Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Objectives Compare the structure of RNA with that of DNA. Summarize the process of transcription. Relate the role of codons to the sequence of amino acids that results after translation. Outline the major steps of translation.

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Structure of a Nucleotide

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu adenine, uracil, cytosine, guanine adenine, thymine, cytosine, guanine 4 nitrogen base present ribosedeoxyribose Type of sugar single strand double strand # of strands RNADNA Abbreviation stands for… deoxyribonucleic acid ribonucleic acid

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Pairing Between Bases base-pairing rules in DNA –adenine always pairs with a thymine –guanine always pairs with a cytosine –The strictness of base-pairing results in two strands that contain complementary base pairs. base-pairing rules in RNA –adenine always pairs with a uracil –guanine always pairs with a cytosine complementary

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu 3 Types of RNA rRNA – ribosomal RNA; RNA molecules that make up the ribosome protein factories tRNA – transfer RNA; single strand of RNA that contains the anticodon and temporarily carry a specific amino acid on one end mRNA – messenger RNA; a single stranded RNA molecule that contains the codon information to make a protein

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Types of RNA Section 1 From Genes to Proteins Chapter 10

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Codons in mRNA Section 1 From Genes to Proteins Chapter 10

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Ribosomes Section 1 From Genes to Proteins Chapter 10

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu tRNA and Anticodon Section 1 From Genes to Proteins Chapter 10

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Listing of 20 amino acids

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Codes in mRNA 1. CGG 3. AUG 2. UAU 4. UGA possible codon combos: __ x __ x __ = codon = made up of triplets methionine

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu transcription  the instructions for making a protein are transferred from a gene to an messenger RNA molecule DNA  mRNA translation  portion of protein synthesis that takes place at ribosomes and uses the codons in mRNA molecules to specify the sequence of amino acids in protein chains mRNA  protein

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu gene expression  the entire process by which proteins are made based on the information encoded in DNA. aka protein synthesis.

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Transfer of Information from DNA to RNA transcription  1 st step in the making of a protein –takes the information found in a gene in the DNA and transfers it to a molecule of RNA. –transcribe DNA into mRNA RNA polymerase  an enzyme that adds and links complementary RNA nucleotides during transcription, is required.

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu G C A U

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Snapshot of Translation

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Mutations

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Mutations gene rearrangements  mutations that move an entire gene to a new location –Changes in a gene’s position often disrupt the gene’s function because the gene is exposed to new regulatory controls in its new location. Genes sometimes move as part of a transposon. Other times, the portion of the chromosome containing a gene may be rearranged during meiosis.

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu gene rearrangements  mutations that move an entire gene to a new location aka chromosome mutation

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Mutations Mutations that change a gene  gene alterations. 1.point mutation  a single nucleotide changes. A.missense point mutation B.silent point mutation C.nonsense mutation 2.frameshift mutation  reading frame of codon changes or “shift” A.insertion frameshift mutation B.deletion frameshift mutation

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu missense point mutation  occurs when one nitrogen base is substituted for another nitrogen base causing a different amino acid than previously to occur in the protein sequence.

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu silent point mutation  Happens when one base in a codon is changed but both code for the same amino acid. Silent b/c there are more than one codon for each amino acid.

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu nonsense point mutation  A base mutation that creates a new stop codon in place of an amino acid causing a premature stopping of translation

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Mutations Because the genetic message is read as a series of triplet nucleotides, insertions and deletions of one or two nucleotides can upset the triplet groupings. frameshift mutation  A mutation that causes a gene to be read in the wrong three-nucleotide sequence methionine - cysteine cysteine - valine delete

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Insertion frameshift mutation  shifts the reading frame to the right.

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Deletion frameshift mutation  shifts the reading frame to the left.

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Major Types of Mutations

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Types of Gene Mutations