Membrane transport Flashcards
What two properties determine whether a particle can pass across the membrane without assistance?
The solubility and size of the particle.
What is required for all transport?
A pathway and driving force.
How does magnitude of the concentration gradient affect diffusion rate?
Increased magnitude increases diffusion rate.
How does membrane surface area affect diffusion rate?
Increasing membrane surface area increases diffusion rate.
How does lipid solubility affect diffusion rate?
Increasing lipid solubility increases diffusion rate.
How does molecular weight affect diffusion rate?
Increasing molecular weight decreases diffusion rate.
How does distance of diffusion affect diffusion rate?
Increasing diffusion distance decreases diffusion rate.
What is osmolarity?
The concentration of osmotically active particles in solution.
What is tonicity?
The effect a solution has on the volume of a cell.
What is passive transport dependent on?
Lipid solubility
What are the two types of selective transport?
Carrier-mediated and vesicular.
What are the two forms of carrier mediated transport?
Facilitated diffusion and active transport.
What is primary active transport?
Active transport in which energy is directly needed to move substances against their gradient.
What is secondary active transport?
Active transport in which energy is not directly required to move substances against their concentration gradient but instead the substance is moved by energy from an ion concentration gradient.
What is a symporter?
A type of secondary active transport where the substance is moved in the same direction as the driving ion.
