BIO REVIEW, PART FOUR - Biology: Final Exam Review...

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Biology: Final Exam Review Checklist Chapter 17: From Gene to Protein Polyribosome A number of ribosomes can translate a single mRNA molecule simultaneously Polyribosome – string of ribosomes on a single mRNA Once a ribosome moves past the start codon, a second ribosome can attach to the mRNA; thus a  number of ribosomes may trail along one mRNA Found in both prokaryotic and eukaryotic cells Post-translational modifications Translation typically not sufficient to make a functional protein Polypeptide chains undergo modification after the translation process - folding - post translational modifications (attaching sugar, lipids, phosphate) Targeting polypeptides: free ribosomes vs. bound ribosomes Polypeptide synthesis always begins on free ribosome in the cytosol Polypeptide are often targeted to specific locations in cell Signal peptide Signal peptide in growing polypeptide determines location of ribosome Based on sequence of amino acids A sequence of about 20 amino acids a or near the leading (amino) end of the polypeptide Signal-recognition particle (SRP) Protein-RNA complex Recognize and bind signal peptide
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Wonderful world of RNA:  RNA plays multiple roles in the cell functional diversity (how?) hydrogen bonding to other nucleic acid molecules (codons in mRNA complementary base pairs  with anticodons in DNA specific three-dimensional confirmations functional groups that allow it to act as a catalyst mRNA messenger RNA carries information specifying amino acid sequences of proteins from DNA to ribosomes rRNA ribosomal RNA plays catalytic (ribozyme) roles and structural roles in ribosomes tRNA transport RNA serves as adapter molecule in protein synthesis; translates mRNA codons into amino acids snRNA spliceosomes plays structural and catalytic roles in splicesomes, the complexes of protein and RNA that slice  pre-mRNA SRP RNA Signal recognition particles
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Is a component of the signal-recognition particle (SRP), the protein-RNA complex that recognizes  the signal peptides of polypeptides targeted to the ER snoRNA small nucleolar RNA processor RNA aids in processing of pre-rRNA transcripts for ribosome subunit formation in the nucleolus si/miRNA siRNA – small interfering RNA miRNA – micro RNA regulate gene expression Mutations Changes in the genetic material of a cell Point Mutations Changes in just one basepair of a gene Base-pair substitution The replacement of one nucleotide and its partner with another pair of nucleotides Silent mutation No effect on encoded protein/function Codes for the same or a similar amino acid Missense mutation Results in a different amino acid that causes problems Nonsense mutation
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This test prep was uploaded on 04/21/2008 for the course BIO 311C taught by Professor Satasivian during the Fall '08 term at University of Texas at Austin.

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BIO REVIEW, PART FOUR - Biology: Final Exam Review...

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