Lesson 4 of 8
Lesson 4: DNA, RNA, and Protein Synthesis
DNA is the instruction manual for building and running an organism. It is passed from parents to offspring.
Structure of DNA
- ●DNA is shaped like a twisted ladder called a double helix
- ●The rungs are made of paired bases: A, T, C, and G
- ●Base pairing rule: A pairs with T, and C pairs with G
- ●A gene is a section of DNA that codes for one protein
KEY TERM
RNA is a single-strand helper molecule that carries DNA instructions out of the nucleus to the ribosome. In RNA, the base uracil (U) takes the place of thymine (T).
Making a Protein (Two Steps)
- 1Transcription: DNA is copied into messenger RNA inside the nucleus
- 2Translation: the ribosome reads the RNA in three-letter codons and links amino acids into a protein
ON THE TEST
Remember the flow of information: DNA to RNA to protein. Proteins do most of the work in your body, from building muscle to speeding up reactions.