Final Exam Chapter 6 Flashcards
What is the central dogma of molecular biology?
DNA to RNA to Protein
Which enzyme is responsible for transcription?
RNA Polymerase
What is the function of a promoter in transcription?
Recognized by RNA Polymerase for binding
What process involves the removal of introns from pre-mRNA?
Splicing
What is the role of tRNA in translation?
Carries (transfers!) amino acids to the ribosome
What assists in protein folding in the cell?
Chaperones
What is the product of translation?
Protein
Which step of translation involves the addition of amino acids to the growing polypeptide chain?
Elongation
What is the function of a ribosome in translation?
Enhances translation
What is the primary function of proteasome in the cell?
Protein degradation
What is the role of RNA polymerase in transcription?
Synthesizing RNA from DNA
Which of the following is NOT a type of RNA molecule?
DNA
What is the function of a promoter in transcription?
Initiates RNA synthesis
Which process involves the addition of a poly-A tail to mRNA?
3’ End processing
What is the genetic code redundancy?
Each amino acid has multiple codons
Where does translation occur in a eukaryotic cell?
Ribosome
Which molecule carries the anticodon that pairs with mRNA codons during translation?
tRNA
What is the function of chaperones in protein folding?
Assist in correct folding of proteins
Which step of translation involves the movement of ribosome along the mRNA?
Elongation
What is the primary function of the proteasome in the cell?
Protein degradation
What is the function of DNA helicase during DNA replication?
Separates the DNA strands
Which enzyme is responsible for joining Okazaki fragments during DNA replication?
DNA ligase
What is the role of topoisomerase in DNA replication?
Relieves supercoiling ahead of the replication fork
It allows DNA to unwind and spin during replication, ensuring proper replication and preventing tangling.
Which DNA repair mechanism corrects thymine dimers caused by UV radiation?
Nucleotide excision repair
What is the function of DNA polymerase in DNA replication?
Synthesizes new DNA strands
Which enzyme is responsible for RNA primer synthesis during DNA replication?
Primase
What is the function of the sliding clamp in DNA replication?
Helps to keep the DNA polymerase attached to the DNA template during replication.
Increases the processivity of DNA polymerase
Which DNA repair mechanism corrects single-strand breaks in the DNA backbone?
Single-strand break repair
What is the role of DNA ligase in DNA replication
Joins Okazaki fragments
Which enzyme is responsible for removing RNA primers and replacing them with DNA during DNA replication?
DNA polymerase I
What is the function of the replisome in DNA replication?
Coordinates the functions of DNA replication enzymes
Which DNA repair mechanism is involved in repairing double-stranded breaks?
Homologous recombination
What is the function of the origin of replication in DNA replication?
Initiates DNA synthesis
Which enzyme is responsible for proofreading newly synthesized DNA strands during replication?
DNA polymerase III
What is the function of the single-strand binding proteins in DNA replication?
Stabilize single-stranded DNA
Which DNA repair mechanism corrects mismatched bases that result from replication errors?
Mismatch repair
What is the role of the DNA polymerase III holoenzyme in DNA replication?
Acts as the main replicative polymerase
Which enzyme is responsible for removing RNA primers in the lagging strand during DNA replication?
RNase H
What is the function of the DNA polymerase I enzyme in DNA replication?
Removes RNA primers and replaces them with DNA
What is the function of the DNA ligase enzyme in DNA replication?
Joins Okazaki fragments
What is the function of DNA ligase in DNA replication?
Joins Okazaki fragments
What is the function of DNA helicase in DNA replication?
Unwinds the DNA double helix
Which enzyme is responsible for synthesizing RNA primers during DNA replication?
Primase
Explain the process of DNA replication, including the roles of leading and lagging strands.
DNA replication is the process of copying DNA to produce two identical DNA molecules. The leading strand is synthesized continuously, while the lagging strand is synthesized discontinuously in short Okazaki fragments.
SHORT ANSWER: Making two identical DNA copies. Leading made continuously, lagging in short fragments.
Describe the function of DNA polymerase III in DNA replication
DNA polymerase III is the main replicative polymerase that synthesizes the new DNA strand by adding nucleotides in a 5’ to 3’ direction.
SHORT ANSWER: Main enzyme adding nucleotides for new DNA strand.
Discuss the significance of the origin of replication in DNA replication.
The origin of replication is where DNA replication begins and initiates the synthesis of new DNA strands. It serves as the starting point for the replication process.
SHORT ANSWER: Starting point for DNA replication, where synthesis begins.
Explain the role of topoisomerase in DNA replication
Topoisomerase relieves supercoiling ahead of the replication fork by breaking and rejoining DNA strands, allowing the DNA to unwind and replicate properly.
SHORT ANSWER: Relieves DNA supercoiling by unwinding strands for replication.
Describe the function of DNA ligase in DNA replication.
DNA ligase joins Okazaki fragments on the lagging strand by catalyzing the formation of phosphodiester bonds between adjacent nucleotides, ensuring the completion of DNA replication.
SHORT ANSWER: Joins short DNA fragments to complete replication.
Explain the role of DNA helicase in DNA replication.
DNA helicase unwinds the double-stranded DNA helix ahead of the replication fork by breaking hydrogen bonds between base pairs, allowing DNA polymerases to access the separated strands for replication.
SHORT ANSWER: Unwinds DNA strands for replication by breaking hydrogen bonds.
Describe the function of RNA primers in DNA replication.
RNA primers are short sequences of RNA nucleotides that provide a starting point for DNA polymerases to begin synthesizing new DNA strands during replication.
SHORT ANSWER: Starting point for DNA polymerases to make new DNA strands during replication
Discuss the importance of the replisome in coordinating DNA replication.
The replisome is a complex of enzymes and proteins that work together to ensure accurate and efficient DNA replication by coordinating the activities of various enzymes involved in replication.
SHORT ANSWER: Group of enzymes + proteins coordinating accurate DNA replication.
Explain the process of mismatch repair in DNA replication.
Mismatch repair is a mechanism that corrects errors in base pairing that occur during DNA replication by identifying and removing the incorrectly paired nucleotides, followed by re-synthesis of the correct DNA sequence.
SHORT ANSWER: Fixes incorrect base pairs during replication to maintain accuracy.
Describe the function of single-strand break repair in maintaining DNA integrity.
Single-strand break repair mechanisms fix breaks in one of the DNA strands, ensuring the accurate transmission of genetic information and preventing mutations that could lead to diseases or cell death.
SHORT ANSWER: Fixes breaks in one DNA strand to preserve genetic information.
