Deja Review USMLE 1 Flashcards
Which nucleotide bases are purines and which are pyrimidines?
“CUT the PY”
Cytosine, Uracil and Thymine = pyrimidines
“PURE as gold (AG)”
Adenine and Guanine are Purines
Which proteins make up the core of the nucleosome?
Histones: H2A, H2B, H3 and H4
Which proteins are associated with DNA between nucleosomes?
Histone H1
Name the mutation described:
Type of mutation that does not result in a change in amino acid sequence.
Silent
Name the mutation described:
Type of mutation that results in a change of amino acid sequence
Missense
Name the mutation described:
Type of mutation that results in a stop codon
Nonsense “no sense”
Name the mutation described:
Type of mutation that changes the reading frame
Frameshift
Name the mutation described:
Type of mutation in which a portion of the DNA is lost
Deletion
Name the mutation described:
Type of mutation in which as single base is exchanged.
Point
Name the type of cytogenetic disorder described below:
Failure of chromosomes to disjoin properly during cell division.
Nondisjunction
Name the type of cytogenetic disorder described below:
Loss of a portion of a chromosome
Deletion
Name the type of cytogenetic disorder described below:
Two internal chromosomal breaks with inverted reincorporation of a portion of the chromosome
Inversion
Name the type of cytogenetic disorder described below:
Single breaks in two chromosomes resulting in the exchange of segments between chromosomes without loss of genetic material
Balanced reciprocal transcription
Name the type of cytogenetic disorder described below:
Single breaks in two acrocentric chromosomes resulting in one large chromosome and one small chromosome accompanied by the loss of some genetic information
Robertsonian translocation
Name the type of cytogenetic disorder described below:
Mitotic error in early development leading to the development of two karyotypically distinct populations of cells in an organism.
Mosaicisim
What term is used to describe the AT-rich sequences in the genome where DNA replication begins
Origin of replication
Name the protein(s) involved in replication or DNA repair with the functions listed below:
Stabilize single stranded DNA
Single stranded DNA binding proteins
Name the protein(s) involved in replication or DNA repair with the functions listed below:
Recognition of AT-rich sequences at the origin of replication and separation of DNA strands.
DnaA protein
Name the protein(s) involved in replication or DNA repair with the functions listed below:
Unwinding DNA double helix
DNA helicase
Name the protein(s) involved in replication or DNA repair with the functions listed below:
Prevention of supercoiling during replication.
DNA topoisomerases
Name the protein(s) involved in replication or DNA repair with the functions listed below:
Placement of RNA primer at site where replication is initiated.
Primase, and an RNA polymerase
Name the protein(s) involved in replication or DNA repair with the functions listed below:
Removal of RNA primers from DNA synthesized discontinuously.
DNA polymerase I (specifically the 5’-3’ exonuclease activity)
Name the protein(s) involved in replication or DNA repair with the functions listed below:
DNA chain elongation in prokaryotes.
DNA polymerase III
Name the protein(s) involved in replication or DNA repair with the functions listed below:
Proofreading of newly synthesized DNA strand.
DNA polymerase III (specifically the 3’-5’ exonuclease activity)
Name the protein(s) involved in replication or DNA repair with the functions listed below:
Repair UV damage to DNA
UV-specific endonuclease, exonuclease, and DNA ligase
Name the protein(s) involved in replication or DNA repair with the functions listed below:
Removal of damaged bases from DNA
Apurinic or apyrimidinic endonuclease, exonuclease and DNA ligase
What term is used to describe the DNA strand synthesized continuously toward the replication fork?
Leading strand
What term is used to describe the DNA strand synthesized discontinuously away from the replication fork?
Lagging strand
What are the three stop codons?
UGA, UAA, UAG (U Go Away, U Are Away, U Are Gone)
In which direction are DNA and RNA synthesized?
5’->3’
What is the start codon?
AUG
Name the type of RNA responsible for each of the following functions:
Largest RNA molecule
mRNA
Name the type of RNA responsible for each of the following functions:
Most abundant type of RNA
rRNA
Name the type of RNA responsible for each of the following functions:
Smallest RNA molecule
tRNA
Name the type of RNA responsible for each of the following functions:
Portion of RNA transcript encoding information for protein synthesis
Exons
Name the type of RNA responsible for each of the following functions:
Portion of RNA transcript that is found between sequences of RNA encoding information for protein synthesis
Introns
Name the type of RNA responsible for each of the following functions:
Type of RNA covalently bound to a single amino acid
tRNA
Name the type of RNA responsible for each of the following functions:
Name the term used to describe the region of genomic DNA where RNA polymerase and transcription factors bind to regulate transcription.
Promoter
Name the type of RNA responsible for each of the following functions:
Name the term used to describe the region of genomic DNA where transcription factors bind to enhance transcription.
Enhancer
Name the enzyme responsible for each of the following functions:
Synthesis of mRNA
RNA polymerase II
Name the enzyme responsible for each of the following functions:
Synthesis of rRNA
RNA polymerase I
Name the enzyme responsible for each of the following functions:
Synthesis of tRNA
RNA polymerase III
Name three major regulatory mechanisms of transcription in eukaryotes.
- Regulation by transcription factors at the level of the promoter
- Regulation by histones binding to specific genomic regions
- Regulation of DNA structure (including methylation, gene rearrangement, and amplification)
What genetic stmcture regulates
transcription in prokaryotes?
An operon
Name the elements of an operon responsible for each of the following functions:
Region where proteins bind to regulate transcription
Promoter region
Name the elements of an operon responsible for each of the following functions:
Molecule that binds at the promoter
Operator
Name the elements of an operon responsible for each of the following functions:
Molecule that binds the operator to regulate transcription
Repressor
What are three modifications made to an RNA transcript before it leaves the nucleus?
- 5’ Capping with 7-methylguanosinn
- 3’ Polyadenylation
- Splicing of introns
Which small molecule provides the energy for charging a tRNA with its amino acid?
Adenosine triphosphate (ATP)
Which small molecule provides the energy for binding tRNA to the ribosome and for translocation?
Guanosine triphosphate (GTP)
Which molecules, central to the discipline of molecular biology, recognize and cleave specific sequences of a DNA molecule?
Restriction enzymes
Name the molecular biology technique described below:
Method of separating molecules based on movement through a gel placed in an electric field
Gel electrophoresis
Name the molecular biology technique described below:
Technique for detecting specific DNA sequences using restriction enzymes and a radiolabeled DNA probe
Southern blot
Name the molecular biology technique described below:
Technique for detecting specific RNA sequences using restriction enzymes and a radiolabeled DNA probe
Northern blot
Name the molecular biology technique described below:
Technique for detecting specific protein sequences using radiolabeled antibodies
Western blot
Name the molecular biology technique described below:
A rapid technique for amplifying a specific DNA sequence in vitro
PCR
Name the molecular biology technique described below:
Technique for detecting different alleles at a gene of interest using restriction enzymes
Restriction fragment length polymorphism analysis