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

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

mRNA Function: Reads the DNA (ATCG) and carries its message to a ribosome Location: Starts in nucleus… moves to ribosome

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

rRNA Function: Used to build ribosomes Location: Cytoplasm Ribosome: Makes proteins

Transcription Defined: Process of making mRNA from DNA – Copying of a gene to eventually make a protein. Step 1: RNA Polymerase separates the DNA nucleotides Step 2: Free floating RNA nucleotides match with the DNA Reminder: U replaces T Step 3: mRNA breaks free in separate pieces 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

Transcription Animation

RNA polymerase

DNA vs. RNA Double Stranded Sugar: Deoxyribose Bases: A T C G Location: Nucleus Single strand Sugar: Ribose Bases: A U C G Location: Nucleus & Cytoplasm Replication vs. Transcription Complex enzymes are used Base pairing rules guide replication A=T, G=C Copies DNA Only one copy of DNA is made Location: Nucleus Complex enzymes are used Base pairing rules guide replication 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