What molecule is pictured?

1

• What molecule is
  pictured?
• What are genes?
• Why should I care?

2

• DNA
• Genes are sections of DNA
• that code for heritable
• traits and proteins.
• B/C some traits are
• beneficial, but some are
• harmful (deadly).

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DNA Revolution

• 1860sMendel is considered the father of genetics
• was the first to scientifically prove parents
  pass some of their DNA/genes/traits to their
  offspring.

4

• What does DNA do?
• Carries the code (instructions) for all
  genes/traits/proteins in every cell in every
  living organism.

5

• What does DNA (nucleic acid) do?
• An organisms DNA/genes determine which proteins
  an organism (bacteria, plant, animal, fungi,
  protist) can produce.

6

• What does DNA do?
• Proteins, like enzymes, perform much of the work
  in a cell.

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• How is DNA put together?
• DNA is made up
• of nucleotides
• Each nucleotide is
• made up of a
• 1. sugar
• 2. phosphate group
• 3. nitrogen base

8

• How is DNA put together?
• DNA is a Ladder
• 1. Sugar (deoxyribose)
• and phosphate
• groups are the
• sides of the ladder
• 2. Nitrogen bases
• make up the rungs

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Nucleotide
Hydrogen bonds
Sugar-phosphate backbone
Key Adenine (A) Thymine (T) Cytosine (C) Guanine
(G)
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Eukaryote Chromosomes
DNA double helix
Chromosome
Supercoils
Coils
Nucleosome
Histones
Our cells have about 6 billion base pairsenough
to fill about 900 thick textbooks! Errors in
copying? Only about one per every billion
nucleotides.
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• DNA Nitrogen bases
• Adenine (A)
• Thymine (T)
• Guanine (G)
• Cytosine (C)
• A bonds (pairs) with T / G bonds (pairs) with C

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DNA Replication

• DNA opens or unzips at the hydrogen bonds with
  the help of the enzyme (proteins), helicase, and
  copies in both directions.
• 2. Other enzymes (proteins) add free nucleotides
• (About 50 per second in humans!)

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• DNA Replication
• 3. Base pairs are bonded until entire chain is
  copied.
• IMPORTANT Since the DNA is being copied in
  both directions, 2 copies of DNA are made.

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DNA replicates before Mitosis and Meiosis
Growth
DNA polymerase
Growth
Replication fork
Replication fork
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• What would the complementary DNA strand for
  ATCGGTACATTC be?
• TAGCCATGTAAG
• What would the complementary DNA strand for
  CGTAATGGCTAT be?
• GCATTACCGATA
• What would the complementary DNA strand for
  ATCGTTAGGCTC be?
• TAGCAATCCGAG

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Importance of DNA sequence

• Used to determine evolutionary relationships
• Paternity relationships
• Crime scene matches
• Disease identification and therapy

17

• Structure of RNA (a nucleic acid)
• RNA is a molecule also
• made up of nucleotides
• 1. sugar
• 2. phosphate
• 3. nitrogen base

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Differences between DNA RNA

• 1.The nitrogen base
• Uracil replaces
• Thymine.
• 2. Ribose is the
• sugar.
• 3. RNA is single
• stranded.

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The function (job) of RNAs is ProteinSynthesis

• 2 Steps
• Transcription takes place in the nucleus of the
  cell
• Translation- takes place in the cytoplasm of the
  cell

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• Protein Synthesis
• Step 1. Transcription
• Transcription takes place in the nucleus - mRNA
  gets the code from DNA for a specific protein.

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Step 1. Transcription

• mRNA Messenger RNA - gets code from DNA.

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• Protein Synthesis
• 2. Translation
• Then, mRNA carries
• this code into the
• cytoplasm and meets up with rRNA at the
  ribosome.

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• Step 2. Translation
• rRNA Ribosomal RNA translates the coded
  instruction for the specific protein.

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• Protein Synthesis
• 2. Translation
• Once mRNA and rRNA join up in the cytoplasm, they
  take the code and translate it into instructions
  for making proteins for the cell.

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• Translation Continued
• mRNA uses codons
• a set of 3 nitrogen
• bases- to represent
• different amino acids

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• What do RNAs do?
• 3. tRNA Transfer RNA transport and attaches
  the amino acids to make the specific protein.

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• Step 2. Translation
• Next, tRNAs bring
• the specific amino acids
• to mRNA/rRNA and
• add the A.A.s together
• to make the
• particular protein.

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(No Transcript)
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• What would the complementary mRNA strand for
  ATCGGTACATTC be?
• UAGCCAUGUAAG
• What would the complementary mRNA strand for
  CGTAATGGCTAT be?
• GCAUUACCGAUA
• What would the complementary mRNA strand for
  ATCGTTAGGCTC be?
• UAGCAAUCCGAG

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• http//www.abpischools.org.uk/page/modules/hormone
  s/horm6.cfm
• http//www.lpscience.fatcow.com/jwanamaker/animati
  ons/Protein20Synthesis20-20long.html
• http//www.littletree.com.au/dna.htm