central dogma

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Page 1: Central dogma

DNA RNA PROTEIN

Transcription Translation

Page 2: Central dogma

Transcription of DNA to RNA to protein: This dogma forms the backbone of molecular biology and is represented by THREE major stages.

1. Replication. 2. Transcription. 3. Translation.

Page 3: Central dogma

Unwinding of DNA to produce a copy during a cell division. The enzymes involved were helicase,polymerase,

RNA primase,ligase.The leading strand operate in a continous fashionWhereas the lagging strand is not in a continous fashion (okazaki fragments)

Page 4: Central dogma

Copying of part of DNA strand (base pair of a gene)

by complementary base pairs.Only one strand of DNA (the template strand) is transcribed.RNA polymerase opens the part of the DNA to be transcribed.

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codon=3 base pairs= responsible for amino acidbuilding blocks of amino acid=protein

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• The ribosome binds to the mRNA at the start codon (AUG)

o During this stage, complexes, composed of an amino acid linked to tRNA, sequentially bind to the appropriate codon in mRNA by forming complementary base pairs with the tRNA anticodon.

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o 2 subunits (large and small) form a 3D groove

o 2 major sites:

P site---holds the growing polypeptide

A site---new amino acids enter here

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The ribosome moves from codon to codon along the mRNA. Amino acids are added one by one, translated into polypeptidic sequences dictated by DNA and represented by mRNA. At the end, a release factor binds to the stop codon, terminating translation and releasing the complete polypeptide from the ribosome.

Page 10: Central dogma