DNA (deoxyribonucleic acid)

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2/9/12-
Ch 12 DNA/RNA vocabulary 1. Nucleotide 2.
Chromatin 3. Replication 4. Gene 5.
Transcription 6. Codon 7. Translation 8.
Anticodon 9. Mutation

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Nucleic Acids and Protein Synthesis
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DNA (deoxyribonucleic acid) is

• An organic compound
• A type of nucleic acid
• Double stranded
• Made up of subunits called NUCLEOTIDES

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Nucleotides have 3 parts

• Sugar molecule called DEOXYRIBOSE
• PHOSPHATE GROUP
• NITROGEN CONTAINING BASE

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THE 4 NITROGEN CONTAINING BASES IN DNA

• ADENINEA
• GUANINEG
• CYTOSINEC
• THYMINET

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PURINES

• ADENINE and GUANINE are PURINES
• Bases that have 2 rings of carbon and nitrogen
  atoms

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PYRIMADINES

• CYTOSINE THYMINE are PYRIMADINES
• Bases that have 1 ring of carbon and nitrogen
  atoms

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WATSON CRICK

• WATSON CRICK suggested that DNA is made of 2
  nucleotide chains that wrap around each other to
  form a spiral shape called a double helix.

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THE COMPLEMENTARY BASE PAIRING RULES

• In a double helix, cytosine pairs with guanine
  adenine pairs with thymine.
• Therefore, AT CG.

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REPLICATION

• The copying of DNA is called REPLICATION.
• The 2 nucleotide chains separate by
  unwinding-each chain serving as a template for a
  new nucleotide chain.
• If the original DNA strand sequence is
  A-T-T-C-C-G, the new nucleotide chain would read
  T-A-A-G-G-C.
• When replication is finished, 2 new exact copies
  of the original DNA molecule are produced the
  cell is ready to undergo cell division.

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DNA Replication
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• A change in a nucleotide sequence is called a
  MUTATION.
• DNA may be damaged by a variety of things, such
  as chemicals and ultraviolet (UV) rays from the
  sun.

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Quick Quiz

• What are the three parts of a nucleotide?
• What is stated by the complimentary base pairing
  rules?
• What is replication?

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2/10/12 Do Now

1. DNA is made of small subunits called _____.
2. Nucleotides have three parts. They are ___, ___,
   ___.
3. The sugar found in DNA is ________.
4. According to Chargaffs Rules (complementary base
   pairing rules), adenine pairs with ____ _____
   pairs with guanine.
5. Purines have ___ ring(s) of carbon nitrogen,
   while pyrimadines have ___ ring(s) of carbon
   nitrogen.
6. The copying of DNA is ______.
7. If the original strand of DNA reads ACTGGCTA, the
   new strand will read _______.
8. Any change in DNA is referred to as a _____.

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9/13/11-Pick up your book.

• Do-Now
• Pick up and complete the DNA Protein Synthesis
  Puzzle.
• Set out your vocab flashcards, DNA color sheet,
  Scientist Graphic Organizer from yesterday.

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RNA (ribonucleic acid) is

• An organic compound
• Type of nucleic acid
• Made up of nucleotides
• Single strand
• THYMINE is rarely part of RNA. URACIL (another
  pyrimadine) replaces thymine in RNA. This means
  that URACIL, not thymine, pairs with ADENINE in
  RNA.
• UA

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Compare RNA to DNA
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Types of RNA (all 3 help to make proteins)

• 1.MESSENGER RNA (mRNA) is made of a single,
  uncoiled chain. mRNA carries genetic info from
  the DNA in the nucleus to the cytosol of a
  eukaryotic cell.

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Types of RNA, cont.

• 2. TRANSFER RNA (tRNA) is a single chain of RNA
  nucleotides folded into a hairpin shape that
  binds to specific amino acids.

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Types of RNA, cont.

• 3. RIBOSOMAL RNA (rRNA) is the most common RNA.
  rRNA is made of RNA nucleotides that are in
  globular form. rRNA makes up the ribosomes where
  proteins are made.

