Overview
This lecture explains how DNA instructions are converted into proteins through the process of transcription, highlighting the role of various molecules and the creation of RNA.
DNA and Genes
- DNA contains genetic instructions organized into segments called genes.
- A gene is a specific length of DNA that contains instructions for making a protein.
Initiation of Transcription
- Specialized factors assemble at the start of a gene to begin the process.
- These factors trigger the transcription phase, where genetic information is read.
The Transcription Process
- An enzyme moves along the DNA, unzipping the double helix and copying one strand.
- This enzyme builds a complementary RNA molecule based on the DNA sequence.
- RNA is a chemical cousin of DNA, used as a messenger in this process.
- RNA is synthesized by matching DNA bases (A, C, G, T) to RNA bases, with "T" replaced by "U" (uracil) in RNA.
Real-Time Activity
- Transcription occurs continuously in nearly every cell of the body.
Key Terms & Definitions
- Gene — a segment of DNA with instructions to make a protein.
- Transcription — the process of copying DNA into RNA.
- RNA — ribonucleic acid, a molecule similar to DNA but with uracil (U) instead of thymine (T).
- Enzyme — a protein that speeds up chemical processes, here used to copy DNA into RNA.
- Uracil (U) — an RNA base that replaces thymine (T) found in DNA.
Action Items / Next Steps
- Review the steps and molecules involved in transcription.
- Learn the differences between DNA and RNA bases.