Resting Membrane Potential: This is the baseline membrane potential of a cell at rest, typically around -70 millivolts (mV) in animalcells. It is primarily maintained by the unequal distribution of ions across the cell membrane, with the inside of the cell being more negative compared to the outside.
Ion Pumps:Enzymes that actively transportions across the membrane against their electrochemical gradient, consuming energy (usually ATP) in the process. Examples include the sodium-potassium pump, which helps maintain the resting membrane potential.
Permeability of the Membrane: The ease with which ions can move across the membrane, determined by the presence and activity of specific ion channels.
Electrochemical Equilibrium: The balance between the electrical and chemicalforces acting on ions, which determines their movement across the membrane.
Study Guide:
When studying membrane potential, it's important to focus on the following key areas:
Understand the principles of diffusion and electrochemical gradients, and how they contribute to the establishment of membrane potential.
Learn about the major ions involved in generating membrane potential, their distribution across the membrane, and the role of ion pumps and channels in maintaining this distribution.
Explore the concept of resting membrane potential and its significance in cellphysiology.
Consider the clinical implications of disruptions in membrane potential, such as in neurological disorders or cardiac arrhythmias.
By mastering these concepts and principles, you'll develop a comprehensive understanding of membrane potential and its importance in cellular function and signaling.
Energy - A. Energy is involved in all physical and chemical processes. It is conserved, and can be transformed from one form to another and into work. At the atomic and nuclear levels energy is not continuous but exists in discrete amounts. Energy and mass are related through Einstein's equation E=mc 2 . B. The properties of atomic nuclei are responsible for energy-related phenomena such as radioactivity, fission and fusion. C. Changes in entropy and energy that accompany chemical reactions influence reaction paths. Chemical reactions result in the release or absorption of energy. D. The theory of electromagnetism explains that electricity and magnetism are closely related. Electric charges are the source of electric fields. Moving charges generate magnetic fields. E. Waves are the propagation of a disturbance. They transport energy and momentum but do not transport matter.
Relate temperature to the average molecular kinetic energy.