Protein Synthesis

Remember: DNA Replication

How does DNA make all of our characteristics? Genes make proteins…

Nucleic Acids To make proteins, we need both types of nucleic acids: DNA and RNA Deoxyribonucleic Acid Ribonucleic Acid

Nucleic Acids DNARNA SugarDeoxyriboseRibose BasesA C G TA C G U StrandDoubleSingle Wherever DNA has the base thymine, RNA has the base uracil.

3 Types of RNA Messenger – mRNA Transfer – tRNA Ribosomal – rRNA

Protein Synthesis The process of reading DNA to make proteins is called protein synthesis.

The Central Dogma of Genetics says that genetic information goes from DNA  RNA  Protein. The steps of the Central Dogma are: 1. DNA Transcription 2. RNA Translation 3. Protein Folding.

Step 1: Transcription An mRNA strand is formed from the DNA. Just like in DNA Replication, helicase unzips the DNA and RNA Polymerase builds the new mRNA strand.

Three letters in a row on the mRNA is called a codon. The matching three letters on tRNA is called an anticodon.

Step 2: Translation Ribosomes read the mRNA. A tRNA molecule with the right anticodon matches up to the mRNA codon and attaches the correct amino acids to the chain.

Protein Folding Once the amino acid chain is complete, it leaves the ribosome and goes through the Rough ER and the Golgi Apparatus to be folded in to its protein shape.

Check Your Understanding 1.How is RNA different from DNA? 2.What does the Central Dogma of Genetics say? 3.What are the two steps of Protein Synthesis and what happens in each step? RNA is a single strand, has ribose sugar instead of deoxyribose, and uses the base uracil instead of thymine. DNA  RNA  Protein 1.Transcription – DNA is transcribed (copied) into mRNA 2.Translation – mRNA is translated into an amino acid chain