DNA,RNA, AND BACTERIAL MOLECULAR METABOLISM

Nucleic Acids (dna)

Role in heredity, structure(polymer and a building block), dna synthesis

Early experiments demonstrated that DNA is material of inheritance , findings are :

• smooth vs rough bacteria (Griffith Avery)

• Bacteriophage infection (Hershey chase)

• Cancer formation (bishop varmus)

• Animal cloning (more recent)

Rough and smooth bacteria is dependent on …

If the bacteria can produce a capsule

Hershey and Chase 1952 proof with radioactivity experiments

• used bacteriophage T2 infection model

• DNA P32

• Protein coat s35

• DNA only for transcript, protein coat will get lost

Transformation

DNA release → DNA uptake → new phenotype

Transduction

Virus → host → new phenotype

Nucleotide structure

The information part (DNA ) is the base

ATCG

Enzyme types seen in replication

Unwinding, original, melting, primer, polymerase, remove primers, ligation, untangling

Proofreading

• done by DNA Poly III

• Removal of mismatched base from 3’ end of the growing strand by exonuclease

• Not 100% efficient, but lowers the mutation rate to 10^-9

DNA copies to RNA

Process is called

Transcription and is

performed by an enzyme

complex called an RNA

polymerase

• Synthesis is in a 5’ to 3’

direction

• The RNA is a (near) exact

copy of the plus strand of

DNA

Original,promoter

DNA,rna