Key Points : 1) Double Helix 2) Sugar-phosphate backbone 3) Nucleotide Rungs 4) Hydrogen bonds

Guanine Adenine Thymine Cytosine DNA Nucleotides:

Complementary Base Pairing: DNA GC AT

RNA: Ribonucleic Acid 1) Single stranded (usually) 2) Nucleotide Uracil replaces Thymine 3) Three species (for this course): 3.1) messenger RNA (mRNA) 3.2) ribosomal RNA (rRNA) 3.3) transfer RNA (tRNA)

Complementary Base Pairing: RNA GC AU

Histone protein complex DNA (a) the nucleosome: DNA wraps around histone proteins. (b) solenoids: loop of nucleosomes. (c): solenoids form a loop. (d): idealized cross section of a chromosome: several solenoid loops. (e): portion of a chromosome without the protein scaffold. DNA Packaging:

T G C A C G A T A T G T C G G A T C C T A A A T G C G C T A C A G C C T A G G A T T (a) DNA replication: strands separate T G C A C G A T A T G T C G G A T T A C G C G T A A T A T A T G C G C T A C A G C C A T T A C G C G T A A T A T (b) Synthesis of new, complementary strands.

Terms Amino acid = basic building block of polypeptide chains. Polypeptide chain = series of linked amino acids. AKA peptide chain. Protein = one or more polypeptide chains, folded and taking on a 3 dimensional configuration. Enzyme = a type of protein that speeds up chemical reactions. Try Tyr PheSerPheSerArgAlaPhe Tyr

Genetic Code (mRNA) 1) Triplet 2) Redundant 3) Universal

Five Steps in Protein Synthesis (PETAP): 1) Photocopying 2) Editing 3) Transportation 4) Assembly 5) Packaging

Five Steps in Protein Synthesis (PETAP): 1) Photocopying 2) Editing 3) Transportation 4) Assembly 5) Packaging = Transcription = Post-transcriptional modification = Transportation = Translation = Post-translational modification Common Sense TermsScientificese

I. Photocopying (Transcription) Definition: An RNA strand is synthesized from the DNA using complementary base pairing. Process: 1) “Transcription stuff” binds to a promoter region of the DNA. 2) An enzyme “slices” the DNA, making it single stranded. 3) Another enzyme (polymerase) synthesizes a strand of RNA using one of the DNA strands as a template.

DNA RNA transcript T G C A C G A U T T G G G A A C A C T A A A C U U G G U G A G A A C U U C

II. Editing (Post-transcriptional modification) Definition: Nonmessage segments in the newly synthesized RNA strand are edited out. Process: 1) Enzymes excise the introns (nonmessage segments) from the RNA strand. 2) Other enzymes splice together the exons (message segments) giving messenger RNA (mRNA).

exon 1intron 1exon 2intron 2exon 3 Punctuation marks Punctuation marks RNA transcript: exon 1intron 1exon 2intron 2exon 3 Editing: exon 1 Punctuation marks exon 2exon 3 Punctuation marks mRNA messemger RNA

III. Transportation (Transportation) Definition: mRNA is transported from the nucleus to the cytoplasm and attaches to a ribosome. Process: (same as the definition)

IV. Assembly (Translation) Definition: The mRNA codons are “read” and the corresponding amino acid is added to the polypeptide chain. Process: 1) A codon enters the “reading frame” of a ribosome. 3) The amino acid carried by the tRNA molecule is added to the polypeptide chain. 3) Steps 1 to 3 are repeated until all codons are “read.” 2) A transfer RNA (tRNA) molecule with the complementary anticodon binds to the codon of mRNA.

Trp CC A anticodon other RNA amino acid Transfer RNA (schematic) “bar code”

 2  1 GG AA    -like gene cluster on chromosome 11: length in kilobases (kb): Blow up of Exon 1 of the  hemoglobin gene: GTGCACCTGACTCCTGAGGAGAAGTTGGCC..AGG Nucleotides: Val His Leu Thr Pro Glu Glu Lys Ser Ala.. Arg Amino Acids: ACATTG: Start trans- scription here Exon 1Exon 2Exon 3Intron 1Intron 2 Promoters: TATA CAAT ATG: Start Translation Here TAA: Stop Translation Here CATTGC: Stop trans- scription here Attach a tail of multiple adenines here Blow up of the  hemoglobin gene: CodonNumber:

length in kilobases (kb):  -like gene cluster on chromosome 16:  1  2  1  2  1

Open window (A) and fly kite (B). String (C) lifts small door (D) allowing moths (E) to escape and eat red flannel shirt (F). As weight of shirt becomes less, shoe (G) steps on switch (H) which heats electric iron (I) and burns hole in pants (J). Smoke (K) enters hole in tree (L), smoking out opossum (M) which jumps into basket (N), pulling rope (O) and lifting cage (P), allowing woodpecker (Q) to chew wood from pencil (R), exposing lead. Emergency knife (S) is always handy in case opossum or the woodpecker gets sick and can't work.

The Self-Operating Napkin: As you raise spoon of soup (A) to your mouth it pulls string (B), thereby jerking ladle (C) which throws cracker (D) past parrot (E). Parrot jumps after cracker and perch (F) tilts, upsetting seeds (G) into pail (H). Extra weight in pail pulls cord (I), which opens and lights automatic cigar lighter (J), setting off sky-rocket (K) which causes sickle (L) to cut string (M) and allow pendulum with attached napkin to swing back and forth thereby wiping off your chin.