RNA and Protein Synthesis Flashcards
RNA is a linear polymer of ______ different types of nucleotide subunits linked by _______
four, phosphodiester bonds
transcription requires the activity of ________ in order to copy the DNA sequence into RNA
RNA polymerase
eukaryotes have ______ RNA polymerases that all have the same mechanism of action but recognize different types of _______
three, promoters
RNA polymerase I transcribes ______ RNA and accounts for the _____% of total RNA
ribosomal, 75
RNA polymerase II transcribes DNA into ______ for the use of protein synthesis, accounts for ___% of the total RNA
messenger RNA, 10
RNA polymerase III is used to transcribe _______, accounts for ____% of total RNA
tRNA, 15
during transcription RNA polymerase copies a DNA template in the _______ direction and synthesizes a RNA molecule in the _______ direction
3’ to 5’, 5’ to 3’
a primer is ________ for the synthesis of new chains during transcription
not required
during transcription, a phosphodiester bond forms between the ________ of the ribose and the _______ where pyrophosphate is then cleaved and released as two ______
3’ hydroxyl, nucleotide, phosphate groups
RNA polymerase is ane enzyme that synthesizes RNA from DNA in the ________ direction
5’ to 3’
RNA polymerase uses _______ as a substrate
ribonucleoside triphosphate
RNA polymerase requires a ______ template
DNA
the RNA sequence of a newly synthesized strand is the same as the _____ sequence of DNA besides having U for T
coding
RNA polymerase uses ______ to recognize specific genes
a promoter
the promoter is an asymmetrical DNA sequence that determines where ________
transcription of a gene by RNA polymerase begins
cell type specific transcription factors recruit ________ to specific genes
RNA polymerase
transcription factors are proteins that bind ______ and recruit RNA polymerase
promoter regions
during the initiation step of RNA synthesis the transcription factor recognizes the _______ and guides RNA polymerase
promoter
during the elongation step of RNA synthesis RNA polymerase escapes the promoter and _______ is released
transcription factor
During the termination step of RNA synthesis RNA polymerase dissociates from DNA once it encounters a ______ sequence
stop
the product made by RNA polymerase II contains _____ and ______
exons, introns
exons are regions that are _______ and code for ______
expressed, proteins
introns are regions that are _______ and do not code for _______
not expressed, proteins
During RNA processing, the first step begins with a 7-methyl guanosine cap adding to the ______
5’ end
the capping process of RNA, protects the transcript from _______ and is important for _______
degradation, translation
During RNA processing, the second step is the addition of a poly A tail to the _____
3’ end
the polyadenylation (poly A tail) signal marks the transcription _______ in eukaryotes
termination
the poly A tail prevents RNA ________ and allows transcript to localize to the _______
degradation, cytoplasm
during RNA processing, RNA splicing is the process in which _______ are removed from the pre-mRNA and ______ are spliced together
introns, exons
alternative splicing is the process in which the same pre-mRNA can make different mRNA transcripts using different ______
exon locations
rRNA and a protein make up ______ which are protein synthesis factories
ribosomes
segments of rRNA are transported to the ______ to eventually become the large and small subunits of the ribosome
cytoplasm
tRNA is synthesized by RNA polymerase III in the ______ and then transported into the ______
nucleus, cytoplasm
tRNA molecules are adaptors that carry the _______ to the ribosome where they are assembled into proteins
proper amino acid
the anticodon region on tRNA is _______ to the mRNA that is being read
complementary
a tRNA with the correct amino acid attached to the 3’ end is said to be ______
charged
in prokaryotes, RNA is produced as a single, long transcript that is cleaved to
produce the _____, ______ and ____ ribosomal RNAs.
