DNA for Dummies and the intellectually astute A

DNA for Dummies (and the intellectually astute) A Dr. Parrott Production

• Secret of Photo 51: • Ribosome orchestrates this event

DNA Wrap Basic DNA Wrap Advanced Chromosome Packing DNA Coiling

Replication: DNA • Occurs during S phase of interphase in reproducing cells only • DNA template is copied complimentarily and semi conservatively • Occurs only in the nucleus

Meselson-Stahl Experiment DNA Replication Complete How DNA Replicates Bidirectional Replication

Make a DNA strand complimentary to the following: DNA: ATG GTG CAC CTG ACT CCT GTG GAG AAG TCT DNA: TAC m. RNA: Amino Acids: t. RNA:

DNA Replication Basic DNA Replication Fork DNA Replication DNA Polymerase Rep Fork 2

Tran scription: DNA m. RNA • Occurs continually throughout the cell cycle with the exception of mitosis • Occurs in the nucleus as messenger RNA copies DNA

Transcription Basic RNA Splicing Transcription Complete Protein Synthesis

Make a DNA strand complimentary to the following: DNA: ATG GTG CAC CTG ACT CCT GTG GAG AAG TCT DNA: TAC Transcribe the above DNA template into an m. RNA: UAC Amino Acids: t. RNA:

Translation: m. RNA protein • Occurs continually throughout the cell cycle • Occurs at the ribosome as it – – reads the m. RNA codons Matches codons to amino acids Prompts t. RNA to bring a. a. Attaches a. a. with peptide bonds DNA to Protein

Translation • t. RNA anticodon is complimentary to m. RNA codon • t. RNA is specific to the amino acid it brings • Peptide bonds connect amino acids to form polypeptide (protein) Translation Basic Protein Synthesis 2 Translation Advanced Protein Synthesis

Protein Synthesis

Make a DNA strand complimentary to the following: DNA: ATG GTG CAC CTG ACT CCT GTG GAG AAG TCT DNA: TAC m. RNA (codons): UAC Translate the above m. RNA strand into an amino acid sequence (protein) Amino Acids: Tyrosine t. RNA (anticodons):

• Watch RNAi Online: http: //www. pbs. org/wgbh/nova/sciencenow/321 0/02. html

Make a DNA strand complimentary to the following: DNA: ATG GTG CAC CTG ACT CCT GTG GAG AAG TCT DNA: TAC m. RNA (codons): UAC Amino Acids: Tyrosine What are the anticodons on the t. RNA for the above strands? t. RNA (anticodons): AUG

To summarize…

Mistakes/Mutations • Mutation any permanent alteration in the sequence of DNA bases • Point mutations can result in frameshifts in the reading frame • Chromosomal mutations can result in translocations

Mistakes/Mutations • Silent mutation change in n. t. sequence, but no change in product • Missense mutation swapping of a. a. (sickle cell anemia, PKU) • Nonsense mutation insertion of stop codon into sequence Silent Mutation G

Resources • • • Genetics Movies: http: //www. dpo. uab. edu/~landrews/genetics. htm DNA Tutorial: http: //www. ncc. gmu. edu/dna/index. htm Bacterial Replication Animations: http: //www. wwnorton. com/college/biology/mbio/animations/dna_replication. asp Telomere Synthesis (shortening of linear chromosomes): http: //spine. rutgers. edu/cellbio/assets/flash/tel. htm Gene Processing http: //highered. mcgrawhill. com/sites/0072437316/student_view 0/chapter 15/animations. html Replication Animations: http: //highered. mcgrawhill. com/sites/0072437316/student_view 0/chapter 14/animations. html Gene Expression Animations: http: //highered. mcgrawhill. com/sites/0072437316/student_view 0/chapter 18/animations. html# Gene Technology: http: //highered. mcgrawhill. com/sites/0072437316/student_view 0/chapter 16/animations. html