RNA TRANSCRIPTION Flashcards
_________________________ is the synthesis of a complementary strand of RNA (called messenger RNA, or mRNA) from a DNA template. An ____ carries the coded information for making a protein. This process proceeds in much the same
fashion as the replication of DNA and also follows the base pairing principle. ___________________ is the key enzyme of RNA transcription that uses a portion of DNA as a template, recognizes and binds to a specific site of DNA called “________________” to start transcription.
RNA transcription is the synthesis of a complementary strand of RNA (called messenger RNA, or mRNA) from a
DNA template. An mRNA carries the coded information for making a protein. This process proceeds in much the same
fashion as the replication of DNA and also follows the base pairing principle. RNA polymerase is the key enzyme of RNA
transcription that uses a portion of DNA as a template, recognizes and binds to a specific site of DNA called
“the promoter” to start transcription.
____________________: It is the first step of this process where the enzyme RNA polymerase and cofactors bind
to DNA and unwind it, creating an _________________________. This is a space that grants RNA polymerase access to a single strand of the DNA molecule.
Pre- initiation: It is the first step of this process where the enzyme RNA polymerase and cofactors bind
to DNA and unwind it, creating an initiation bubble. This is a space that grants RNA polymerase
access to a single strand of the DNA molecule.
_______________: This stage occurs where a group of proteins called _________________________ mediate the
binding of RNA polymerase and the initiation of transcription. Only after certain transcription factors are attached to the promoter does the RNA polymerase bind to it. The completed assembly of transcription factors and RNA
polymerase bind to the promoter, forming a ________________________________________.
Initiation: This stage occurs where a group of proteins called transcription factors mediate the
binding of RNA polymerase and the initiation of transcription. Only after certain transcription factors are attached to the promoter does the RNA polymerase bind to it. The completed assembly of transcription factors and RNA
polymerase bind to the promoter, forming a ________________________________________.
______________________________: In this stage, RNA polymerase must clear the promoter once the first bond has been synthesized. Approximately _____ nucleotides must be synthesized before RNA polymerase loses its tendency to slip away and prematurely release the _________________.
Promoter Clearance: In this stage, RNA polymerase must clear the promoter once the first bond has been synthesized. Approximately 23 nucleotides must be synthesized before RNA polymerase loses its
tendency to slip away and prematurely release the RNA transcript.
_______________: In this stage, one strand of the DNA called the ___________________ or
___________________ is used as a template for RNA synthesis. As transcription proceeds, RNA polymerase
traverses the template strand and uses base pairing complementarity with the DNA template to create an RNA copy
Elongation: In this stage, one strand of the DNA called the template strand or non-coding strand is used as a template for RNA synthesis. As transcription proceeds, RNA polymerase traverses the template strand and uses base pairing complementarity with the DNA template to create an RNA copy
_______________: It is the final step of transcription that results in the release of the newly synthesized ____ from the elongation complex.
Termination: It is the final step of transcription that results in the release of the newly synthesized mRNA from the elongation complex.
____________________ is the process by which genetic information is being translated and converted into a protein molecule. This occurs in the _____________ where the tRNA (transfer RNA) molecules are the actual translators that read the genetic code in mRNA and move in a specific amino acid molecule. The genetic code consists of three consecutive bases in the mRNA called the ____________ which specify the sequence of amino acids in the primary structure of proteins. These codons in mRNA are “read” sequentially by __________________ in transfer RNA (tRNA) during protein
synthesis. The mRNA is read in the __________ direction.
RNA translation is the process by which genetic information is being translated and converted into a protein molecule. This occurs in the ribosomes where the tRNA (transfer RNA) molecules are the actual translators that read the genetic code in mRNA and move in a specific amino acid molecule. The genetic code consists of three consecutive bases in the mRNA called the codons which specify the sequence of amino acids in the primary structure of proteins. These codons in mRNA are “read” sequentially by anticodons in transfer RNA (tRNA) during protein synthesis. The mRNA is read in the 5’ to 3’ direction.
_______________: Protein synthesis is actually initiated by the _______ codon on mRNA in the cytoplasm. The
AUG codon signals both the interaction of the ribosome with mRNA and also the tRNA with the anticodons (UAC). The ____ which initiates the protein synthesis has ________________________________ attached. The formyl group is really formic acid converted to an amide using the amino group on methionine
Initiation: Protein synthesis is actually initiated by the AUG codon on mRNA in the cytoplasm. The
AUG codon signals both the interaction of the ribosome with mRNA and also the tRNA with the anticodons (UAC). The tRNA which initiates the protein synthesis has N-formyl-methionine attached. The formyl group is really formic acid converted to an amide using the amino group on methionine
_______________: _______________ of the polypeptide chain begins as various tRNAs read the next codon to translate it into its respective amino acid. The translated amino acids are joined together by ______________ catalyzed by _________ _______________.
Elongation: Elongation of the polypeptide chain begins as various tRNAs read the next codon to translate it into its respective amino acid. The translated amino acids are joined together by peptide bonds catalyzed by peptidyl transferase.
_______________: This stage occurs when the ____________________ (or termination codons) on mRNA is reached, the protein synthesis is terminated. The last amino acid is hydrolyzed from its t-RNA. There are three stop codons: _______, _______ and ________, for which there are no corresponding tRNA molecules. At this time, the peptide chain leaves the ribosome and the N-formyl-methionine that was used to initiate the protein synthesis is also hydrolyzed from the completed peptide. The ribosome is now ready to repeat the synthesis several more times.
Termination: This stage occurs when the stop codons (or termination codons) on mRNA is reached, the protein synthesis is terminated. The last amino acid is hydrolyzed from its t-RNA. There are three stop
codons: UAA, UAG and UGA, for which there are no corresponding tRNA molecules. At this time, the
peptide chain leaves the ribosome and the N-formyl-methionine that was used to initiate the protein synthesis is also hydrolyzed from the completed peptide. The ribosome is now ready to repeat the synthesis several more times.
