DNA and RNA

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DNA and RNA

• Chapter 12

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Write the information on the slides that show
this symbol or that is this color.
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Nucleic Acids are complex macromolecules composed
of nucleotides that store and transmit genetic
information.
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• Nucleotides are composed of
• A sugar
• A phosphate group
• A nitrogenous base

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Types of Nucleic Acids

• DNA (Deoxyribose Nucleic Acid)
• RNA (Ribose Nucleic Acid)

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DNA is a molecule of nucleic acid that stores and
transfers genetic information.
Nitrogenous Bases Adenine (A) Thymine
(T) Cytosine (C) Guanine (G)
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Chargaffs Rule

• Percentages of guanine and cytosine and
  percentages of adenine and thymine are almost
  equal in any sample of DNA.
• A T and C G

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DNA Replication

• DNA duplicating before a cell divides
• A pairs with T and G pairs with C

In the diagram, the complementary strand would
be GTAGGC
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RNA

• A messenger between DNA and ribosomes
• Decodes the genetic message contained in the
  DNA molecule

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3 Types of RNA

• Messenger RNA (mRNA) - copies information from
  DNA and carries it to the ribosomes in the
  cytoplasm
• Ribosomal RNA (rRNA) - makes up the major part of
  the ribosomes
• Transfer RNA (tRNA) - carries amino acids to the
  ribosomes where the amino acids are joined to
  form a polypeptide

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Transcription

• Information in a DNA molecule is transferred to
  an mRNA molecule (DNA ? RNA).
• Guanine pairs with Cytosine
• Adenine pairs with Uracil
• Thymine pairs with Adenine

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Practice Transcribing DNA
CUAGGA
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Translation

• Decoding mRNA into a chain of amino acids (RNA ?
  proteins)
• Groups of 3 RNA nucleotides, called codons are
  decoded into amino acids

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Translation
Section 12-3
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Translation
Section 12-3
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DNA RNA

• Deoxyribose (sugar)
• Double stranded
• Nitrogenous bases
• Guanine
• Cytosine
• Adenine
• Thymine

• Ribose (sugar)
• Single stranded
• Nitrogenous bases
• Guanine
• Cytosine
• Adenine
• Uracil

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Codon

• Three-nucleotide sequence on mRNA that codes for
  a single amino acid

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The Genetic Code
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The Genetic Code
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Mutation

• Change in a DNA sequence that affects genetic
  information

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Genetic Mutations

• Point Mutations change involving one or a few
  nucleotides
• Substitution of one base for another
• Insertion or deletion of a base
• Frameshift Mutations shifts the reading of the
  genetic message by inserting or deleting a
  mucleotide

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Genetic Mutations Substitutions, Insertions,
Deletions
Section 12-4
Deletion
Substitution
Insertion
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Chromosomal Mutationsinvolve a change in the
number or structure

• Deletion loss of chromosome
• Duplication produce extra copies of parts
• Inversions reverse direction of parts
• Translocations part breaks off and attaches to
  another part

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Chromosomal Mutations
Section 12-4
Deletion
Duplication
Inversion
Translocation