Section 2 Bioelectrical phenomena of the cell
2 Section 2 Bioelectrical Phenomena of the Cell
Basic concepts Volt >A charge difference between two points space
3 Basic Concepts ➢Volt ➢A charge difference between two points in space
Basic Concepts Pons- charged particles Anions-Negatively charged particles > Cations- Positively charged particles
4 Basic Concepts ➢Ions – charged particles ➢Anions – Negatively charged particles ➢Cations – Positively charged particles
Basic Concepts Forces that determine ionic movement Electrostatic forces >Opposite charges attract >Identical charges repel >Concentration forces > Diffusion-movement of ions through semipermeable membrane >Osmosis- movement of water from region of high concentration to low
5 Basic Concepts Forces that determine ionic movement ➢Electrostatic forces ➢Opposite charges attract ➢Identical charges repel ➢Concentration forces ➢Diffusion – movement of ions through semipermeable membrane ➢Osmosis – movement of water from region of high concentration to low
Selective Permeability of Membranes Some ions permitted to cross more easily than others Neuronal membranes contain ion channels >Protein tubes that span the membrane Some stay open all the time (nongated) Some open on the occasion of an action potential causing a change in the permeability of the membrane(gated)
6 Selective Permeability of Membranes ➢Some ions permitted to cross more easily than others ➢Neuronal membranes contain ion channels ➢Protein tubes that span the membrane ➢Some stay open all the time (nongated) ➢Some open on the occasion of an action potential, causing a change in the permeability of the membrane (gated)