucleic acids and phosphodiester bonds in DNA
- Discuss adenine, guanine, cytosine, thymine and complementary base pairing
- Differentiate between the models of DNA replication
- Identify how helicase unwinds the DNA double helix in preparation for replication
- Explain how DNA polymerase and RNA primase initiate DNA replication
- Detail the leading strand and DNA polymerase activities in DNA replication
- Provide a review of replication bubbles, enzymes and leading and lagging strands
1. How is DNA Organized into Chromosomes? - Structure & Function
Explore the structure of chromosomes and see how DNA fits inside the nucleus of the cell. In this lesson, you'll learn about histones, chromatin and nucleosomes.
2. Nucleosome: Definition & Structure
Each of your cells has about 2 meters of linear DNA. This has to be packed into a nucleus roughly 10 micrometers in diameter. This means your nucleus must be excellent at packaging your genetic material! This lesson tells you how your DNA is packaged.
3. Spindle Fibers: Definition, Location & Purpose
During mitotic and meiotic cell division many structures form and disappear as part of the way to organize the cell. One such consideration is the spindle fiber. How do we end up with two unique cells? We find out here.
4. DNA: Chemical Structure of Nucleic Acids & Phosphodiester Bonds
In this lesson, you'll discover what nucleotides look like and how they come together to form polynucleotides. We'll also explore nucleic acids and focus on DNA in particular.
5. DNA: Adenine, Guanine, Cytosine, Thymine & Complementary Base Pairing
Learn the language of nucleotides as we look at the nitrogenous bases adenine, guanine, cytosine and thymine. Armed with this knowledge, you'll also see why DNA strands must run in opposite directions.
6. What Is DNA Replication? - Conservative, Semi-Conservative & Dispersive Models
How do we know that DNA replication is semi-conservative? How do we know it's not conservative or dispersive? Let's follow the famous experiment by Meselson and Stahl to find out!
7. How Helicase Unwinds the DNA Double Helix in Preparation for Replication
How does semi-conservative replication begin? Discover how DNA helicase creates a replication fork to unwind the complicated DNA molecule and allow daughter strands to form on the parental template.
8. How DNA Polymerase and RNA Primase Initiate DNA Replication
How do enzymes assist in starting DNA replication? In this lesson, we explore the work of a contributing enzyme, DNA polymerase, and learn how the RNA primer is made by the action of RNA primase.
9. DNA Replication: The Leading Strand and DNA Polymerase Activities
How does replication occur in the antiparallel DNA molecule? In this lesson, explore the significance of the leading and lagging strands, and learn how Okazaki fragments and RNA ligase make DNA replication possible.
10. DNA Replication: Review of Enzymes, Replication Bubbles & Leading and Lagging Strands
Feeling lost in the thorny details of DNA replication? This lesson provides an overview of semi-conservative replication, with a focus on putting together all of the concepts involved. We'll review the work of each enzyme on our way to completing the big picture of DNA replication.
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Other chapters within the Biology 203: Cell & Molecular Biology course
- Biological Molecules
- Cell Structure & Function Overview
- Cell Membrane & Transport Overview
- Principles of Cell Metabolism
- Photosynthesis Fundamentals
- Cellular Respiration & Fermentation
- Cell Cycles
- Patterns of Genetic Inheritance
- Mutation & DNA Damage
- The Central Dogma of Biology & Protein Synthesis
- Structure & Function of Viruses
- Control of Gene Expression
- Genetic Manipulation Overview