Transcription

BIOCHEMISTRY 3(2+1)
Lesson 28 : DNA and RNA Structures and Protein Synthesis

Transcription

Transcription is the copying of the DNA molecule by mRNA

The 3 steps in Transcription: unzipping, Complementary base pairing and Joining of adjacent nucleotides

  1. Unzipping

    2. A segment of DNA unzips. An enzyme (helicase) breaks the hydrogen bonds between the nitrogenous bases.

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  2. Complementary Base Pairing

    3. RNA nucleotides bind with DNA nucleotides by complementary base pairing on one of the two DNA strands that are exposed after unzipping.

  3. Joining of Adjacent Nucleotides

    4. An enzyme catalyzes the reaction that joins the sugar/phosphate molecules of adjacent nucleotides together.

    The newly produced mRNA strand passes from the nucleus into the cytoplasm to join with a ribosome.

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Last modified: Tuesday, 24 January 2012, 9:07 AM