Card Set Information

2012-04-08 16:45:20

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  1. anticodon
    a three-nucleotide sequence on tRNA that recognizes a complementary codon on mRNA
  2. codon
    a three-nucleotide sequence in DNA or mRNA that encodes an amino acid of signifies a stop signal
  3. exon
    sequence of nucleotides on a gene that gets transcribed and translated
  4. gene expression
    two-stage processing of information encoded in DNA to produce proteins
  5. genetic code
    sequence of nucleotides that specifies the amino acid sequence of a protein
  6. intron
    segment of mRNA transcribed from eukaryotic DNA but removed before traslation of mRNA into a prtein
  7. lac operon
    gene system with a promoter, an operator gene, and three structural genes that controle lactose metabolism
  8. messenger RNA(mRNA)
    RNA copy of a gene used as a blue print for the making of a protein during translation
  9. operator
    regin of DNA that controls RNA polymerases access to set of genes with related functions
  10. uracil
    nitrogen-containing base of RNA complementary to adenine when RNA base pairs with RNA
  11. operon
    segment of DNA that controls gene regulation in a set of genes with related functions in prokaryotes
  12. point mutaion
    mutation in which one or just a few nucleotides in a gene are changed
  13. repressor
    protein that binds to the operator in an operon to switch off transcription
  14. ribonucleic acid(RNA)
    a type of nucleic acid involved in protein synthesis
  15. ribosomal RNA(rRNA)
    type of RNA molecule that plays a strutural role in ribosome
  16. RNA polymerase
    enzyme that adds and links complementary RNA nucleotides during transcription
  17. transfer RNA(tRNA)
    RNA molecule that temporarlly caries a specific amino acid to a ribosome during translation
  18. transcription
    stage of protein synthesis in which the infromation in DNA for making a protein is transferred to an RNA molecule
  19. translation
    stage of gene expression in which the information in mRNA is used to make a protein
  20. amino acid
    oranganic molecule that is the building block of proteins
  21. enzyme
    substance that speeds up a chemical reaction
  22. keratin
    protein that makes skin tough and waterproof
  23. amino group
    a functional group formed by the loss of a hydrogen atom from ammonia
  24. carboxyl group
    an organic functional group consisting of a carbon atom double bonded to an oxygen atom & single bonded to a hydroxyl group
  25. peptide bond
    a bond formed between two amino acids--the carboxy group on one of two amino acids forms an amidde with the amino acids forms and amide with the amino group on second amino acid
  26. catalyst
    substance that speeds up a given chemical reaction by lowering its activation engery without itself being used up
  27. hemoglobin
    red protein responsible for transporting oxygen in blood of vertebrates
  28. macromolecule
    a molecule containing a very large number of atoms
  29. what is produced in transcription
  30. where does transcription take place?
    in the nulceus of cell or mRNA is immediately translated if no nucleus
  31. how does transcription happen?
    • takes information found in a gene in the DNA & transfers it to a molecule of RNA
    • step 1: RNA binds to the genes promoter
    • step 2: RNA polymerase then unwinds & separates the two strands of the double helix, exposing the DNA nucleotides
    • step 3: RNA polymerase add & then links complementary RNA nuleotides as it "reads" the gene
  32. where does translation take place?
    under direction of the mRNA on ribosome
  33. what is created in translation
  34. how does the lac operon word
    there is a repressor which sits on the operator part of gene. when lactose is present in the environment that repressors moves and binds to the lactose molecule--will be able to transcribe to produce an enzyme called lactase
  35. how do eukaryote regulate gene expression
    the on-off switch
  36. what are the 3 steps involved in RNA processing?
    role of cap and tail
    • 1. replication
    • 2. transcription
    • 3.translation
    • cap and tail help to prevent degradation of mRNA molecules and help mRNA attatch to the ribosome subunits during the RNA translation
  37. what gives an amino acid its identity
    the functional group R determines the amino acids identity
  38. how many amino acids are there
  39. what determines the primary structure of a protein
    the function of the protein and its 3D shape
  40. what are alpha helixes and beta pleated sheets
    interactions between neighboring amino acids and ther R groups, polypeptides fold into sheets(beta pleated sheets)-ribbon or coil(alpha helix)-spiral
  41. what jobs do proteins have
    • structural proteins: form basic structures of body(hair, skin pigment)
    • funtional proteins: carry out a wide range of proccesses such as recognitaion and transport of molecules
  42. why is polarity important inside chains
    allows molecules with hydrogen to form hydrogen bonds
  43. what is hydrogen bonding
    the reason water molecules are attracted to each other