Week Three:Basic Molecular Biology

Basic Molecular Biology

I.               Vocabulary

a.     Deletion – indel

b.     Polymorphism – no adverse effect

c.      Mutation - effect

II.             Central Dogma

a.     DNA-RNA-Protein

                                               i.     Sugar - 5carbons, one base, 5prime phosphate

                                              ii.     RNA – 2prime oxygen, hydroxyl

                                            iii.     Phosphates – React with 3prime OH

                                            iv.     AT, GC, AU

b.     5prime to 3prime and 3rime to 5prime

                                               i.     Complementary

c.      Replication

                                               i.     5prime to 3prime

                                              ii.     Semiconservative

                                            iii.     DNA polymerase

1.     Leading and lagging

2.     Leading = easy/fast

3.     Lagging lays down primers, slow

III.           Chromosomes

a.     DNA-2nm

b.     Histones – beads on a string

                                               i.     H2A,H2B,H3,H4,H1

c.      30nm string

d.     Supercoiled

IV.            RNA

a.     Transcription

                                               i.     DNA – antisense

                                              ii.     RNA – Sense strand

b.     TRNA

c.      mRNA

d.     rRNA

                                               i.     ribosomes!

1.     2 Subunits

2.     Translation

a.     Initiation

b.     Elongation

c.      Termination

V.              Genes

a.     Definitions

                                               i.     Unit of information

                                              ii.     Transcribed unit of DNA

1.     Some genes regulated through the use of silencers or enhancers

a.     Steroids etc, cross the membrane and bind to receptors in the nucleus

b.     Locus – specific physical location

c.      The Code

                                               i.     Triplets – codons, code for one protein usually

                                              ii.     5prime to the 3prime RNA- N-C terminus in proteins

                                            iii.     4^3 = 64 codons

1.     but…degenerate!

2.     21 amino acids

                                            iv.     SNP – single nucleotide polymorphism

1.     Mutation must have an effect

2.     Often doesn’t

                                              v.     Reading frame shift

1.     Often deleterious