Term
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Definition
| a direct correspondence between the nucleotide sequence of DNA and the amino acid sequence of a protein |
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Definition
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Term
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Definition
| noncoding regions called intervening sequences |
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Definition
| found in some rRNA genes; self-splicing, can catalyze their own removal |
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Term
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Definition
| present in some protein-encoding genes of mitochondria, chloroplasts, and a few eubacteria; also self-splicing |
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Term
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Definition
| include introns located in the protein-encoding genes of the eukaryotic nucleus |
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Definition
| found in tRNA genes; utilize another splicing mechanism that relies on enzymes to cut and reseal the RNA |
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Term
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Definition
| a set of 3 nucleotides that encode an amino acid |
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Term
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Definition
| a sequence of nucleotides at the 5' end of the mRNA, does not encode any of the amino acids of a protein |
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Definition
| serves as the ribosomes binding site during translation |
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Term
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Definition
| comprises the codons that specify the amino acid sequence of the protein |
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Definition
| a sequence of nucleotides that is at the 3' end of the mRNA and not translated into protein |
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Term
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Definition
| consists of the addition of an extra nucleotide at the 5' end of the mRNA and the methylation by the addition of a methyl group (CH3) to the base in the newly added nucleotide and to the 2'-OH group of the sugar of one or more nucleotides at the 5' end |
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Term
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Definition
| the addition of 50 to 250 adenine nucleotides at the 3' end of mRNA |
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Term
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Definition
| the process of removing introns from mRNA |
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Term
| 5' Splice Site & 3' Splice Site |
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Definition
| splice sites possessing short consensus sequences; usually beginning with GU and ending with AG |
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Term
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Definition
| an adenine nucleotide that lies from 18 to 40 nucleotides upstream of the 3' splice site |
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Term
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Definition
| consists of 5 RNA molecules and almost 300 proteins; one of the largest and most complex molecular complexes |
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Term
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Definition
| the structure formed when an intron folds back on itself during splicing |
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Term
| Alternative Processing Pathways |
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Definition
| a single pre-mRNA is processed in different ways to produce alternative types of mRNA, resulting in the production of different proteins from the same DNA sequence |
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Term
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Definition
| the same pre-mRNA can be spliced in more than one way to yield multiple mRNAs that are translated into different amino acid sequences and thus different proteins |
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Term
| Multiple 3' Cleavage Sites |
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Definition
| two or more potential sites for cleavage and polyadenylation present in pre-mRNA |
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Term
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Definition
| the coding sequences of an mRNA molecule is altered after transcription and so the protein has an amino acid sequence that differs from that encoded by the gene |
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Term
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Definition
| (gRNAs) contain sequences that are partly complementary to segments of the pre-edited RNA and the two molecules undergo base pairing in these sequences |
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Term
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Definition
| tRNAs have additional bases, including ribothymine, pseudouridine, and dozens of others |
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Term
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Definition
| makes the changes in the bases after transcription to make the various modified bases |
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Term
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Definition
| pairs with the corresponding codon on mRNA to ensure that the amino acids like in the correct order |
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Term
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Definition
in bacteria: 50S
in eucaryotes: 80S |
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Term
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Definition
in bacteria: 30S
in eukaryotes: 40S |
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Term
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Definition
| (RNAi) a powerful and precise mechanism used by eukaryotic cells to limit the invasion of foreign genes (from viruses and transposons) and to censor the expression of their own genes |
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Term
| RNA-Induced Silencing Complex |
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Definition
| (RISC) pairs with an mRNA molecule that possesses a sequence complementary to its siRNA or miRNA component and either cleaves the mRNA, leading to degradation, or represses translation of the mRNA |
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Term
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Definition
| nutritionally deficient mutants |
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Term
| One Gene-One Enzyme Hypothesis |
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Definition
| genes function by encoding enzymes and each gene encodes a separate enzyme |
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Term
| One Gene- One Polypeptide Hypothesis |
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Definition
| when research findings showed that some proteins are composed of more than one polypeptide chain and that different polypeptide chains are encoded by separate genes, the one gene-one enzyme hypothesis was modified to this |
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Term
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Definition
| the building blocks of proteins |
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Term
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Definition
| the type of bond that joins amino acids together |
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Term
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Definition
