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DNA Deoxyribonucleic Acid “The Blueprint of Life”

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					           DNA
Deoxyribonucleic
           Acid
  “The Blueprint of
                Life”
   I. DNA Structure &
             Function
A. What is DNA?
1. Organic
molecule

2. Nucleic
acid
B.Where is it
  located?
 1. Nucleus
                  DNA
 2. Chromosomes
Chromosomes in
Nucleus
  C. Structure of DNA
1. Nucleotides
   a. Phosphoric Acid
   b. Deoxyribose sugar
   c. Nitrogenous bases:
     Adenine-Thymine
     Guanine-Cytosine
2. Ladder Shape
3. Double strand, helix
   twist
    Ladder Shape (Sides &
    Rungs)
                          Sugar
Sides:                    Acid
• Phosphoric Acid   T-A   Sugar
• Sugar             G-C   Acid
• Phosphoric Acid   C-G   Sugar
Rungs:              A-T
•   A-T
•   T-A
•   G-C
•   C-G
Watson & Crick’s Double
helix:
D. What is DNA’s
Function?
             • Hereditary
               Instructions
             • Chemical
               code for
               every trait
             • “Blueprint”
               for making
               Proteins
Chromosome DNA Code:

Genes =            Hair
                   Color
• Segments
  of DNA
• Code for a       Eye
  trait            Color
    DNA Chromosome
    Code:
Acid      Acid
Sugar-T-A-Sugar
                  Triplets=
Acid       Acid
Sugar-G-C-Sugar   • Sets of 3
Acid       Acid
Sugar-C-G-Sugar     Nucleotides
                  • Code for
                    Trait
 DNA Chromosome Code:
Like Morse Code: Hair   *** *- ** *-*
=                           Or DNA

                            A-T
                            A-T
                            G-C
                            C-G
                            T-A
                            C-G
 DNA Replication
• Chromosomes
  double
• Mitosis
• Late Interphase        2N

• 2n to 4n          2N
  E. Steps for DNA
  Replication:
1. DNA untwists
2. DNA unzips
3. Corresponding base pairs
     Line up
     In sets of 3
     nucleotides (triplets)
     Or “codons”
4. DNA reforms
5. 2 strands twist into helix   Identical
                                Strand
RNA Ribonucleic
          Acid
“DNA messenger
        & taxi”
II. RNA Structure & Function
 A. What is RNA?
1. Organic
   Molecule
2. Nucleic Acid
3. mRNA=
  messenger
   tRNA=
   transfer
  B.Where is RNA
  located?
1. mRNA in
   nucleus &
                   mRNA
   cytoplasm
2. tRNA only       mRNA
   in
   cytoplasm   tRNA
    B. What is RNA’s structure?
                 1. Nucleotides=
•   Acid            a. Phosphoric Acid
•   Sugar-Base      b. Ribose sugar
•   Acid            c. Nitrogenous
•   Sugar-Base         Bases:
•   Acid             Adenine-Uracil
•   Sugar-Base      Guanine-Cytocine
•   Acid         2. Single Strand
•   Sugar-Base   3. No Twisted helix
Comparison of RNA &
DNA:
• Acid           Acid      Acid
• Sugar-Base
        Uracil   Sugar-Base-Sugar
                      Thymine
• Acid
                 Acid      Acid
• Sugar-Base
                 Sugar-Base-Sugar
• Acid
• Sugar-Base     Acid       Acid
• Acid           Sugar-Base-Sugar
                 Deoxy-
                 ribose
•Ribose
   Sugar-Base    Acid      Acid
  RNA               DNA Ladder
 D. What are RNA’s
 functions:

1. mRNA=
• Copies the
   DNA code
• Deliveries
   message to
   Ribosome
• Protein
   Factories
Why not send the
original DNA code out?
• DNA might be     Original DNA
  damaged!
• mRNA
  components are      mRNA copy
  reused
• To copy more
  messages
 RNA function cont.
       Amino   2. tRNA:
       acid    • in cytoplasm
               • Picks up an
                 amino acid
               • “Taxis” the
tRNA             aa to the
                 Ribosome
                 protein
                 factories
 III. Protein
  Synthesis
Assembling Proteins
     from the DNA
       Instructions
  A. Transcription:
1. mRNA is copied
   off of DNA
2. In nucleus
3. Steps:
• DNA untwists
• DNA unzips
• RNA codons line
   up
  Transcription:
                  mRNA has:
           mRNA   • Ribose
    A               sugar
           U      • Uracil
    T               instead of
           A        thymine
    C
           G        bases
    G             • Nuclear
           C        membrane
DNA Code            allows it to
                    leave!
B. Translation =
              • Conversion of
                the message
                (mRNA Code)
              • Into a protein
              • By the
                ribosome
                factories
                        tRNA taxi
 B.Translation
                        A
1. mRNA arrives at
   the Ribosome
2. tRNA picks up an     U
   amino acid
3. tRNA delivers the
   aa to the ribosome               C
4. aa are assembled                     G
   into polypeptide
   proteins
                        U A G C
                         mRNA code
  Summary:
DNA Replication:       Protein Synthesis:
• Make duplicate DNA   1. Transcrition:
• In nucleus           • Make mRNA
• Copy the             • From DNA
  chromosomes          2. Translation:
• For Mitosis          • Make protein
                       • Off mRNA code
                       • Using amino acids

				
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posted:7/28/2012
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