Ion Transport: Basic principles of ion transport

ION CHANNELS

• Subunits
• Different proteins
• Multiple copies of same protein
• Ion-conducting pore
• Electrical and chemical gradients

ION CARRIERS

• Binding
• Conformational changes
• Moves ion
• Energy driven
• Active transport
• Hydrolysis of ATP
• Secondary active transport
• Gradient generated by other transporter
• Carries
• One ion
• Two or more ions, same direction
• Two or more ions, opposite directions
• Charged neutral

TYPES OF IONS MOVED BY TRANSPORT PROTEINS

• Simple actions
• Anions
• Larger ionised molecules