Alberts, Ch 6 - From DNA to Protein Flashcards
Anticodon
Sequence of three nucleotides in a tRNA molecule that is complementary to a three-nucleotide codon in mRNA molecule
Consensus nucleotide sequence
A summary or average of a large number of individual nucleotide sequences derived by comparing many sequences with the same basic function and tallyingup the most common nucleotides found in that position
DNA supercoiling
Conformation with loops or coils tht DNA adopts in response to superhelical tension, conversely creating various loops or coils in the helis can create such tension
Eukarotic initiation factors (eIF)
Protein that helps oad initiator tRNA on to the ribosome initiating translation
Exon
Segment of eukaryotic gene that consists of a sequence of nucleotides that will be represented in mRNA or final mature RNA molecule, codes for amino acids in protein-coding genes, usually next to introns
Exosome
Large protein complex with an interior richin 3’-to-5’ RNA exonucleases, degrades RNA molecules to produce ribonucleotides
General transcription factor
Any of the proteins whose assembly at all promoters if given gene type is required for the binding and activation of RNA polymerase and initiation of transcription
Genetic code
Set of rules specifying the correspondence between nucleotide triplets in DNA, codons in RNA and amino acids in proteins
Induced fit
Principle for increasing specificity of substrate recognition by proteins and RNAs, in protein synthesis a ribosome/enzyme folds around codon-anticodon interaction and only when match is correct is subsequent reaction allowed to proceed
Initiator tRNA
Special tRNA. That initiates translation, carries amino acid methionine, forming complex Met-tRNAi
Intron
Noncoding region of eukaryotic gene that is transcribed into RNA molecule but is then excised by RNA splicing during production of mature RNA molecule
Kinetic proofreading
Principle for increasing the specificity of catalysis, in synthesis of DNA, RNA and proteins it refers to a time delay that begins with irreversible step and during which incorrect base pairs are more likely to dissociate that correct pairs
Molecular chaperone
Protein that helps guide proper folding of other proteins or helps them avoid misfolding
Messenger RNA (mRNA)
RNA molecule that specifies the amino acid sequence of a protein, produced in eukaryotes by processing of RNA molecule, translated into protein
Noncoding RNA
RNA molecule that is the final product of a gene and does not code for protein, these RNAs serve as enzymatic, structural and regulatory components for a wide variet of processes in the cell
Nonsense-mediated mRNA decay
Mechanism for degrading aberrant mRNAs containing in-frame internal stop codons before they can be translated into protein
Nuclear pore complex (NPC)
Large multiprotein structure forming an aqueous channel through the nuclear envelope that allows selected molecules to move between nucleus and cytoplasm
Promoter
Nucleotide sequence in DNA to which RNA polymerase binds to begin transcription
Proteasome
Large protein complex in cytosol with proteolytic activity that is responsible for degrading proteins that have been marked for destruction by ubiquitylation or some other means
Reading frame
Phase in which nucleotides are read in sets of three to encode a protein, mRNA molecule can be read in any one of three reacing frames, only one of which will give the required protein
Ribosome
Particle composed of rRNAs and ribosomal proteins that catalyze the synthesis of protein using information provided by mRNA
Ribosomal RNA (rRNA)
Aany one of a number of specific RNA molecules that form part of the structure of a ribosome and participate in synthesis of proteins, often distinguished by sedimentation coefficient
Ribozyme
RNA molecule with catalytic activity
RNA polymerase
Enzyme that catalyzes synthesis of RNA molecule on a DNA template from ribonucleoside triphosphate precursors
RNA polymerase II
RNA polymerase that catalyzes the formation of precursor-mRNAs
RNA splicing
Process in which intron sequences are excised from RNA transcripts, major process in nucleus of eukaryotic cells leading to formation of mRNA
RNA world
Hypothesis that early life on Earth was based primarily on RNA molecules that both stored genetic information and catalyzed biochemical reactions
rRNA gene
Gene that specifies ribosomal RNA
Small nuclear RNA (snRNA)
Small RNA molecules that are complexed with proteins to form ribonucleoprotein particles (snRNPs) involved in RNA splicing
Small nucleolar RNA (snoRNA)
Small RNAs found in nucleolus with various functions including guiding the modifications of precursor rRNA
Spliceosome
Large assembly of RNA and protein molecules that performs pre-mRNA splicing in eukaryotic cells
TATA box
Sequence in promoter region of many eukaryotic genes that binds a general transcription factor (TFIID) and hence specifies position at which transcription is initiated
Terminator
Signal in bacterial DNA thathalts transcription, in eukaryotes terminates after cleavageand polyadenylation of newly synthesized RNA
DNA transcription
Copying of one strand of DNA into a complementary RNA sequence by RNA polymerase
Transfer RNA (tRNA)
Set of small RNA molecules used in protein synthesis as an interface between mRNA and amino acids, each type of tRNA molecule is covalently linked to a particular amino acid
Translation
Process by which the sequence of nucleotides in an mRNA molecule directs incorporation of amino acids into protein, occurs on ribosome
Aminoacyl-tRNA synthetase
Enzyme that attaches the correct amino acid to a tRNA molecule to form an aminoacyl-tRNA
