Principal function of all 3 human TGF-β isoforms, TGF-β1, 2, and 3:

Prevent cell proliferation by inducing the synthesis of p15 INK4B

TLS Online TPP Program

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#Unit 3. Fundamental Processes

significantly higher dissociation rate at 25C than at 37C, and a much higher dissociation rate at 15C. Because high temperature promotes DNA melting

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#Unit 3. Fundamental Processes

TLS Online TPP Program

#Id: 6284

#Unit 3. Fundamental Processes

Mechanism: How Polymerase Find Promoter Sequences

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#Id: 6285

#Unit 3. Fundamental Processes

TLS Online TPP Program

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#Unit 3. Fundamental Processes

The overall reaction rate for the bacterial RNA polymerase can be as fast as 40–50 nucleotides/ second at 37°C for most transcripts; this is about the same as the rate of translation (15 amino acids/sec), but much slower than the rate of DNA replication (800 bp/sec).

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#Unit 3. Fundamental Processes

As RNA polymerase moves along the DNA template, it unwinds the duplex at the front of the bubble (the unwinding point), and the DNA  automatically reforms the double helix at the back (the rewinding point).  The length of thetranscription bubble is 12 to 14 bp, but the length of the RNA–DNA hybrid within the bubble is only 8 to 9 bp. As the enzyme moves along the template, the DNA duplex reforms, and the RNA is displaced as a free polynucleotide chain The last 14 ribonucleotides in the growing RNA are complexed with the DNA and/or the enzyme at any given moment.