DNA Structure & Replication
This specific protein prevents single-stranded DNA from reannealing during replication.
What are single-strand binding proteins (SSBPs)?
This term describes the group of proteins required for RNA polymerase to bind to the promoter in eukaryotic transcription.
What are general transcription factors?
In translation, what is the function of mRNA, and how does it direct the synthesis of proteins?
What is mRNA carries the genetic code from DNA to the ribosome, where it is translated into a specific amino acid sequence to form a protein?
This type of chromosomal mutation occurs when a section of one chromosome is moved to a non-homologous chromosome.
What is a translocation?
The enzyme Taq polymerase is commonly used in PCR. What is the primary reason Taq polymerase is preferred over other DNA polymerases?
What is its ability to withstand high temperatures, as it is heat-stable?
A mutation in helicase prevents it from unwinding the DNA strands. What specific step of DNA replication is directly affected, and what is the consequence?
What is the initiation of replication, resulting in replication forks failing to form?
During transcription, RNA polymerase synthesizes RNA in the 5' to 3' direction. How does the template strand of DNA compare to the RNA transcript in terms of sequence?
What is the RNA transcript is complementary to the template DNA strand, and it has the same sequence as the coding (non-template) strand, except with uracil (U) instead of thymine (T)?
What is the role of release factors in the termination of translation?
What is release factors bind to the stop codon on the mRNA, causing the ribosome to release the completed polypeptide and dissociate from the mRNA?
Both the lac and trp operons use this type of protein to regulate transcription by binding to the operator sequence.
What is a repressor?
The sequence of the DNA is read in this direction from the gel or chromatogram generated during Sanger sequencing.
What is 5' to 3'?
DNA replication occurs in the 5' to 3' direction because DNA polymerase can only add nucleotides to this specific group on the growing strand.
What is the 3'-OH group?
How does a mutation in the spliceosome affect transcription and RNA processing?
What is a mutation in the spliceosome can lead to improper splicing, which may result in the retention of introns or incorrect exon joining, leading to the production of a faulty or nonfunctional protein?
What happens during the initiation phase of translation in both prokaryotic and eukaryotic cells?
What is the ribosome assembles at the start codon (AUG) of the mRNA, and the first tRNA, carrying methionine, binds to the mRNA, initiating protein synthesis?
When glucose levels are low, this molecule binds to CAP (catabolite activator protein) to increase transcription of the lac operon.
What is cAMP (cyclic AMP)?
In recombinant DNA technology, how can a researcher select for bacterial cells that have successfully incorporated recombinant DNA into their genome?
What is by using a selectable marker, such as antibiotic resistance, and growing the cells on selective media?
A mutation in DNA primase prevents it from synthesizing RNA primers. How does this mutation affect DNA polymerase activity?
What is the inability of DNA polymerase to initiate DNA synthesis, as it requires a primer with a 3'-OH group?
How does a mutation that causes a premature stop codon in a gene affect transcription and translation?
What is a premature stop codon may lead to a truncated mRNA transcript that results in the synthesis of a nonfunctional or incomplete protein, potentially causing disease?
What is the mechanism by which elongation occurs during translation?
What is elongation occurs as the ribosome moves along the mRNA, adding one amino acid at a time by matching codons with tRNA anticodons and forming peptide bonds?
A mutation leads to an overactive adenylate cyclase enzyme that produces cAMP regardless of glucose levels. How does this affect the lac operon?
What is constant activation of transcription, provided lactose is present?
In a DNA fingerprinting experiment, a sample is separated on a gel, but the bands are too faint to detect clearly. What can be done to improve band intensity for better visualization?
What is increasing the amount of DNA loaded, using a more sensitive staining method, or optimizing the gel running conditions?
DNA melting temperature (Tm) increases with higher GC content. Explain why this occurs.
What is the stronger hydrogen bonding (three bonds) between G and C compared to A and T (two bonds)?
What is the impact of a defective poly-A-polymerase on mRNA processing in eukaryotic cells?
What is a defective poly-A-polymerase may result in the failure to add a poly-A tail to the mRNA, which can lead to mRNA instability and reduced translation efficiency?
Convert the DNA sequence 3'-ATG TTC CAA GTC-5' to the corresponding mRNA and then to an amino acid sequence.
What is the mRNA sequence 5'-AUG AAG GUU CAG-3', which codes for the amino acid sequence Methionine-Lysine-Valine-Glutamine?
A double mutation in the lacZ and lacI genes leads to a nonfunctional β-galactosidase and a defective repressor that cannot bind the operator. What is the net effect on lactose metabolism and operon transcription?
What is constitutive transcription of the lac operon, but no lactose metabolism due to nonfunctional β-galactosidase?
In Sanger sequencing, the use of ddNTPs (like ddTTP) results in termination at the position of the complementary A base. How can this information be used to reconstruct the original sequence?
What is by analyzing the fragment lengths and matching them with their complementary bases, the sequence of the template can be deduced by reading the bands in order from shortest to longest?