Structure and Function of DNA DNA Replication and Protein Synthesis

 Double Helix in Shape- two stands wound around one another.  Composed of subunits called nucleotides  Parts of a Nucleotide  5 Carbon Sugar- Deoxyribose  Phosphate Group  Nitrogen Base (4 Flavors)  Adenine, guanine, cytosine, and thymine (A,T,C,G) DNA Structure

Nucleotides of a DNA Molecule

 Credited with Double Helix Model  Spiral staircase or twisted ladder  Maurice Williams and Rosalind Franklin worked with them also. Watson and Crick

 Chargoff’s Rule  A,C,T, G always bind in a certain way  Adenine- Thymine  Cytosine- Guanine  Hydrogen Bonds Hold Them Together Base Paring

 DNA stores all of the genetic information for the cell.  If it located in the nucleus but can also be found in the mitochondria and the chloroplast.  Serves as the blueprint for making proteins. Function of DNA

 Copying DNA to make an exact copy (in nucleus)  DNA strand unwinds and separates  Enzymes help new DNA chains form by using nucleotides floating around the nucleus.  Produces two new exact copies of the original DNA strand.  Occurs during S phase if interphase  Remember A-T and C-G !!! DNA Replication

 1. CTC GGG ATA CTG GGG CGT  2. ATG GCG CGT CGT CAT TAC  3. GTG CGT CAT CCC AAA TTT  4. TAC CAT ATC GTA CGT GTA  5. AAT TTA TAT CTC GTG CCC Replication Practice

 Ribonucleic Acid  Structure of RNA  Made of nucleotides  Sugar-Ribose  Uracil Replaces Thymine and Pairs with Adenine  Single Strand not double  Smaller than DNA Part II: RNA

 mRNA- messenger RNA  Carries RNA info from nucleus to cytoplasm  tRNA- transfer RNA  Picks up amino acids  rRNA- ribosomal RNA  Makes up the ribosomes where proteins are made. Types of RNA

DNA VS. RNA

 DNA  RNA  Occurs in the nucleus  When the cell needs a protein is transcribes a certain part of DNA into RNA.  RNA is then the directions to make the proteins. Transcription

 1. TAC GGC TAT ATC CTG CGC TAT ACG ATT  2. TAC CCG GAT CCG TTC ATA CGT ACT ATC  3. TAC GTA AAA AGT GGG CCC TAT GAT ATT  4. TAC GTA CGT CAT GAT TAG AGT TCT ATC  5. TAC GTA CTA GTA CCC GTA ATA AGA ATC Transcription Practice

 RNA is read in sets of 3 bases called codons.  Each codon CODES for a specific amino acid.  Start Codon –AUG  Stop Codons- UAA, UAG, UGA The Genetic Code

 Making proteins from the mRNA code.  mRNA leaves the nucleus and moves to the cytoplasm.  Goes to the ribosome where it is read is sets of 3 bases called a CODON.  tRNA picks up amino acids needed to make specific proteins Translation

 Structure of Proteins  Polymers made of amino acids bonded by peptide bonds.  Specific sequence of amino acids makes each protein.  There are 20 different amino acids used to make proteins.  Protein Synthesis

 Once at the ribosome, the amino acids brought by the tRNA are bonded together by peptide bonds.  Bonded by peptide bonds.  MAKES A PROTEIN. Protein Assembly

SUMMARY PROCESSMOLECULESLOCATION REPLICATION TRANSCRIPTION TRANSLATION

 Transcribe and Translate the following sequences. 1.DNA- TAC GGT ACT TAG AGA TTT AAA ATT RNA AA 2. DNA- TAC GTG GGG TTT ACT TCA CAT TTC GAG RNA AA Translation Practice