The membrane potential moves toward the equilibrium potential for Na+ (+60 - +65mV) but does not reach it during the action potential, because the increase in Na+ conductance is short-lived.

TLS Online TPP Program

#Id: 2950

#Unit 3. Fundamental Processes

An ARS element consists of an A-T-rich region that contains discrete sites in which mutations affect origin function.

TLS Online TPP Program

#Id: 2951

#Unit 3. Fundamental Processes

An ARS extends for -so bp and includes a consensus sequence (A} and additional elements (B1-B3).

TLS Online TPP Program

#Id: 2952

#Unit 3. Fundamental Processes

Mutations in three adjacent elements, numbered B 1 to B3, reduce origin function.

TLS Online TPP Program

#Id: 2953

#Unit 3. Fundamental Processes

By counting the number of sites to which ORC binds, we can estimate that there are about 400 origins of replication in the yeast genome.

TLS Online TPP Program

#Id: 2954

#Unit 3. Fundamental Processes

By counting the number of sites to which ORC binds, we can estimate that there are about 400 origins of replication in the yeast genome. This means that the average length of a replicon is -35,000 bp.

TLS Online TPP Program

#Id: 2955

#Unit 3. Fundamental Processes

ORC was first found in S. cerevisiae (where it may be called scORC),but similar complexes have now been characterized in Schizosaccharomyces pombe (spORC), Drosophila (DmORC ), and Xenopus (XIORC).