| comprised of many amino acids joined via peptide bonds |
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Definition
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Definition
| interactions between amino acids causing folding into an alpha helix |
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Term
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Definition
| a secondary folding of the secondary structure |
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Term
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Definition
| the association of two or more polypeptide chains |
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Term
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Definition
| encodes amino acids; 61 of the possible 64 |
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Term
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Definition
| multiple physical states that have equivalent meaning; in terms of multiple codons per amino acid |
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Term
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Definition
| codons that specify the same amino acid |
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Term
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Definition
| different tRNAs that accept the same amino acid but have different anti-codons |
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Term
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Definition
| the third base in a codon bonds weakly; nonstandard pairings of the bases could occur at the 3ed position of the codon |
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Term
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Definition
| codons within the same gene do not overlap; early studies of the genetic code indicated this |
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Term
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Definition
| each different way of reading the nucleotide sequence; there are 3 different possibilities: (e.g.) CAT- ATC- TCA |
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Term
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Definition
| the reading frame is set by this code, the first codon of mRNA- always AUG |
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Term
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Definition
| AKA: termination codons OR nonsense codons: UAA, UAG, and UGA do not encode for amino acids, therefore signal the end of the protein |
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Term
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Definition
| a set of enzymes that specifies between an amino acid and its tRNA (one for each amino acid) |
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Term
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Definition
| the attachment of a tRNA to its appropriate amino acid- requires energy via ATP |
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Term
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Definition
| (IF-3) binds to the small ribosomal subunit and prevents the large subunit from binding during initiation |
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Term
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Definition
| (IF-2) corms a complex with GTP- the initiator tRNA, fMet-tRNA^fMet attaches to the initaion codon via this |
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Term
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Definition
| the initiation complex including 1) small ribosomal subunit 2) mRNA 3) initiator tRNA with amino acid 4) one GTP 5) several initiation factors |
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Term
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Definition
| when the large ribosomal subunit has joined the initiation complex, it is called this |
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Term
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Definition
| AKA; A-site- the enter site of nucleotides within the ribosome |
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Term
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Definition
| AKA: P-site; the site in which the incoming nucleotide forms a peptide bond with the amino acid chain synthesized by the ribosome |
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Term
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Definition
| AKA: E-site; the site where the empty tRNA leaves the ribosome to be reused |
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Term
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Definition
| (EF-Ts) regenerates EF-TU to EF-Tu-GTP- enables the tRNA to attach to a new nucleotide after leaving the A-site |
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Term
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Definition
| (EF-Tu) joins with GTP and then with a charged tRNA to form a three-part complex |
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Term
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Definition
| the movement of the ribosome down the mRNA in the 5' to 3' direction |
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Term
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Definition
| (EF-G) along with the hydrolysis of GTP to GDP, this helps move the ribosome down the mRNA sequence |
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Term
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Definition
| binds to the protein in the absence of a tRNA nucleotide to indicate the completion of the protein |
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Term
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Definition
| an mRNA with several ribosomes attached |
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Term
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Definition
| several mechanisms that exit to detect and deal with errors in mRNAs that may create problems in the course of translation |
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Term
| Non-Sense Mediated mRNA Decay |
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Definition
| prevents the synthesis of aberrant proteins resulting from nonsense mutations within eukaryotic cells- results in the rapid elimination of mRNA containing premature termination codons |
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Term
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Definition
| a molecule tow-truck to deal with stalled ribosomes; contains properties of bother tRNA and mRNA (tmRNA); acts as surrogate tRNA |
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Term
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Definition
| results in the rapid degradation of abnormal mRNA (i.e. mRNA that lacks a stop codon but otherwise creates a normal protein); degrades the mRNA from its 3' end |
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Term
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Definition
| the folding of some proteins requires these molecules in order to be functional (only used when the folding sequence is not automatic) |
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Term
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Definition
| a modification of some proteins involving the removal of 15 to 30 amino acids at the amino end of the protein |
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Term
| Semi-Conservative Replication |
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Definition
| each of the original nucleotide strands remains in tact despite no longer being combined in the same molecule; the original DNA molecule is half (semi) conserved during replication |
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Term
| Equilibrium Density Gradient Centrifugation |
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Definition
