DNA

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• DNA
• (Deoxyribonucleic Acid)

• RNA
• (Ribonucleic Acid)

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Both DNA and RNA

• Are Nucleic Acids
• Macromolecules essential for Life
• Have backbones of made of a sugar and phosphate
  group

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• Both have contain four nitrogenous bases attached
  to the backbone
• Only certain bases are a part of DNA and RNA
• The phosphate group, sugar and nitrogen bases
  make a nucleotide.

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Nucleotide

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What makes DNA and RNA different from each other?

• Structure (Single or Double stranded)
• The sugar (Deoxyribose or Ribose)
• Nitrogenous Bases on the Nucleiotide (ACTG or
  ACUG)
• Function in the organisms (Holding information to
  code for specific protein that determines an
  organisms traits, OR to copy instructions on how
  the protein should be assembled)

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DNA vs. RNA

• DNA
• Double Helix (double stranded
• Looks like a twisted ladder

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• DNA
• Sugar is Deoxyribose
• This gives DNA its name of Deoxyribonucleic Acid.

A
T
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• DNA
• Nitrogen bases are
• Adenine (A)
• Thymine (T)
• Cytosine (C)
• Guanine (G)
• A always pairs with T
• G always pairs with C

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BASE-PAIRINGS

Very weak bonds
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• DNA
• The function of DNA is to hold the information
  that codes for certain proteins which determine
  an organisms traits.
• It is the master copy of information for the
  organism. When the cell is replicated it has to
  make copies of its DNA before it can divide.
• This process is called DNA replication.

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DNA Replication

• DNA must be copied before a cell can divide.
• This is called DNA Replication.
• The DNA molecule produces 2 IDENTICAL new
  complementary strands following the rules of base
  pairing
• A-T, G-C

• Each strand of the original DNA serves as a
  template for the new strand

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DNA Replication

• Watson and Crick showed the two strands of the
  parental molecule separate, and each functions as
  a template for synthesis of a new complementary
  strand.
• .

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• A---?
• G---?
• C---?
• T---?
• A---?
• G---?
• A---?
• G---?
• C---?
• A---?
• G---?
• T---?

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• A---T
• G---C
• C---G
• T---A
• A---T
• G---C
• A---T
• G---C
• C---G
• A---T
• G---C
• T---A

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DNA vs. RNA

• RNA
• Single stranded
• Looks like one-half of a zipper

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• RNA
• Ribose sugar
• This is where RNA gets its name of Ribonucleic
  Acid.

Ribose
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• RNA
• Nitrogen bases are
• Adenine (A)
• Uracil (U)
• Cytosine (C)
• Guanine (G)
• A always pairs with U
• G always pairs with C

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• Remember that DNA holds the instructions for
  making proteins that code for certain traits of
  an organism.
• RNA copies the instructions, carries it to the
  appropriate part of the cell and translates it
  into the amino acids that code for proteins.
• RNA takes the info from DNA to make proteins

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Car Analogy From DNA to Proteins

• One type of RNA, messenger RNA, copies the
  information from DNA in the nucleus, and brings
  these instructions to the cells factory floor,
  the cytoplasm.
• This process is called Transcription.
• 2. On the factory floor, mRNA moves to the
  assembly line, a ribosome.

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• 3. The ribosome, made of Ribosomal RNA, binds to
  the mRNA and uses the instructions to assemble
  the amino acids in the correct order.
• 4. The third type of RNA, transfer RNA is the
  supplier. tRNA delivers amino acids to the
  ribosome to be assembled into a protein.
• This is called Translation.

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• Three nitrogen bases on mRNA a codon
• Three nitrogen bases on tRNA an anticodon
• Codon and Anticodons code for amino acids that
  make proteins.

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Genetic Diversity

• Different arrangements of NUCLEOTIDES in a
  nucleic acid (DNA) provides the key to DIVERSITY
  among living organisms.

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Genetic Changes

• DNA controls the structure and function of the
  cell.
• So what happens when the sequence of DNA
  nucleotides in a gene is changed?
• A substituted base in the DNA molecule changes
  the structure of a protein
• Sometimes it may have little or no harmful
  effect.
• Other times, however, the change can cause the
  cell to behave differently causing cancers or
  other harmful effects.

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Causes of Mutations

• Errors in replication
• Errors in transcription
• Errors in cellular division
• Or by external agents (environmental factors)
• Too much exposure to radiation
• Pollutants
• Nutritional deficiencies

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Gene Mutations

• Point Mutations changes in a single base part
  of nucleotides
• Substitution
• THE FAT CAT ATE THE RAT
• THE FAT HAT ATE THE RAT

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Gene Mutations

• Frameshift mutations- are mutations in which a
  single base is added to or deleted from DNA.

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Gene Mutations

• Frameshift Mutations shifts the reading frame
  of the genetic message so that the protein may
  not be able to perform its function.
• Insertion
• THE FAT CAT ATE THE RAT
• THE FAT HCA TAT ETH ERA T
• Deletion
• THE FAT CAT ATE THE RAT
• TEF ATC ATA TET GER AT

H
H
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Repairing DNA

• Much like a book editor, enzymes proofread the
  DNA and replace incorrect nucleotides with
  correct nucleotides.
• These work well, but they are not perfect.

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Mutations in Reproductive Cells

• If a mutation occurs in a reproductive cell of an
  organism and this cell takes place in
  fertilization, the altered gene would be passed
  on to the offspring.
• Usually this is harmful to the offspring, BUT
  occasionally the gene mutation has a positive
  effect making them more likely to survive.
• This can contribute to the evolution of the
  species.

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Mutations in the Body Cells

• If a mutation occurs in a nonreproductive cell of
  the body such as in the skin, muscle or bone, the
  mutation would not be passed on to the offspring.
  
• The damage of the gene may impair the function of
  the cell.
• If the mutation affects the cells ability to
  control cellular division, the cell may begin to
  divide uncontrollably resulting in cancerous
  tumors.