SA node has an unstable resting membrane potential. The “resting membrane potential” of the sinus nodal fiber between discharges has a negativity of about −55 to −60 millivolts.

#Id: 624

#Unit 2. Cellular Organization

Dual hairpin formation (Region 3-4 forms hairpin then second hairpin is formed between Region 1-2) release RNA-DNA hybrid and RNA Polymerase causes seizing transcription of trp operon at high trp concentration.

#Id: 7149

#Unit 6. System Physiology – Plant

In the local defense response, there are two ways of short-distance transmission of the JA signal. First, the systemin produced by the wounding acts as a signaling molecule, which is transmitted to the adjacent site through the apoplast and phloem to activate the JA cascade reaction pathway. Second, JA and JA-Ile induced by systemin act as signals and are transported to adjacent sites for defensive responses

#Id: 5261

#Unit 7. System Physiology – Animal

#Id: 326

#Unit 1. Molecules and their Interaction Relevant to Biology

When blood glucose rises above 5 mM, hexokinase IV activity increases, but hexokinase I is already operating near Vmax and cannot respond to an increase in glucose concentration. 

#Id: 5350

#Unit 10. Ecological Principles