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Gene regulation
Transcription
Translation
Mutations/Problems
Replication
100
This phenomenon allows bacteria to "communicate" with each other. They can begin to secrete enzymes, signal molecules, or produce colonies as a result of their communication.
Quorum sensing
100
What enzyme initiates DNA transcription?
RNA polymerase
100
UAA, UAG, and UGA are all what?
Stop codons
100
UV light causes what type of DNA mutation
Formation of Thymine Dimers
100
In what directions is DNA ALWAYS replicated (elongated)?
5' to 3'
200
True or false: one of the separated DNA strands in transcription is actually replicated
True
200
What is the purpose of tRNA?
To carry the next amino acid to the ribosome to be added onto the growing peptide chain
200
Nitrous acid and Aflatoxins mutate what aspect of genes?
They chemically change the DNA base pairs
200
What best describes DNA replication: Conservative, Semi-conservative, or Non-conservative
Semiconservative
300
If Bobby is a repressor protein what does he mainly do?
prevents transcription
300
What is the name of the RNA strand being synthesized from DNA? Where will it go after it is completed?
mRNA, the ribosome
300
True or false: there are many ribosomes bound to an mRNA strand all coding for the same protein simultaneously.
True
300
What is the best type of mutation? Why?
A silent mutation (does nothing) or a triplet mutation because changing three base pairs will only change one amino acid and no others. That means that there is a small change this will effect the overall protein being translated
300
Where is the next nucleotide added on the ribose sugar during replication?
The 3 carbon hydroxyl group
400
The Lac operon is an inducible operon, what does this mean?
Is usually off, and can be turned on by CAP, thus allowing for lactose production
400
These regions of DNA right before a gene about to be transcribes bind to RNA polymerases.
Promoters
400
What is the first amino acid (start codon) in every prokaryotic protein?
formylmethionine (fMET)
400
What is the worst type of mutation, why?
Frameshift, every amino acid after the mutation site will be affected
400
Describe what Okazaki fragments are and why they exist?
They are short sequences of replicated DNA that have to be added to the growing lagging strand. This is necessary because when DNA unwinds the lagging strand becomes longer whereas the leading strand is continually "eaten up" by the DNA polymerase.
500
Excess Tryptophan from the environment can bind to Operon Gigi, causing E. Coli to stop synthesizing Tryptophan in the cell. When Operon Gigi is not bound to Tryptophan, Gigi does not prevent E. coli to synthesize Tryptophan. Why might this occur? What is the type of operon that Tryptophan binds to?
If Trp from the environment is in excess then the E. Coli cell can use that extra Trp and does not have to make it's own. This energy saving process is beneficial and helps E. Coli survive. The Gigi operon is called a repressor operon, because it is normally inactive, allowing Tryptophan systhesis. When excess environmental Trp binds to Gigi this stops Trp synthesis.
500
There are regions of DNA after genes that have large GC content and then large A content. What are these called and what do they do?
Terminator sequences, they stop RNA polymerase from transcribing DNA
500
Name the three main "sites" on a ribosome for translating the mRNA strand.
A-site (binds the tRNA delivering the next amino acid) P-site (holds the tRNA and the growing polypeptide) E-site (exit site for tRNA)
500
Describe the process of dark repair
Cut damaged (mutated) section out, fill in the gap with correct nucleotides using DNA polymerase I and DNA ligase
500
What are the 4 main enzymes required for DNA replication? What does each one do?
DNA polymerase - adds nucleotides to the elongating strands Primase - prepares the way for DNA polymerase to bind Ligase - connects the lagging strand Okazaki fragments to continue DNA synthesis Gyrase - relieves steric strain when DNA is unwound for replication