Transcription Translation Do Now 1 Get out yesterdays

Transcription & Translation Do Now: 1. Get out yesterday’s homework (10 -1 review) 2. If a DNA strand has the nucleotide sequence TCC-GAT-AAT, what will the sequence of an RNA copy be?

Transcription • Transcription makes an RNA copy of a DNA sequence. • All of a cell’s RNA is made by transcription. (m. RNA, t. RNA, r. RNA, etc. )

The Big Idea (aka “central dogma”) n o i pt ri c ns Replication an r T a r T DNA n io t a sl m. RNA Protein

The strands of DNA are Antiparallel • Antiparallel means the two strands are parallel, but have opposite orientations.

5’ & 3’: The two different ends of a nucleotide strand • The numbers 5’ and 3’ refer to different carbon atoms in the sugar of a nucleotide. • The 5’ end of a strand has a phosphate attached to it. The 3’ end does not

DNA & RNA Polymerase • Polymerases are enzymes that make nucleotide polymers. In other words, they make new strands of DNA or RNA. • DNA polymerase makes new DNA strands. • RNA polymerase makes new RNA strands.

Polymerases Follow a Template Strand • Notice that RNA polymerase is copying the “template strand” of DNA. The “coding strand” has the same sequence as the new RNA molecule. • Only correctly base-paired matches are added • Polymerases add nucleotides to the 3’ end of a molecule

RNA Polymerase at Work

Recap of Key Ideas • The two strands of a DNA molecule are antiparallel, meaning one is upside down compared to the other. • Transcription is the process that makes all of a cell’s RNA. • DNA polymerase and RNA polymerase are enzymes that copy a template strand of nucleotides. (DNAP makes DNA, RNAP makes RNA).