16S, 23S, 5S
in prokaryotes, ______ is also cleaved from a larger transcript
tRNA
in prokaryotes, _______, one of the cleavage enzymes, is a protein containing an RNA molecule. This
RNA actually catalyzes the cleavage reaction
RNaseP
translation is the process of reading the information in the ______ and translate
into _______ during protein synthesis
mRNA, amino acids
during translation the mRNA s read in the ________ direction
5’ → 3’
during translation, the ribosome scans the mRNA until the _________ is identified and is translated until a _____ is encountered
start codon (AUG), stop codon (UAG, UGA, UAA)
the open reading frame is the portion of RNA that is translated and
spans from the _______ to the ______
start codon, stop codon
The five steps of protein synthesis include
1) Attachment of amino acids to ______
2) Initiation of protein ______
3) Elongation of the ______
4) Termination and release of ______
5) Folding and processing of ______
tRNAs, synthesis, polypeptide, protein, protein
there are 20 aminoacyl tRNA synthetases, one for
each ________, each recognizes a particular _______ and ALL the _______ that carry that amino acid
amino acid, amino acid, tRNAs
aminoacyl tRNA synthetases recognizes tRNA by specific
sequences of ______ on the tRNA
nucleotides
the synthetase catalyzes the formation of ______
that links the correct amino acid to the correct tRNA
ester bond
synthetase ensures that tRNA is correctly ______
charge
during the initiation of protein synthesis
1) the small subunit of the ribosome binds to the _______
2) the 5’ cap on mRNA guides ribosomes alignment with ______
3) the ______ site (AUG-methionine codon) for translation is identified
4) a ______ tRNA is base paired to its codon
5) the large ribosomal subunit aligns itself to the tRNA molecule at the _____ site and forms a
complex with the small subunit
mRNA, mRNA, start, methionine, P
the first step of elongation of a polypeptide starts with amino acyl-tRNA binding in
the _____ site, governed by codon-anticodon
base pairing
A
the second step of elongation of a polypeptide begins when a peptide bond is formed between the amino acid bound
to the tRNA held in the _____ site of the ribosome and the amino acid bound to
the tRNA held in the ____ site of the ribosome.
“P” , “A”
Peptidyl transferase is a
catalytic RNA component of the ribosome during elongation of a polypeptide which carries out the formation of
the _______
peptide bond
the third step of elongation of a polypeptide starts once the amino acids in the P and A sites are joined, the ribosome translocates, moving the growing
peptide chain to the _____ site and allowing the next charged tRNA to align with the mRNA in the _____ site of the ribosome.
P, A
during the termination and release stage of protein synthesis, elongation continues until ribosome encounters one of 3 _____
codons in the mRNA causing polypeptide synthesis to stop (release factors bind to ribosome)
stop
Many ribosomes can simultaneously translate a single mRNA, forming a complex called ______
polyribosome
In eukaryotes, protein synthesis occurs in the ______
cytoplasm
in bacteria, protein synthesis occurs at the bacterial _______.
chromosome
antibiotics work by disrupting bacterial ______ or _______
transcription, translation
Rifampicin, used to treat Tuberculosis, binds bacterial RNA Polymerase to inhibit _______
transcription
tetracyclines, used to treat Lyme disease, bind the ________, to block the binding of the aminoacyl-tRNA to the ribosome
30S ribosomal subunit
The linear array of
amino acids in a newly
synthesized peptide must
be folded into a functional
protein where the ______ will determine the way a protein will fold
into a 3D structure
amino acids
the signal sequences are short amino acid sequences (15-20 a.a.) at the amino terminus of newly
synthesized ______, that direct protein to its proper cellular location and its two main features are ______ and ______ conformation
polypeptides, hydrophobicity, alpha helical
The signal sequence is removed during ______ or when it reaches its ______
transport, cellular location
Proteins are modified by formation of ______ bonds and/or by _______ or
modification of existing carbohydrate chains
disulfide, glycosylation
Proteins are sorted into ______ or transport vesicles which bud off from the trans face of the Golgi
secretory
Unfolded/misfolded proteins can aggregate and do not travel to the
_____ for further processing
golgi
Proteins that do not fold correctly in the RER can cause a problem (a traffic
jam) and leads to _______
endoplasmic reticulum
(ER) stress
protein misfolding diseases include conditions where a protein _____ to fold correctly, is not stable enough to perform its ______ function, fails to be correctly _____, or forms insoluble aggregates that deposit _____
fails, normal, trafficked, toxically
proteins are eliminated by _________ OR _________ pathways
ubiquitin proteasome systems, autophagy/lysosome
Ubiquitin is a small protein (76 aa) that mark proteins to be ______ by
proteases contained within structures called _______
degraded, proteasomes
The Ubiquitin Proteasome system requires ubiquitin activating enzyme ____, ubiquitin conjugating enzyme ____ and ubiquitin protein ligase _____
(E1), (E2), (E3)
Bortezomib is a proteasome ______
which inhibits inflammatory
NFKB pathway by
preventing degradation
of ______ protein in periodontal disease
inhibitor, repressor
