8.5 Translation LEQ: How is RNA translated? Activator: Collins I 4 facts about the processes of transcription and editing: Key terms – translation, codon

8.5 Translation Translation Overview: All cells require three types of RNA in order to make a protein based on the information in a gene:

8.5 Translation Amino acids are coded by mRNA base sequences. Codons are made of 3 mRNA bases that encode: –amino acid (and/or) –stop/start signal codon for methionine (Met) codon for leucine (Leu)

8.5 Translation The genetic code matches each RNA codon with its amino acid or function. Review the table; create 3 “I noticed…” statements

8.5 Translation Transcribe & Translate 1) Transcribe the following DNA: –TAC 2) Translate using your codon table 3) Transcribe & translate the following DNA: –TAC CTT CTG CGG Problem set

8.5 Translation

Ribosomes (rRNA) synthesize proteins. tRNA use anticodons translate codons. Bring amino acids

8.5 Translation Initiation - tRNA binds to a start codon, ribosome assembles. –advances mRNA to next codon –aa-tRNA enters first site (A site) –ribosome forms bond between the amino acids.

8.5 Translation Elongation - empty tRNA molecule exits at third site (E site). –repeat. Termination – at stop codon, translation stops –Protein “folds” as it is produced

8.5 Translation Summary: Answer translation questions Finish translation practice problems

8.5 Translation Post-translation occurs in the endo membrane system The Golgi, ER, and vesicles change (and ship) proteins.

8.5 Translation –modifications: sugars, lipids, metals, etc –Folded, cut to function

8.5 Translation A small genome can give rise to a complex proteome.

8.5 Translation

Summary Questions: Why are proteins chemically modified after they are assembled by a ribosome? Why do cells have nearly limitless variety of protein chemistry?

8.5 Translation

The process of translation involves establishing a reference for interpreting information.