Central Dogma DNA is the genetic material within the nucleus. Replication The process of replication Gel electrophoresis creates new copies of DNA. DNA The process of transcription DNA sequencing creates an RNA using RNA DNA information. Nucleus The process of translation Translation

creates a protein using Protein RNA information. Cytoplasm

DNA Double Helix-Held Together with H-Bonds

1 Three Components of DNA Structure Base Pairs Double Helix

base: thymine monophosphate (pyrimidine)

α sugar: 2’-deoxyribose

5’

4’ 1’ (5’ to 3’) 3’ 2’ 3’ linkage

base:adenine (purine) 5’ linkage no 2’-hydroxyl

Pyrimidines used in Base Pairs, Purines used in Base Pairs, DNA DNA

Fused 5 and 6 member rings 6-membered rings only

2 DNA Base Pairing A-T and G-C Base Pairs Hold the DNA helices together A-T pairing 2 H-Bonds

G-C pairing 3 H-bonds

A-T and G-C Base Pairs Hold the A-T and G-C Base Pairs Hold the DNA helices together DNA helices together

3 A-T and G-C Base Pairs Hold the A-T and G-C Base Pairs Hold the DNA helices together DNA helices together

Hydrogen-Bonding’s Role in DNA Structure Transcription • The new RNA molecule is formed by incorporating • that are complementary to the template strand.

DNA coding strand DNA

5’ GTCA TTCGG

3’ 3’ G U C A U U C G G 3’

CAGTAAGCC 5’

DNA template strand 5’

RNA

4 RNA Polymerase is the Enzyme that Catalyzes Transcription of DNA Information to RNA # of strands DNA (Blue)

Newly Synthesized RNA (Red) kind of sugar Bridge Helix Moves DNA through Polymerase during RNA Synthesis (Green) bases used Active Site Metal (Pink)

Transcription Translation • The new RNA molecule is formed by incorporating • The process of reading the RNA sequence of an • nucleotides that are complementary to the mRNA and creating the amino acid sequence of a template strand. protein is called translation.

DNA coding strand DNA DNA DNA template TTCAGTCAG 5’ strand GTCA TTCGG Transcription AAGUCAGUC Messenger 3’ RNA 3’ mRNA G U C A U U C G G 3’ Codon Codon Codon

CAGTAAGCC 5’ Translation

DNA template strand 5’ Polypeptide Protein Lysine Serine Valine (amino acid sequence) RNA

5 Genetic information written in codons is translated into amino acid sequences

• The “words” of the DNA “language” are triplets of bases called codons – 3 bases or nucleotides make one codon – Each codon specifies an amino acid – The codons in a specify the amino acid sequence of a polypeptide

The is the Rosetta stone of life

• Tryptophan and • Virtually all Methionine have only 1 codon each organisms • All the rest have share the same more than one genetic code • AUG has a dual • All organisms function use the same • 3 stop codons that code for termination 20 aa of protein synthesis • Each codon • Redundancy in the specifies a code but no particular aa ambiguity

Figure 10.8A Figure 10.8A

6 http://www.dnalc.org/ddnalc/resources/sangerseq.html

http://www.shsu.edu/~chm_tgc/sounds/flashfiles/GE.swf

7 Shotgun sequencing: assembly of random sequence fragments

8