Goals: Control of Amount and Activity of Proteins, Which proteins to make, and how much of each to make
Regulating Gene Expression
Most Important Step in * * * : controlling transcription because it comes first, you don't copy a gene unless you need its products (i.e: a protein)
all help recrui RNAase
What enzyme melts DNA?
DNA replication is classified as ****
"Mature" cells lose telomerase, lose DNA each cell cycle >> die when lose too much
these type of cells reactivate telomerase
allows you to make enough DNA to analyze starting from very small samples
Photolyase uses this to fix dimers
Nucleotide Excision Repair
fixes chemical damage
Beadle and Tatum
tested the one gene-one enzyme hypothesis
making RNA copy of a DNA sequence
The process of removing introns and rejoining cut ends.
A mutation occurring when the number of nucleotides inserted or deleted is not a multiple of three, resulting in the improper grouping of the following nucleotides into codons.
Process of inserting DNA from one species into another species to create a transgenic organism.
deciphers the genetic code
decide which amino acid goes on each tRNA
site of protein synthesis
3 PHASES - (1) initiation (2) elongation (3) termination
stop of mRNA synthesis (i.e., transcription) at the terminator site
bind DNA and regulate initiantion of transcription
a segment of DNA containing adjacent genes including structural genes and an operator gene and a regulatory gene
protein that binds to the operator in an operon to switch off transcription
region of DNA that indicates to an enzyme where to bind to make RNA
a gene system whose operator gene and three structural genes control lactose metabolism in E. coli
the place where the promoter isn't active until CAP binds
it blocks transcription if no lactose
it is exerted by means of DNA sequences that are not transcribed
RNA polymerase binding site
recruits RNA polymerase
this scientist demonstrated that proteins are strings of amino acids arranged in a specific order by sequencing insulin
transcription and translation
gene expression includes two processes called
used frameshift mutations to show the code consists of three letter "words" with no punctuation
the tRNA nucleotide sequence that pairs with the mRNA is called -
5' -AUG- 3'
What is the sequnce of anticodon that binds to the mRNA codon 5'-CAU-3'
the ribosomes and translation factors
2 differences in bacteria and eukaryotes show how antibiotics which poison bacterial protein synthesis affect humans
transcription, translation, and DNA replication
(1) all three use a nucleic acid template to decide which component to add next to a growing macromolecule, all three are catalyzed by dumb enzymes which need to be told where to start, all three processes can be separated into initiation and elongation phases, all three processes are regulated by proteins which bind to specific nucleic acid sequences
In eukaryotes , includes the events of capping 5' end and adding a poly A tail to the 3' end
structural motifs employed by regulatory proteins
zinc finger, helix-turn-helix, homeodomain, and leucine zipper are all :
these bind to specific DNA sequences through forming H-bonds with specific comvinations of H-bond donors and acceptors exposed in teh major groove by each base pait
This is exerted by DNA sequences that are not transcribed
trp operon regulation
this happens when the trp operon is only transcribed if [trp] is low because the trp repressor senses the [trp] and binds to the operator when [trp] is high
What will happen to the trp operon (all the time) if you mutate the trp repressor so that it can no longer bind DNA?
Steps: -RNA polyermase binds to the promoter and begins synthesizing the primary transcript using the complementary DNA strand as template -the initiation complex assembles on the core promoter and recruits RNA polymerase -The region of DNA containing the gene and its promoter are located and decompressed -Regulatory proteins bind to specific DNA sequences and assemble an initiation complex
Deletion of a single base near the start of the coding sequence would be lethal or ok for an organism
Many retroviruses cause this because they have added an oncogene from a former host to their genome which they then add to the genome of each new host