Learn: DNA Replication, Mutations and Cystic Fibrosis

Welcome!You've already studied DNA structure and function, and how enzymes work in living systems. Now, let's build on that to understand DNA replication, how mutations occur, and how they can lead to conditions like Cystic Fibrosis.

What is DNA Replication?DNA replication is the process by which cells make an exact copy of their DNA before dividing. It ensures that each new cell has the same genetic information. This is essential for growth, repair, and reproduction.

How does DNA Replication work?DNA replication begins when the enzyme helicase unwinds the double helix, breaking hydrogen bonds between bases. Another enzyme, DNA polymerase, adds complementary nucleotides to each strand based on the base-pairing rules (A pairs with T, and C pairs with G).

What are Mutations?A mutation is a change in the DNA sequence. Mutations can occur naturally during replication or be caused by external factors like radiation or chemicals. Some mutations have no effect, while others can disrupt normal protein function.

What is Cystic Fibrosis?Cystic Fibrosis is a genetic disorder caused by a mutation in the CFTR gene. The CFTR protein regulates the movement of chloride ions in cells. A faulty version leads to thick mucus build-up in the lungs and digestive system, causing breathing difficulties and digestive issues.

How do mutations cause Cystic Fibrosis?A mutation in the CFTR gene changes the protein's structure, preventing it from working properly. This disrupts ion transport, leading to a build-up of thick mucus in the lungs and other organs.

Review Time!Great work! You've learned about DNA replication, mutations, and Cystic Fibrosis. Let's review your understanding with a few questions.