Protein Synthesis: An Overview 2009-2010

Bodies  Cells  DNA Bodies are made up of cells All cells run on a set of instructions spelled out in DNA

DNA  Proteins  Cells  Bodies DNA has the information to build proteins genes proteins cells DNA gets all the glory, Proteins do all the work bodies

How do proteins do all the work proteins run living organisms enzymes control all chemical reactions in living organisms structure all living organisms are built out of proteins

Cell organization DNA DNA is in the nucleus genes = instructions for making proteins want to keep it there = protected “locked in the vault” cytoplasm nucleus

Cell organization Proteins chains of amino acids made by a “protein factory” in cytoplasm protein factory = ribosome cytoplasm nucleus build proteins ribosome

Passing on DNA information Need to get DNA gene information from nucleus to cytoplasm need a copy of DNA messenger RNA cytoplasm nucleus build proteins mRNA ribosome

Central Dogma DNA carries codes for protein synthesis Since DNA must remain in the nucleus, mRNA is needed to “transcribe” the DNA code, and to carry the code to the ribosomes in the cytoplasm Once attached to a ribosome, the mRNA message is then “translated” into polypeptide chains

DNA mRNA protein trait Central Dogma transcription translation nucleus cytoplasm

DNA vs. RNA DNA RNA deoxyribose sugar nitrogen bases double stranded G, C, A, T T : A C : G double stranded RNA ribose sugar nitrogen bases G, C, A, U U : A C : G single stranded

RNA 3 kinds of RNA (in protein synthesis) mRNA Messenger RNA Long single strand of RNA Made in the nucleus Moves out to ribosomes in cytoplasm Carries genetic information from DNA onto ribosome for translation into a protein

RNA 3 kinds of RNA mRNA tRNA Transfer RNA 60 kinds Each attached to a particular amino acid Transfers them to the mRNA at the ribosome

RNA 3 kinds of RNA mRNA tRNA rRNA Ribosomal RNA Associated with proteins contained in ribosomes Site of protein synthesis