Chapter 17
Protein Synthesis / Gene Expression
Vocabulary: transcription, translation, messenger RNA, transfer RNA, ribosomal RNA, ribosome, primary transcript, genetic code, triplet code, template strand, codon, anticodon, reading frame, RNA polymerase, promoter region, TATA box, RNA processing, RNA splicing, introns, exons, ribozymes, wobble, polyribosomes (polysomes), mutation, point mutation, frameshift mutation base-pair substitution, silent mutation, missense mutation, nonsense mutation, mutagen
Word Roots
anti- = opposite (anticodon: a specialized base triplet on one end of a tRNA molecule that recognizes a particular complementary codon on an mRNA molecule)
exo- = out, outside, without (exon: a coding region of a eukaryotic gene that is expressed)
intro- = within (intron: a noncoding, intervening sequence within a eukaryotic gene)
muta- = change; -gen = producing (mutagen: a physical or chemical agent that causes mutations)
poly- = many (poly-A tail: the modified end of the 3[H11032] end of an mRNA molecule consisting of the addition of some 50 to 250 adenine nucleotides)
trans- = across; -script = write (transcription: the synthesis of RNA on a DNA template)
Terms : Hide Images
| 1179619645 | Concept 17.1: Genes specify proteins via transcription and translation |  | 0 | |
| 1179619646 | gene expression | the process by which DNA directs the synthesis of proteins or, in some cases, just RNAs |  | 1 |
| 1179619647 | transcription | the synthesis of RNA using a DNA template |  | 2 |
| 1179619648 | messenger RNA | a type of RNA, synthesized using a DNA template, that attaches to ribosomes in the cytoplasm and specifies the primary structure of a protein |  | 3 |
| 1179619649 | translation | the synthesis of a polypeptide using the genetic information encoded in an mRNA molecule |  | 4 |
| 1179619650 | ribosome | a complex of rRNA and protein molecules that functions as a site of protein synthesis in the cytoplasm |  | 5 |
| 1179619651 | primary transcript | an initial RNA transcript; also called pre-mRNA when transcribed from a protein-coding gene | 6 | |
| 1179619652 | triplet code | a set of three-nucleotide-long words that specify the amino acids for polypeptide chains | 7 | |
| 1179619653 | template strand | the DNA strand that provides the pattern for ordering the sequence of nucleotides in an RNA transcript | 8 | |
| 1179619654 | codon | a three nucleotide sequence of mRNA that specifies a particular amino acid or termination signal | 9 | |
| 1179619655 | reading frame | on the mRNA, the triplet grouping of ribonucleotides used by the translation machinery during polypeptide synthesis | 10 | |
| 1179619656 | RNA polymerase | an enzyme that links ribonucleotides into a growing RNA chain during transcription | 11 | |
| 1179619657 | promoter | a specific nucleotide sequence in DNA that binds RNA polymerase, positioning it to start transcribing RNA at the appropriate place | 12 | |
| 1179619658 | terminator | a sequence of nucleotides in DNA that marks the end of a gene and signals RNA polymerase to release the newly made RNA molecule and detach from the DNA | 13 | |
| 1179619659 | transcription unit | a region of DNA that is transcribed into an RNA molecule | 14 | |
| 1179619660 | transcription factor | a regulatory protein that binds to DNA and affects transcription of specific genes | 15 | |
| 1179619661 | transcription initiation complex | the completed assembly of transcription factors and RNA polymerase bound to the promoter | 16 | |
| 1179619662 | TATA box | a DNA sequence in eukaryotic promoters crucial in forming the transcription initiation complex | 17 | |
| 1179619663 | RNA processing | modification of RNA transcripts, including splicing out of introns, joining together of exons, and alteration of the 5' and 3' ends | 18 | |
| 1179619664 | 5' cap | a modified form of guanine nucleotide added onto the nucleotide at the 5' end of a pre-mRNA molecule | 19 | |
| 1179619665 | poly A tail | a sequence of 50-250 adenine nucleotides added onto the 3' end of a pre-mRNA molecule | 20 | |
| 1179619666 | RNA splicing | after synthesis of a eukaryotic primary RNA transcript, the removal of portions (introns) of the transcript that will not be included in the mRNA | 21 | |
| 1179619667 | intron | a noncoding, intervening sequence within a primary transcript that is removed from the transcript during RNA processing | 22 | |
| 1179619668 | exon | a sequence within a primary transcript that remains in the RNA after RNA processing | 23 | |
| 1179619669 | spliceosome | a large complex made up of proteins and RNA molecules that splices RNA by interacting with the ends of an RNA intron, releasing the intron and joining the two adjacent exons | 24 | |
