RNA

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RNA
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Learning Objectives

• Contrast RNA and DNA.
• Explain the process of transcription.

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Comparing RNA and DNA

• The sugar in RNA is ribose instead of
  deoxyribose.
• RNA is generally single stranded, not double
  stranded.
• RNA contains uracil in place of thymine.

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The Role of RNA

• The roles played by DNA and RNA molecules in
  directing protein production are like the two
  types of plans builders use
• A master plan
• A blueprint

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Types of RNA

• The three main types of RNA are

Transfer RNA
Ribosomal RNA
Messenger RNA
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Messenger RNA

• An mRNA molecule is a copy of the portion of DNA
  that will be used to make a protein.
• After being made in the nucleus, mRNA travels to
  the cytoplasm, the site of protein synthesis.

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Ribosomal RNA

• Protein synthesis occurs on ribosomes, which are
  made up of two subunits.
• Both subunits consist of several molecules of
  ribosomal RNA (rRNA).

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Transfer RNA

• During protein synthesis, transfer RNA molecules
  (tRNA) carry amino acids from the cytoplasm to
  the mRNA.

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RNA Synthesis Transcription

• In transcription, segments of DNA serve as
  templates to produce complementary mRNA molecules.

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RNA Synthesis Promoters

• RNA polymerase binds only to regions of DNA that
  have specific base sequences. These regions are
  called promoters.

G
C
T
A
A
U
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RNA Synthesis RNA Editing

• New RNA molecules sometimes require a bit of
  editing before they are ready to be read.

Exons
Introns
Cap
Tail
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Student Worksheet Answers