| a centrifuge tube is filled with a heavy salt solution and a substance of which the density is to be measured (DNA fragments) |
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Term
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Definition
| individual units of replication |
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Term
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Definition
| each replicon contains this, where replication begins |
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Term
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Definition
| a common type of replication that takes place in circular DNA because it generates a structure that resembles the Greek letter theta θ |
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Term
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Definition
| the unwinding of the double helix generates a loop |
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Term
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Definition
| the point of unwinding, where the two single nucleotide strands separate |
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Term
| Bidirectional Replication |
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Definition
| if there are two replication forks, one at each end of the replication bubble, the forks proceed outward in both directions via this process |
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Term
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Definition
| initiated by a break in one of the nucleotide strands that creates a 3' -OH group and a 5' -phosphate group. New nucleotides are added to the 3' end of the broken strand, with the inner (unbroken) strand used as a template. As new nucleotides are added to the 3' template, rolling out like thread being pulled off a spool. The 3' end grows around the circle, giving rise to the name rolling-circle model |
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Term
| Requirements of Replication |
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Definition
| 1) template consisting of single-stranded DNA 2) raw materials (substrates) to be assembled into a new nucleotide strand 3) enzymes and other proteins that "read" the template and assemble the substrates into a DNA molecule |
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Term
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Definition
| enzymes that synthesize DNA |
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Term
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Definition
| binds to oriC and causes a short section of DNA to unwind |
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Term
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Definition
| breaks the hydrogen bonds that exist between the bases of the two nucleotide strands of a DNA molecule |
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Term
| Single-Stranding Binding Proteins |
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Definition
| attach tightly to the exposed single stranded DNA |
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Term
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Definition
| a topoisomerase: essential for the unwinding process |
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Term
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Definition
| an enzyme that synthesizes short stretches of nucleotides |
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Term
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Definition
| a large multiprotein complex that acts as the main workhorse of replication |
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Term
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Definition
| also has 5' to 3' polymerase and 3' to 5' exonuclease activities permitting the enzyme to synthesize DNA and to correct errors |
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Term
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Definition
| 1) synthesize any sequence specified by the template strand 2) synthesize in the 5' to 3' direction 3) use dNTPs to synthesize new DNA 4) require a primer to initiate synthesis 5) catalyze the formation of a phosphodiester bond by joining the 5' phosphate group of the incoming nucleotide to the 3' -OH group of the preceding nucleotide on the growing strand, cleaving off two phosphates in the process 6) produce newly synthesized strands that are complementary and antiparallel to the template strands 7) associated with a number of other proteins |
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Term
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Definition
| seals the nicks left in the DNA after the RNA primer has been removed and replaced with DNA; catalyzes the formation of phosphodiester bond without adding another nucleotide to the strand |
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Term
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Definition
| most of the errors that do arise in nucleotide selection are corrected in this second process |
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Term
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Definition
| corrects errors after replication is complete; deformities caused during the secondary structure of proteins is recognized by enzymes that replace the incorrect nucleotide |
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Term
| Autonomously Replicating Sequences |
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Definition
| enabled any DNA to which they were attached to replicate |
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Term
| Replication Licensing Factor |
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Definition
| when this attaches to an origin, thus "approving" the replication process |
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Term
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Definition
| contains primase activity, initiates nuclear DNA synthesis by synthesizing and RNA primer, followed by a short string of DNA nucleotides |
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Term
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Definition
| completes replication on the lagging strand |
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Term
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Definition
| takes part in nuclear replication |
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Term
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Definition
| does not participate in replication but is associated with the repair and recombination of nuclear DNA |
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Term
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Definition
| replicates mitochondrial DNA |
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Term
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Definition
| an enzyme with both a protein and an RNA component |
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Term
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Definition
| the exchange of genetic information between homologous DNA molecules |
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Term
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Definition
| a single-stranded DNA molecule of one chromosome pairs with a single-stranded DNA molecule of another, forming this |
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Term
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Definition
| when two homologous chromosomes undergo simultaneous single-strand breaks, causing each strand to criss-cross to the other chromosome, the crossing point is called this. |
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Term
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Definition
| a process of nonreciprocal genetic exchange that can produce abnormal ratios of gametes following meiosis |
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