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29 Cards in this Set
- Front
- Back
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Gene
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a segment of DNA specifying a protein (via mRNA), a rRNA or a tRNA
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Sequence of Bases in the DNA
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-purines (A&G)
-pyrimidines (T&C) |
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True
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organization of genetic information is more complex in eukaryotes
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Exons
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coding regions
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Introns
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non coding regions
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Primary Transcript
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-both introns/exons are transcribed here
-unprocessed RNA molecule that is the direct product of transcription |
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Polycistronic
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mRNA of prokaryotes that contain more than one coding region
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Complementary and Antiparallel Nature of DNA
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-adenine and thymine pair
-cytosine and guanine pair -one end is free 3'-hydroxy group -one end is 5'-phosphate group |
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Formation of Stem-Loop Structures
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pairing of complementary bases on the same DNA strand
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Super Coiling
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-a solution to pack a large amount of DNA into small cells or viral particles
-known to affect gene expression |
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Topoisomerases
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in prokaryotes, supercoiling is produced by enzymes called....
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Reverse Gyrase
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introduces positive supercoils, and it is found in hyperthermophilic archaea.
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Coding Density
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defined as the percentage of DNA that encodes for proteins, its higher in prokaryotes than in eukaryotes, which have repetitive sequences
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Plasmids
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DNA molecules that exist separately from the chromosome of the cell.
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Transposable Elements
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DNA molecules that exist separately from the chromosome of the cell.
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Mitochondria & Chloroplasts
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contain their own DNA chromosomes.
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Viruses
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contain a genome, either DNA or RNA, that controls their own replication.
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DNA
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Growth always proceeds from the 5´-phosphate to the 3´-hydroxyl end, the 5'-P of the incoming nucleotide being attached to the 3'-OH of the previously added nucleotide
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DNA Polymerase
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-catalyzes the addition reaction of DNA
-requires a primer made of RNA |
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DNA GROWTH
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extension of the DNA occurs continuously on the leading strand but discontinuously on the lagging strand
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DNA polymerase III
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provides proofreading from the 3' --> 5'
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Helicase
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unwinds DNA
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Primase
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participates in primer synthesis (short stretch of RNA)
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DNA Polymerase III
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synthesizes new strand of DNA (main enzyme)
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DNA Polymerase I
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excises RNA primer and fills in gaps
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DNA Ligase
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seals two fragments of DNA together
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Messenger RNA (mRNA)
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contains the genetic information to encode one or
more polypeptides. Its role is at the genetic level, by carrying the genetic information from the DNA. |
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Transfer RNA (tRNA)
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an adaptor molecule used in translation that has
specificity for both a particular amino acid and for one or more codons. Its role is at the functional and structural levels. |
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Ribosomal RNA (rRNA)
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types of RNA found in the ribosome (functional
and structural roles) |
