In a microtubule,

The end with exposed β-subunits is the (+) end

The end with exposed α-subunits is the (−) end

 

TLS Online TPP Program

#Id: 2980

#Unit 3. Fundamental Processes

It does not exist as an independent unit (e.g., analogous to the ribosome), but assembles de novo at the origin for each replication cycle.

TLS Online TPP Program

#Id: 2981

#Unit 3. Fundamental Processes

DNA is synthesized in both semiconservative replication and repair reactions.

TLS Online TPP Program

#Id: 2982

#Unit 3. Fundamental Processes

Only one DNA polymerase is the replication enzyme. The others participate in repair of damaged DNA, restarting stalled replication forks, or bypass 1ng damage in DNA.

TLS Online TPP Program

#Id: 2983

#Unit 3. Fundamental Processes

All prokaryotic and eukaryotic DNA polymerases share the same fundamental type of synthetic activity, antiparallel synthesis from 5' to 3' from a template that is 3' to 5'.

TLS Online TPP Program

#Id: 2985

#Unit 3. Fundamental Processes

A comprehensive series of such temperature-sensitive mutants in Escherichia coli identifies a set of loci called the dna genes. The dna mutants distinguish two stages of replication by their behavior when the temperature is raised

The members of the major class of quick-stop mutants cease replication immediately upon a temperature increase.

The members of the smaller class of slow-stop mutants complete the current round of replication, but cannot start another.

TLS Online TPP Program

#Id: 2986

#Unit 3. Fundamental Processes

In E. coli., DNA polymerase III, a multisubunit protein, is the replication polymerase responsible for de novo synthesis of new strands of DNA.