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TRANSCRIPTION

• The process by which genetic info is copied from
  DNA to RNA
• All 3 types of RNA are made in this process
• Continues until the TERMINATION SIGNAL is reached
• Think of using a variety of colored paper in the
  copy machine

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TRANSCRIPTION
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Recall that

• The making of proteins is called PROTEIN
  SYNTHESIS
• PROTEINS are made of AMINO ACIDS that are linked
  together by PEPTIDE BONDS.
• The function of the protein is decided by the
  amino acids that make it up.

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GENETIC CODE

• The relationship between a nucleotide sequence
  and an amino acid sequence is called the GENETIC
  CODE.
• It is used to translate mRNA transcripts into
  proteins.
• The genetic info needed for making proteins is
  encoded in a series of 3 mRNA nucleotides called
  a CODON.

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Genetic Code, cont.

• Each codon codes for a specific amino acid.
• Some codons signal for translation of an mRNA to
  start or stop.
• The START CODON (AUG) makes a ribosome start
  translating an mRNA molecule.
• STOP CODONS (UAA, UAG, UGA) cause the ribosome to
  stop translating the mRNA.

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9/14/11-Pick up your book. Student Summaries
for Sat. School?

• Do-Now
• DNA is made of small subunits called _____.
• Nucleotides have three parts. They are ___, ___,
  ___.
• The sugar found in DNA is ________.
• According to Chargaffs Rules (complementary base
  pairing rules), adenine pairs with ____ _____
  pairs with guanine.
• Purines have ___ ring(s) of carbon nitrogen,
  while pyrimadines have ___ ring(s) of carbon
  nitrogen.
• The copying of DNA is ______.
• If the original strand of DNA reads ACTGGCTA, the
  new strand will read _______ (replication).
• Any change in DNA is referred to as a _____.

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Genetic Code, cont.
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TRANSLATION

• The process of assembling polypeptides from info
  encoded in the mRNA
• Begins when mRNA leaves the nucleus through pores
  in the nuclear membrane
• mRNA migrates to a ribosome where protein
  synthesis takes place

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Translation, cont.
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Translation, cont.

• Amino acids floating in the cytosol are brought
  to the ribosomes by the tRNA molecules
• On the opposite side of the tRNA molecule (from
  where the amino acid is attached), there is a
  loop that has a sequence of 3 nucleotides called
  an ANTICODON.
• The tRNA anticodon is complementary to and pairs
  with its corresponding mRNA codon.
• For example, a tRNA with an anticodon of AAA
  would bind to the mRNA codon sequence of UUU.

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Translation, cont.
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Protein Assembly

• Starts with start codon (AUG)
• As a ribosome moves down an mRNA transcript, each
  mRNA codon is paired with its tRNA anticodon.
• This causes an amino acid to attach, forming a
  peptide bond.
• As each amino acid is added to the chain, the
  ribosome moves 3 nucleotides (1 codon) ahead on
  the mRNA transcript, where the next amino acid
  will be translated.
• It ends with a stop codon.

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• Read p. 307-308

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Practice!

1. DNA replication is taking place. The original
   strand is ACTGCATCA. The new strand will read
   _____.
2. Transcription is taking place. Transcribe your
   DNA (answer) from 1 to make mRNA.
3. Translation is taking place. Translate your mRNA
   (answer) from 2 to determine the amino acid
   sequence. Use the genetic code from your book or
   your notebook.

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9/15/11-Get your book.

• Do-Now
• Copying DNA to make new DNA is called ___.
• Copying DNA to make RNA is called ____.
• Using the information on mRNA to assemble amino
  acids to make proteins is called ___.
• The monomers of DNA RNA are ____.
• The 3 parts of a nucleotide are __, __, __.
• List the 3 types of RNA what they do.

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More Practice!

• DNA replication is taking place. The original
  strand is TAGCATGGGCAT. The new strand will read
  _____.
• Transcription is taking place. Transcribe your
  DNA (answer) from 1 to make mRNA.
• Translation is taking place. Translate your mRNA
  (answer) from 2 to determine the amino acid
  sequence. Use the genetic code from your book or
  your notebook.

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9/28/10-Pick up your book.

• Do-Now
• Complete the crossword puzzle on the back of
  your DNA word search. If you turned this into me,
  I have put it on your desk for you.

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Quick Quiz

• What are two differences between RNA and DNA?
• What is transcription?
• What is translation?
• What is the genetic code used for?