RNA and Transcription

The Central Dogma States: Genetic information flows in one direction from DNA to RNA to proteins. replication transcription Includes 3 processes: Replication Transcription Translation translation RNA is the link between DNA and proteins.

Ribonucleic Acid Single nucleotide strand Sugar: Ribose 4 Bases: A: Adenine G: Guanine C: Cytosine U: Uracil U replaces T Three Types of RNA

Messenger RNA AKA: mRNA Function: Copies a section of DNA (gene) and travels to a ribosome Link between DNA and proteins Allows ribosome to create a protein Location: Starts in nucleus… moves to ribosome

Transfer RNA Amino acid Proline Amino acid Serine AKA: tRNA Function: Transfers amino acids from the cytoplasm to the ribosome Ribosome will link amino acids together to form a protein Location: Cytoplasm

Ribosomal RNA Location: Cytoplasm AKA: rRNA Function: components of ribosomes Location: Cytoplasm

Transcription U| C| A| A| U| C| A| U| U| C| G| G| G| Defined: Process of making mRNA from a sequence of DNA Step 1: RNA Polymerase separates the DNA nucelotides Step 2: Free floating RNA nucleotides match with the DNA Reminder: U replaces T Step 3: mRNA breaks free Step 4: mRNA processing takes place Unused portions (introns) are removed and the used portions (exons) bond together Step 5: Final mRNA strand travels to ribosome Step 6: DNA recombines to be used again G| C| A| A| G| U| C| A| U| U| C|

Transcription Animation flash animation

Step 5 & 6: mRNA travels to ribosome and DNA reconnects Step 2: Free floating mRNA nucleotides match up Step 1: RNA polymerase splits the DNA Step 4: mRNA Processing (exons bond together) Step 3: mRNA breaks free RNA polymerase

Transcription Video

DNA & RNA Comparison DNA vs. RNA Replication vs. Transcription # of strands: Two (Double) Sugar: Deoxyribose Bases: A T C G Location: Nucleus # of strands: One (Single) Sugar: Ribose Bases: A U C G Location: Nucleus & Cytoplasm Replication vs. Transcription Enzymes: DNA Helicase and DNA Polymerase Base pairing rules: A=T, G=C Copies: DNA Only one copy of DNA is made Location: Nucleus Enzymes: RNA Polymerase Base pairing rules: A=U, G=C Copies: a gene Many copies and types of RNA are made Location: Nucleus

Review Name three different ways that DNA and RNA differ. Which RNA: is found inside the nucleus? transports amino acids to the ribosome? exits the nucleus to the ribosome? copies the DNA code? makes up the structure of ribosomes? Perform transcription by using the following piece of DNA. Introns are underlined. Write the final strand of mRNA created. T A C C G T A C A A T G G G A T C