Module 4 Flashcards
DNA
Deoxyribonucleic Acid. Contains the genetic information of the cell.
Purines
Double ring structure (A and G).
Pyrimidines
Single ring structure (T, U, and C).
Double Helix
The structure formed by two strands of complementary nucleotides that coil around each other.
Base Stacking
Stabilizing hydrophobic interactions between bases in the same strand of DNA.
RNA
Ribonucleic Acid. A molecule chemically related to DNA, synthesized as a complement to its DNA template, and involved in protein synthesis, among other functions.
Transcription
The synthesis of RNA from a DNA template.
Gene Expression
The production of a functional gene product, such as a protein.
Template Strand
The strand of DNA that is used to synthesize a complementary daughter strand.
Non-Template Strand
The strand of DNA that is not used as a template for RNA synthesis during transcription (it matches the RNA sequence).
RNA Polymerase
The enzyme that builds the chain of mRNA.
5’-3’
The strand that is being synthesize (the direction of synthesis).
3’-5’
The strand that is being used as a template.
Transcriptional Activator Protein
A protein in eukaryotes that binds to a sequence in DNA to enable transcription to begin.
Enhancer
A specific DNA sequence located upstream, downstream, or within a gene that is necessary for transcription.
Promoter
A regulatory region where RNA polymerase and associated proteins bind to the DNA duplex in the process of transcription.
mRNA
Messenger RNA. The RNA molecule that combines with a ribosome to direct protein synthesis. It carries the genetic “message” from the DNA to the ribosome.
RNA Processing
Converts the primary transcript into the finished mRNA which can then be translated by the ribosome.
Polyadenylation
The addition of a long string of consecutive A-bearing ribonucleotides to the 3’ end of the primary transcript.
Alternative Splicing
A process in which primary transcripts from the same gene are spliced in different ways to yield different mRNAs and therefore different protein products.
Nucleotides
A nucleic acid consisting of a 5-carbon sugar, a nitrogen-containing base, and one or more phosphate groups.
Nucleosides
A molecule consisting of a 5-carbon sugar and a nitrogen-containing base.
Phosphodiester Bond
- C - O - PO2 - O - C
Hydrogen Bonding
An electrostatic interaction between a hydrogen atom in one molecule and an electronegative atom in another molecule.
Replication
The process of copying DNA so genetic information can be passed from cell to cell or from an organism to its progeny.
Central Dogma
DNA —> RNA —> Protein
Translation
Synthesis of a polypeptide chain corresponding to the coding sequence present in a molecule of mRNA.
Ribosomes
A complex structure of RNA and protein that synthesizes proteins form amino acids as directed by the sequence of mRNA.
RNA Transcript
The RNA sequence synthesized from a DNA template.
Initiation (Transcription)
RNA polymerase and other proteins are attracted to double-stranded DNA, the DNA strands are separated, and transcription of the template strand begins.
Elongation (Transcription)
RNA polymerase adds nucleotides to the 3’ end.
Termination (Transcription)
RNA polymerase encounters a sequence in the template strand that causes transcription to stop and the RNA transcript to be released.
TATA Box
A DNA sequence present in many promoters in eukaryotes and archaea that serves as a protein-binding site for a key general transcription factor.
Sigma Factor
A protein in bacteria that associates with RNA polymerase that facilitates its binding to specific promoters.
General Transcription Factors
A protein in eukaryotes that binds to the promoter of a gene whose combined action is necessary for transcription.
Primary Transcript
The initial RNA transcript that is synthesized as a complement to the template DNA strand.
Polycistronic mRNA
A single molecule of messenger RNA that is formed by the transcription of a group of functionally related genes located next to one another along bacterial DNA aka one mRNA codes for many different proteins.
5’ Cap
The addition of a 7-methylguanosine to the mRNA.
RNA Splicing
The process of joining exons and removing introns.
Introns
An intervening sequence that is removed from the primary transcript during RNA splicing (the portion of mRNA that doesn’t code for anything).
Exons
A sequence that is left intact in mRNA after RNA splicing and therefore expressed in the protein (the portion of mRNA that codes for proteins).
Frederick Griffith (1928)
Conducted the experiment with mice and bacteria. Live, non-virulent bacteria had no effect as did dead-virulent bacteria but together they killed the mice. The dead-virulent bacteria somehow made the live, non-virulent bacteria deadly.
Oswald Avery, Colin MacLeod, and Maclyn McCarty (1940s)
Took a solution of dead-virulent bacteria and treated it 3 different ways to destroy a specific aspect, the DNA, RNA, and protein. When these solutions were used to treat live, non-virulent bacteria, all of them except the one used with damaged DNA transformed the live, non-virulent bacteria to virulent bacteria.
Erwin Chargaff
A=T and G=C.
Major Groove
The larger of two uneven grooves on the outside of a DNA duplex.
Minor Groove
The smaller of two unequal grooves on the outside of a DNA duplex.
DNA Polymerase
The enzyme that carries out the synthesis of the new strand of DNA.
Mutation
Any heritable change in the genetic material. Result from an error in replication or a mutagen, such as radiation or chemicals.
RNA World Hypothesis
The hypothesis that the earliest organisms relied on RNA for both catalysis and information storage.
Terminator
A DNA sequence at which transcription stops and the transcript is released.
Mediator Complex
A complex of proteins that interacts with the Pol II complex and allows transcription to being.
Poly(A) Tail
The nucleotides added to the 3’ end of the primary transcript by polyadenylation.
Spliceosome
A complex of RNA and protein that catalyzes RNA splicing.
Ribosomal RNA (rRNA)
Noncoding RNA found in all ribosomes that aid in translation.
Nucleolus
A distinct, dense, non-membrane-bound structure within the nucleus that contains the genes and transcripts for ribosomal RNA.
Transfer RNA (tRNA)
Noncoding RNA that carries individual amino acids for use in translation.
Small Nuclear RNA (snRNA)
Noncoding RNA found in eukaryotes and involved in splicing, polyadenylation, and other processes in the nucleus.
microRNA (miRNA)
Small, regulatory RNA molecules that can cleave or destabilize RNA or inhibits its translation.
Small Interfering RNA (siRNA)
A type of small double-stranded regulatory RNA that becomes part of a complex able to cleave and destroy single-stranded RNA with a complementary sequence.
Enzyme Reverse Transcriptase
Catalyzes reverse transcription.
Reverse Transcription
Uses an RNA template for the synthesis of DNA.
Ribonucleotide Triphosphates
ATP, CTP, GTP, and UTP. Used in transcription.
RNA-DNA Duplex
8 base pairs that are attached together in a transcription bubble.
