Ch. 5 - Membrane DynamicsWorksheetSee all chapters
All Chapters
Ch. 1 - Introduction to Physiology
Ch. 2 - Molecules and Molecular Interactions
Ch. 3 - Cells and Tissues
Ch. 4 - Cell Metabolism: Bioenergetics, Enzymes, and Respiration
Ch. 5 - Membrane Dynamics
Ch. 6 - Cell Communication
Ch. 7 - Integumentary System
Ch. 8 - Bone and Cartilage
Ch. 9 - Skeletal System
Ch. 10 - Joints
Ch. 11 - Muscles
Ch. 12 - The Nervous System I: Neurons and Neuronal Networks
Ch. 13 - The Nervous System II: The Central Nervous System
Ch. 14 - The Autonomic Nervous System
Ch. 15 - Sensory Physiology
Ch. 16 - The Endocrine System
Ch. 17 - Cardiovascular Physiology I: The Heart
Ch. 18 - Cardiovascular Physiology II: Blood, Blood Vessels, Circulation, and Exchange
Ch. 19 - The Urinary System
Ch. 20 - Respiratory Physiology
Ch. 21 - Acid-Base Balance-- Controlling Blood pH
Ch. 22 - Introduction to the Immune System
Ch. 23 The Lymphatic System
Ch. 23 - The Digestive System
Ch. 24 - Regulation of Metabolism and Energy Balance
Ch. 25 - Human Sexual Reproduction and Development

Concept #1: Concentration Gradients and Voltages as Forces

Concept #3: Dual Nature of Ions-- Ions As Chemicals and Charges

Practice: Normally, Na+ ions can’t cross cell membranes very easily, because they’re hydrophilic cations and the membrane is lipophilic. If a Na+ channel in the membrane opens and increases the permeability of the membrane to Na+, which variable in Ohm’s Law (I=Vg) is directly changed by the opening of the channel?

Practice: Normally, Na+ ions can’t cross cell membranes very easily, because they’re hydrophilic cations and the membrane is lipophilic. If a Na+ channel in the membrane opens and increases the permeability of the membrane to Na+, how will that change affect the transmembrane current of Na+?

Practice: A cell is sitting in a KCl solution. Outside the cell, [K+]=10 mM. Inside of the cell, [K+]=100 mM. As a result of this separation of K+, there is a transmembrane voltage V= -61 mV (i.e. the inside of the cell is more negative than the outside). Which of the following accurately describes the type(s) and direction of force(s) acting on the K+ inside of the cell? (Choose all that apply.)