| 1179619670 | ribozyme | an RNA molecule that functions as an enzyme, catalyzing reactions during RNA splicing | 25 | |
| 1179619671 | alternative RNA splicing | a type of eukaryotic gene regulation at the RNA-processing level in which different mRNA molecules are produced from the same primary transcript, depending on which RNA segments are treated as exons and which as introns | 26 | |
| 1179619672 | domain | an independently folding part of a protein | 27 | |
| 1179619673 | transfer RNA | an RNA molecule that functions as an interpreter between nucleic acid and protein language by picking up specific amino acids and recognizing the appropriate codons in the mRNA | 28 | |
| 1179619674 | anticodon | a nucleotide triplet at one end of a tRNA molecule that recognizes a particular complementary codon on an mRNA molecule | 29 | |
| 1179619675 | wobble | flexibility in the base-pairing rules in which the nucleotide at the 5' end of a tRNA anticodon can form hydrogen bonds with more than one kind of base in the third position (3' end) of a codon | 30 | |
| 1179619676 | ribosomal RNA | the most abundant type of RNA, which together with proteins makes up ribosomes | 31 | |
| 1179619677 | A site | the place on a ribosome that holds the tRNA carrying the next amino acid to be added to the polypeptide chain | 32 | |
| 1179619678 | P site | the place on a ribosome that holds the tRNA carrying the growing polypeptide chain | 33 | |
| 1179619679 | E site | the place on a ribosome where discharged tRNAs leave the ribosome | 34 | |
| 1179619680 | polyribosome | a group of several ribosomes attached to, and translating, the same messenger RNA molecule | 35 | |
| 1179619681 | signal peptide | a sequence of about 20 amino acids at or near the leading (amino) end of a polypeptide that targets it to the endoplasmic reticulum or other organelles in a eukarytoic cell | 36 | |
| 1179619682 | signal recognition particle | a protein-RNA complex that recognizes a signal peptide as it emerges from a ribosome and helps direct the ribosome to the endoplasmic reticulum (ER) by binding to a receptor protein on the ER | 37 | |
| 1179619683 | mutation | a change in the nucleotide sequence of an organism's DNA, ultimately creating genetic diversity | 38 | |
| 1179619684 | point mutation | a change in a gene at a single nucleotide pair | 39 | |
| 1179619685 | base pair substitution | a type of point mutation where one nucleotide and its partner in the complementary DNA strand are replaced by another pair of nucleotides | 40 | |
| 1179619686 | missense mutation | a base-pair substitution that results in a codon that codes for a different amino acid | 41 | |
| 1179619687 | nonsense mutation | a mutation that changes an amino acid codon to one of the three stop codons, resulting in a shorter and usually nonfunctional protein | 42 | |
| 1179619688 | insertion | a mutation involving the addition of one or more nucleotide pairs to a gene | 43 | |
| 1179619689 | deletion | a mutational loss of one or more nucleotide pairs from a gene | 44 | |
| 1179619690 | frameshift mutation | a mutation occurring when the number of nucleotides inserted or deleted is not a multiple of three, resulting in the improper grouping of the subsequent nucleotides into codons | 45 | |
| 1179619691 | mutagen | a chemical or physical agent that interacts with DNA and causes a mutation | 46 | |
| 1179619692 | aminoacyl-tRNA synthetase | An enzyme that joins each amino acid to the correct tRNA. | 47 | |
| 1179619693 | Word Roots: trans- = across; -script = write (transcription: the synthesis of RNA on a DNA template) | = across; -script = write (transcription: the synthesis of RNA on a DNA template) | 48 | |
| 1179619694 | Word Roots: poly- | = many (poly-A tail: the modified end of the 3[H11032] end of an mRNA molecule consisting of the addition of some 50 to 250 adenine nucleotides) | 49 | |
| 1179619695 | Word Roots: -gen | = producing (mutagen: a physical or chemical agent that causes mutations) | 50 | |
| 1179619696 | Word Roots: muta- | = change; (mutagen: a physical or chemical agent that causes mutations) | 51 | |
| 1179619697 | Word Roots: intro- | = within (intron: a noncoding, intervening sequence within a eukaryotic gene) | 52 | |
| 1179619698 | Word Roots: exo- | = out, outside, without (exon: a coding region of a eukaryotic gene that is expressed) | 53 | |
| 1179619699 | Word Roots: anti- | = opposite (anticodon: a specialized base triplet on one end of a tRNA molecule that recognizes a particular complementary codon on an mRNA molecule) | 54 |
