Transcription and Translation Structure of RNA • Similar to DNA • 5 carbon sugar • Phosphate group • Nitrogenous base • 3 main differences • Ribose sugar rather than deoxyribose • Single stranded rather than double stranded • Bases are Adenine, Uracil, Guanine, Cytosine • Disposable copy of DNA Types of RNA • mRNA • The message of DNA to code for a gene • tRNA • Used to bring amino acids together when creating proteins • rRNA • Forms ribosomes, along with proteins Transcription • Production of RNA from DNA • Requires RNA polymerase • Function? • Started by helicase proteins • Promoters • Regions of DNA that allows RNA polymerase to bind to it • Signal points for the beginning of a gene After Transcription • RNA produced requires editing before it is an active form • Introns: sequences of DNA found in eukaryotic genes • Must be removed from RNA before it can be used to produce proteins • Exons: segments of DNA that code for proteins • Stay in DNA • Both introns and exons are formed from DNA Genetic Code • Amino acids are joined together in long chains to form proteins (polypeptides) • Each combination of amino acids means the proteins have different properties • Codon • Three nucleotides that code for a specific amino acid • mRNA is read 3 bases at a time, each 3 bases is one codon • UCGCACGGU UCG-CAC-GGU Serine – Histidine – Glycine Translation • Turning mRNA into a protein • Requires ribosomes • Occurs in 3 steps • mRNA in cytoplasm attaches to a ribosome. mRNA moves through the ribosome, each codon is read and a tRNA brings the matching amino acid and attaches them together. • Peptide bond is formed between amino acids to hold protein together. At the same time, ribosome breaks the bond holding the amino acid to the tRNA then releases the tRNA. • Continues to grow until the ribosome reads a stop codon Genes and Proteins • Proteins control every physical characteristic • Genes control production of enzymes to produce skin pigment • Genes also control enzyme production that determines blood type Activity • Make a drawing showing the process of transcription and translation • Underneath the picture, write a one paragraph summary of the lecture notes.