How Does a Cell Copy Its DNA? | DNA Replication Explained

Every time a cell divides, it has to make an incredibly accurate copy of its DNA. But how can a cell copy a molecule containing billions of pieces of information? There is no photocopier inside the cell. Instead, an extraordinary collection of molecular machines works together to replicate DNA. In this video, we go inside the DNA replication process and discover how it works. We'll explore: 🧬 What DNA is and why its two strands are complementary 🔓 How helicase separates the DNA strands 🧩 How each original strand becomes a template ⚙️ How DNA polymerase builds a new DNA strand ➡️ Why DNA synthesis happens in the 5′ → 3′ direction 🧪 Why the two DNA strands cannot be copied in exactly the same way 🧵 What the leading and lagging strands are 🔹 What Okazaki fragments are 🧬 Why DNA needs an RNA primer 🔗 How DNA ligase joins DNA fragments 🔍 How DNA polymerase helps detect and correct mistakes ♻️ Why DNA replication is called semiconservative replication But more importantly, we'll ask a bigger question: How can a molecule carry information—and then use that information to make an accurate copy of itself? Rather than memorising a list of enzymes, we'll follow the problem the cell has to solve and see why each molecular machine is needed. This is molecular biology beyond the textbook. Because biology becomes much more fascinating when we stop asking only: “What happens?” and start asking: “How does it happen?” 🔬 Next: How does a cell read the information stored in DNA and use it to make a protein? #DNAReplication #DNA #MolecularBiology #CellBiology #Genetics #BiologyForKids #ScienceForKids #BiologyBeyondTheTextbook #ScienceEducation #STEM