Chapter 17: Gene to Protein Flashcards
What is Gene to Protein?
DNA is transcribed into RNA and RNA is translated into the Protein
Coding region
The actual region of the gene that will be converted into a protein (lies between the promoter and the terminator)
A sequence of DNA in the gene that causes the end of transcription
Terminator
the process by which DNA directs protein synthesis
What is gene expression?
An organism that carries one or more genes from a different species
Transgenic
What are the 3 characteristics of a gene?
Promotor, coding region, terminator
What is the region of a gene that is required for the initiation of transcription?
Promotor
What are the 3 stages of transcription?
- Initiation 2. Elongation 3. Termination
What are transcription facots?
Proteins that recognize the promotor region and bind to the promotor.
What does the cap G do?
Protects the RNA from degrading enzymes and also helps ribosomes recognize attachment sites
What does A tail do?
May inhibit degradation, may help attachment to ribosomes, and may regulate protein synthesis by helping to move the mRNA from the nucleus to the cytoplasm through the nuclear pores.
What is RNA splicing?
The gene that codes for a protein may contain segments that are not used during translation, and thus must be removed.
What is an intron?
Non-coding sections in the DNA of a gene that are initially transcribed but not translated because they are removed first.
What are exons?
coding sections of a gene that are transcribed and translated into a protein.
What is tRNA?
Transfer amino acids from the cytoplasm’s pool to a ribosome
What is aminoacyl tRNA synthetase?
An enzyme that attaches
Why might a point mutation in DNA make a difference in the level of protein’s activity?
It might substitute an amino acid in the active site.
A part of the promoter, called the TATA box, is said to be highly conserved in evolution. Which of the following might this illustrate?
Any mutation in the sequence is selected against
A particular triplet of bases in the template strand of DNA is 5’ AGT 3’. The corresponding codon for the mRNA transcribed is
3’ UCA 5’.
What is the function of the release factor (RF)?
It binds to the stop codon in the A site in place of a tRNA.
The tRNA shown in the figure has its 3’ end projecting beyond its 5’ end. What will occur at this 3’ end?
The amino acid binds covalently
The nitrogenous base adenine is found in all members of which group?
ATP, RNA, and DNA
What is the function of GTP in translation?
GTP energizes the formation of the initiation complex, using initiation factors.
Which of the following statements is true about protein synthesis in prokaryotes?
Translation can begin while transcription is still in progress.
Why might a point mutation in DNA make a difference in the level of protein’s activity?
It might substitute an amino acid in the active site.
What is the function of the release factor (RF)?
It binds to the stop codon in the A site in place of a tRNA.
A part of an mRNA molecule with the following sequence is being read by a ribosome: 5’ CCG-ACG 3’ (mRNA). The following charged transfer RNA molecules (with their anticodons shown in the 3’ to 5’ direction) are available. Two of them can correctly match the mRNA so that a dipeptide can form.
The anticodon loop of the first tRNA that will complement this mRNA is
3’ GGC 5’
Transcription in eukaryotes requires which of the following in addition to RNA polymerase?
several transcription factors (TFs)
Which of the following DNA mutations is the most likely to be damaging to the protein it specifies?
a base-pair deletion
What type of bonding is responsible for maintaining the shape of the tRNA molecule?
hydrogen bonding between base pairs
Which of the following does not occur in prokaryotic eukaryotic gene expression, but does in eukaryotic gene expression?
A poly-A tail is added to the 3’ end of an mRNA and a cap is added to the 5’ end.
Which of the following mutations is most likely to cause a phenotypic change?
a single nucleotide deletion in an exon coding for an active site
A possible sequence of nucleotides in the template strand of DNA that would code for the polypeptide sequence phe-leu-ile-val would be
3’ AAA-GAA-TAA-CAA 5’.
In eukaryotic cells, transcription cannot begin until
several transcription factors have bound to the promoter.