Chapters 6-10 Flashcards
What can occur if the reading frame in a genetic sequence is not read properly?
The polypeptide could be different or not functional.
It could also cause an inappropriate appearance of an stop codon that can lead to a non functional protein
The______is responsible for assisting in attaching tRNA to Amino acids
Aminocacyl-tRNA Synthetase.
Anticondon
A complementary base to the mRNA attached to an tRNA
True or false a scientist reading a genetic code could be sure it is the correct reading frame even if there is no start codon?
False
Which is most likely to be the correct reading frame from the DNA sequences?
5′UGAUGACUCCUGAGGAGAAGUCUUAAUAU-3′
A. UGA UGA CUC CUG AGG AGA AGU CUU AAU AU
( STOP-STOP-Leu-Leu-Arg-Arg-Ser-Leu-Asn)
B.GAU GAC UCC UGA GGA GAA GUC UUA AUA
(Asp-Asp-Ser-STOP-Gly-Glu-Val-Leu-Ile.)
C. AUG ACU CCU GAG GAG AAG UCU UAA UAU
(Met-Thr-Pro-Glu-Glu-Lys-Ser-STOP-Tyr.)
C. is most likely because the stop Codon is closest to the end. and it beginswith a start codon.
Why is Transcription Related to DNA replication?
Because Transcription require DNA to be unwound and a polymerase reaction to add the appropriate nucleotide substrates.
Which one is incorrect?
A. RNA polymerase 1 transcribe genes that codes for genes.
B. RNA polymerase 2 Transcribe protein coding genes and creates messenger RNA.
C. Rna polymerase 3 transcribe gene that code for transfer RNA.
D. A, B, and C are all correct
E. B and C are both incorrect.
D.
Prokaryotes have how many Polymerase.
One
If a mutation changed the sequence of the -10 box, what would you expect the result to be
If the sequence of the -10 box were changed, sigma would not be able to bind to the promoter region, and transcription would not occur
Describe the three phases of transcription.
During initiation, RNA polymerase and additional factors bind the DNA and unwind it to access the template strand of DNA. During elongation, RNA polymerase adds monomers to the growing RNA strand. Termination is the disruption of the association between RNA polymerase, the RNA transcript and the DNA template.
Which phases of transcription could be affected by changes to DNA sequences?
Termination and Initiation can both effected.
During translation the first 20-40 nucleotides of Pre mRNA are sythesizes WHY?
Because the ends of the mRNA are being modified for a modified Guanine nucleotide can be add to the end of the 5’ end. This helps it binds to ribsomes
What is added to the 3’ end of the Pre-mRNA that aids in transport of mRNA to the cytoplasm.
Poly(A) Tail
The mRNA molecule that are included in the final are called…..
The extrons
The introns are kept in the final product of mRNA True or False
False introns are removed from the molecule.
Once the pre mRNA is transcribe several———-particles bind to the consensus——–.
small nuclear ribonucleoprotein, sequences.
What is spiceosome?
The spliceosomes cuts the pre-mRNA removes the intron and joins the exons together.
Describe three ways that the RNA transcript is modified prior to translation in eukaryotes.
A 5′ cap and a 3′ poly-A tail are added to the mRNA. The pre-mRNA is spliced to remove the introns. This creates the mature mRNA that is ready for translation.
Some viruses can make DNA from an RNA template. This process is known as
Reverse Replication
What does RNA polyermase 2 synthesize in eukaryotes.
The synthesis of mRNA.
What does polyermase 1 sythesize?
rRNA molecules
Transcription factors
these are protein that bind to specific DNA sequences called regulatory regions.
When a cell interacts with its enviroment what does it activate.?
Transcription Factors
Enzymes
Are catalysts that lower the energy necessary for a reaction to occur.
Alleles are…
Variation of genes/ Alternate form.
