1. DNA Control Mechanisms
Pre AP Biology
DNA Control Mechanisms

2. Francois Jacob (sitting) & Jacques Monod (standing)

3. Polypeptides that make up enzymes for tryptophan synthesis
Operon Regulation
trp operon
Promoter
Promoter
Genes of operon
DNA
trpR
trpE
trpD
trpC
trpB
trpA
Operator
Regulatory
gene
RNA
polymerase
Start codon
Stop codon 3¢
mRNA 5¢
mRNA 5¢ E D C B A
Protein
Inactive
repressor
Polypeptides that make up
enzymes for tryptophan synthesis
Tryptophan absent, repressor inactive, operon on

4. Operon Repressor DNA No RNA made mRNA Protein Active repressor
Tryptophan
(corepressor)
Tryptophan present, repressor active, operon off

5. Repressor Regulatory gene Promoter Operator DNA lacl lacZ No RNA made3¢
mRNA
RNA
polymerase 5¢
Active
repressor
Protein
Lactose absent, repressor active, operon off

6. Operon and Inducers lac operon DNA lacl lacZ lacY lacA RNA polymerase3¢
mRNA
mRNA 5¢ 5¢
Permease
Transacetylase
Protein
-Galactosidase
Inactive
repressor
Allolactose
(inducer)
Lactose present, repressor inactive, operon on

7. Transposon - Basic
Insertion sequence 5¢ 3¢ 3¢ 5¢
Inverted
repeat
Transposase gene
Inverted
repeat

8. Chromatin vs. Chromosomes appearance within the cell.

9. DNA Control stages in Protein Synthesis
Signal
NUCLEUS
Chromatin
DNA
Gene available
for transcription
Gene
Transcription
RNA
Exon
Primary transcript
Intro
RNA processing
Tail
Cap
mRNA in nucleus
Transport to cytoplasm
CYTOPLASM
mRNA in cytoplasm
Degradation
of mRNA
Translation
Polypeptide
Cleavage
Chemical modification
Transport to cellular
destination
Active protein
Degradation of protein
Degraded protein

10. Post Translation Control of exons

11. Post translation control How many As on the tail?

12. Chaperonin Protein will stay in the cell

13. RER Protein will leave the cell