How Cells Read the Genome: From DNA to Protein
50 questions available
Questions
What is the name of the principle that describes the flow of genetic information from DNA to RNA (transcription) and from RNA to protein (translation) in all living cells?
View answer and explanationWhat are the two principal chemical differences between RNA and DNA molecules?
View answer and explanationAccording to the text, what is the approximate error rate for RNA polymerase during transcription?
View answer and explanationIn bacterial transcription, what is the primary function of the sigma (σ) factor?
View answer and explanationWhich eukaryotic RNA polymerase is responsible for transcribing the genes for transfer RNA (tRNA), 5S rRNA, and some small RNAs?
View answer and explanationWhat is the first modification that occurs on a eukaryotic pre-mRNA molecule as it is being synthesized by RNA polymerase II?
View answer and explanationDuring the process of pre-mRNA splicing, what is the name of the looped structure formed by the excised intron?
View answer and explanationWhat is the primary catalytic component of the spliceosome, responsible for carrying out the chemical reactions of splicing?
View answer and explanationThe process by which a single gene can produce a set of different but related proteins by splicing the RNA transcript in multiple ways is known as what?
View answer and explanationApproximately how many adenine (A) nucleotides are added to the 3' end of a eukaryotic mRNA by poly-A polymerase to form the poly-A tail?
View answer and explanationWhat is the primary site of ribosome synthesis and assembly in a eukaryotic cell?
View answer and explanationWhat is the term for a group of three consecutive nucleotides in an mRNA molecule that specifies either an amino acid or a stop to translation?
View answer and explanationWhat is the function of transfer RNA (tRNA) molecules in protein synthesis?
View answer and explanationThe phenomenon where a tRNA molecule can base-pair with more than one codon, typically due to a mismatch being tolerated at the third position of the codon, is known as what?
View answer and explanationWhat is the function of aminoacyl-tRNA synthetase enzymes?
View answer and explanationThe ribosome is a large complex primarily composed of what two types of macromolecules?
View answer and explanationWhat are the names of the three binding sites for tRNA molecules within a ribosome?
View answer and explanationThe central reaction of protein synthesis, the formation of a peptide bond, is catalyzed by what component of the ribosome?
View answer and explanationIn eukaryotic translation initiation, what molecule is always carried by the special initiator tRNA?
View answer and explanationWhat signals the termination of translation when it appears in the A site of the ribosome?
View answer and explanationWhat is the name for the large cytoplasmic assemblies made up of several ribosomes that simultaneously translate a single mRNA molecule?
View answer and explanationThe quality-control mechanism that detects and degrades mRNAs containing a premature stop codon, often as a result of a splicing error, is called what?
View answer and explanationWhat is the primary signal that molecular chaperones, such as hsp70, recognize on a misfolded or incompletely folded protein?
View answer and explanationWhat type of molecular chaperone, sometimes called a chaperonin, forms a large, barrel-shaped 'isolation chamber' for the protein folding process?
View answer and explanationWhat small protein is attached in a chain to aberrant proteins to mark them for destruction by the proteasome?
View answer and explanationWhat is the name of the central, hollow cylinder of the proteasome that contains the active sites for proteolysis?
View answer and explanationAccording to the RNA world hypothesis, what dual role did RNA molecules play in primitive cells?
View answer and explanationWhat is the key structural feature of eukaryotic RNA polymerase II that is absent in RNA polymerases I and III, and which is crucial for coordinating capping, splicing, and 3' end processing?
View answer and explanationHow many total possible combinations of three nucleotides (codons) are there in the genetic code, and how many different amino acids are commonly found in proteins?
View answer and explanationDuring the elongation cycle of translation, how many high-energy phosphate bonds are consumed for each amino acid added to a polypeptide chain?
View answer and explanationWhat is the role of guide RNAs, such as snoRNAs, in the processing of precursor ribosomal RNA (rRNA)?
View answer and explanationHow does the ribosome-associated quality control (RQC) system typically handle a ribosome that has stalled at the end of a broken mRNA molecule?
View answer and explanationIn bacteria, what is the role of the Shine-Dalgarno sequence?
View answer and explanationHow many tandem repeats of a seven-amino-acid sequence does the C-terminal domain (CTD) of human RNA polymerase II consist of?
View answer and explanationIn the process of regulated destruction, what is the role of the 19S cap of the proteasome?
View answer and explanationWhat is the approximate rate of translation in a eukaryotic ribosome versus a bacterial ribosome?
View answer and explanationWhen a human cell is not actively dividing, what percentage of its RNA is ribosomal RNA (rRNA)?
View answer and explanationWhich type of noncoding RNA directs the splicing of pre-mRNA to form mRNA?
View answer and explanationWhat does the TATA-binding protein (TBP), a subunit of the general transcription factor TFIID, do upon binding to the TATA box sequence in DNA?
View answer and explanationWhy is the genetic code described as being redundant?
View answer and explanationWhat is the typical length of a tRNA molecule?
View answer and explanationWhich process is NOT a recognized quality-control mechanism used by cells to prevent the translation of damaged or aberrant mRNAs?
View answer and explanationWhat is the primary energy source that drives the conformational changes in elongation factors like EF-Tu and EF-G, and also powers the threading of proteins into the proteasome by AAA proteins?
View answer and explanationWhat is a 'ribozyme'?
View answer and explanationWhat are the key consensus sequences that signal the beginning and end of most introns in human pre-mRNAs?
View answer and explanationIn the four-step elongation cycle of translation, what immediately follows the formation of a new peptide bond in step 2?
View answer and explanationHow do many antibiotics, such as tetracycline and chloramphenicol, function to combat bacterial infections?
View answer and explanationWhy did the existence of introns in eukaryotic genes come as a surprise to scientists in 1977?
View answer and explanationWhat is the primary reason that DNA is a more stable molecule for storing genetic information than RNA?
View answer and explanationApproximately what percentage of the total proteins in a cell do proteasomes constitute?
View answer and explanation