Do you know what this is? DNA Stands for Deoxyribose Nucleic Acid It is a long molecule called a polymer Shape: double helix DNA Located: nucleus of eukaryote cell Made up of repeating units of nucleotides DNA has 3 Basic Parts 5-Carbon Sugar called Deoxyribose Phosphorous group Nitrogenous Base A 5-carbon sugar, phosphate, and nitrogenous base is called a nucleotide A Nucleotide Nitrogenous Bases 4 Types of Nitrogenous Bases They are: Adenine, Thymine, Guanine, and Cytosine Nitrogenous bases are complimentarily paired Complementary Bases Adenine (A) always pairs with Thymine (T) Guanine (G) always pairs with Cytosine (C) What is the complimentary strand of this sequence? A-T-G-C-A-T-A-C-G-A-T-T-A-G-C T-A-C-G-T-A-T-G-C-T-A-A-T-C-G Double Helix 2 strands twisted around each other Each strand is made up a chain of nucleotides Strands are held together by Hydrogen Bonds between nitrogenous bases Chromosomes: DNA is on Chromosomes in the form of Genes GENES: 1) Small portions of DNA 2) Found on Chromosomes *add* Gene-chromosome theory is that genes are on chromosomes STOP STEP 1: DNA UNZIPS into 2 strands This structure is a Replication Fork DNA Replication Replication Fork- when it opens up Template (STEP 2) An enzyme takes free nucleotides and attaches them to the exposed strands of DNA The Original strand of DNA acts as a template for the new strand of DNA New Strand DNA Unzips Use Old Strands as a template How does DNA Replicate DNA uses enzymes to replicate DNA enzymes unzip the two strands The principal enzyme used is DNA Polymerase DNA Polymerase Polymerizes individual nucleotides to produce DNA Also Proofreads Its an enzyme STEP 3 You end up with 2 strands of DNA STOP DNA codes for Proteins Proteins become enzymes, and are what genes express Protein Synthesis Building blocks: amino acids Their shape determines their function Proteins are polymers of amino acids *Polymers are long chains Proteins Refresher It is a nucleic acid just like DNA It is single stranded, its sugar is Ribose, and has 4 Nitrogenous bases. RNA: Ribonucleic Acid 4 Nitrogenous Bases Adenine Uracil (NOT THYMINE) Guanine Cytosine DNA: A-T-G-T-T-A-A-A-A-G-C RNA: U-A-C-A-A-U-U-U-U-C-G RNA still follows the complementary base pairing, BUT SUBSTITUTES U FOR T Practice Converting DNA to RNA mRNA (Messenger RNA) rRNA (Ribosomal RNA) tRNA (Transfer RNA) 3 Types of RNA 1. mRNA: Messenger RNA JOB: Carries a copy of DNA from the nucleus to the ribosome JOB: Clamps onto mRNA and uses its information to make amino acids 2. rRNA: Ribosomal RNA Job: transfers amino acids to ribosome 3. tRNA: TRANSFER RNA m in mRNA is for Messenger t in tRNA is for Transfer Ribosome stop 2 stages 1) Transcription 2) Translation Protein Synthesis WAIT, WHAT DOES SYNTHESIS MEAN? 1. WHERE: NUCLEUS 2. WHAT: DNA double helix unzips 3. WHO: mRNA TRANSCRIPTION Transcription 1. mRNA copies the DNA code 2. mRNA leaves the nucleus and brings the code to a ribosome 3. Similar to DNA Replication, but RNA is single stranded and uses U instead of T Ribosome On its way to ribosome mRNA leaves EX: mRNA DNA: A-T-G T-C-A mRNA: U-A-C A-G-U RNA-NO THYMINE! Genetic Code EVERY 3 Nucleotides code for 1 Amino Acid EX: U-U-U codes for Phenylalanine Each set of 3 nucleotides in mRNA is called a CODON There are Codons that STOP and START the production of Proteins 1. WHERE: Cytoplasm and ribosomes 2. mRNA molecule attaches to a ribosome 3. As each codon of the mRNA moves through the ribosome,the proper amino acid is brought in by tRNA an attached to the mRNA. 2. Translation Translation 1. The anticodon on tRNA matches the codon of mRNA. 2. mRNA continues to move through the ribosome and tRNA continues to add amino acids. Whats an Anticodon? It is the complement of the Codon Remember the codon is 3 nucleotides from mRNA mRNA Codon: U-U-U tRNA ANTI-CODON A-A-A Carries the Anticodon on one end An Amino acid is located on the other end of tRNA tRNA