Translation/ Protein Synthesis Flashcards
(23 cards)
Describe the structure of tRNA
transfer RNA act as adapters that select specific AA and hold them into place on a ribosome for their incorporation into protein. This results in a clover like shape and then is compacted again into an L shape.
How does RNA polymerase start transcription?
when it collides with a DNA and slides down the double helix until it encounters a gene region known as a promoter.
What is the gene region known as a promoter?
a region the contains a specific sequence of nucleotides that lie upstream of the starting point for RNA synthesis.
What is mRNA?
messenge RNA that codes for proteins
What is rRNA?
ribosomal RNA form the core of the ribosomal structure and catalyze protein structure.
What is miRNA?
microRNA regulates gene expression
What is non-coding RNA used for?
-used in RNA splicing -telomere maintenance
tRna match _____ to _____ in mRNA.
Amino Acids ; Codons
What is aminoacyl-tRNA? synthetase?
covalently couples each amino acid to its appropriate set of tRNA molecules. This is known as charging!
What is charging in respects to tRNA and amino acids?
charging occurs when correct amino acids are covalently bonded to their tRNA.
What is genetic code?
The rules by which the nucleotide sequence of a gene, through an intermediary mRNA molecule, is translated into the amino acid sequence of a protein.
Explain what a codon is?
Each group of three consecutive nucleotides in RNA , and each codon specifies one amino acid ex. 5’ AGUGCGAGAA(CCA)3’ –Amino (codon)
Explain what an anti-codon is?
a set of three consecutive nucleotides that bind, through base-pairing, to the complementary codon in an mRNA molecule ex. 5’GCGAGUUGGGACU(GAA)ATCGACCA3’-Amino (anticodon)
What two regions of unpaired nucleotides situated at either end of the L-shaped tRNA molecule are crucial to the function of tRNAs in protein synthesis?
codons and anticodons
Comparison of Prokaryotic and Eukaryotic replication:
What transcribes DNA to RNA?
DNA is transcribed into RNA
by the enzyme RNA polymerase.
How is DNA transcribed by RNA Polymerase?
RNA polymerase moves stepwise
along the DNA, unwinding the DNA helix in
front of it. As it progresses, the polymerase
adds ribonucleotides one by one to the
RNA chain, using an exposed DNA strand as
a template. The resulting RNA transcript is
thus single-stranded and complementary to
this template strand. As the polymerase moves along the DNA template, it displaces the newly formed RNA, allowing the two strands of DNA behind the polymerase to rewind. A short region of hybrid DNA/RNA helix therefore forms only transiently, causing a “window” of DNA/RNA helix to move along the DNA with the polymerase
DNA is transcribed to RNA how:
(with diagram)
An Exion is:
are usually shorter than the introns, and they often represent only a small fraction of the total length of the gene
An Intron is:
a noncoding segment in a length of DNA that interrupts a gene-coding sequence or nontranslated sequence, the corresponding segment being removed from the RNA copy before transcription.
What is a 3’ Untranslated region?
A region of the DNA which IS transcribed into mRNA and becomes the 3’ end or the message, but which does not contain protein coding sequence. Everything between the stop codon and the polyA tail is considered to be 3’ untranslated
What is a 5’ Untranslated region?
A region of a gene which IS transcribed into mRNA, becoming the 5’ end of the message, but which does not contain protein coding sequence. The 5’-untranslated region is the portion of the DNA starting from the cap site and extending to the base just before the ATG translation initiation codon
What is a terminator?
is where the polymerase halts and releases both the DNA template and the newly made RNA transcript. This terminator sequence is contained within the gene and is transcribed into the 3’ end of the newly made RNA.
