Cell Membranes and Membrane Transport: Ion Channels and Aquaporins

Play an AI-generated podcast conversation about this lesson

What is the primary difference between simple diffusion and carrier-mediated transport in terms of kinetics?

The rate of uptake of carrier-mediated transport is dependent on the external concentration of the substrate, whereas simple diffusion is not. (correct)

Carrier-mediated transport is limited by the concentration of the substrate, whereas simple diffusion is not.

Simple diffusion is always faster than carrier-mediated transport.

Simple diffusion is a more selective process than carrier-mediated transport.

What is the function of a selective carrier protein in facilitated diffusion?

To decrease the rate of uptake of the solute.

To increase the concentration gradient of the solute.

To inhibit the transport of the solute.

To undergo a conformational change to allow the passage of the solute. (correct)

What is the term for the transport of one solute coupled with the transport of another solute in the same direction?

Symport. (correct)

Facilitated diffusion.

Uniport.

Antipport.

What is the relationship between the Km of a transporter and its affinity for the substrate?

The lower the Km, the higher the affinity. Signup and view all the answers

What is the term for the transport of a solute out of the cell coupled with the transport of another solute into the cell?

Antipport. Signup and view all the answers

What is the name of the family of transporters that mediate facilitated glucose transport?

GLUT1-12. Signup and view all the answers

What is the primary source of energy for primary active transport?

Hydrolysis of ATP Signup and view all the answers

What is the net result of the Na+/K+-ATPase pump in the plasma membrane?

Establishing a high concentration of Na+ outside the cell and a high concentration of K+ inside the cell Signup and view all the answers

What is the role of insulin in regulating GLUT4?

Insulin promotes the translocation of GLUT4 to the plasma membrane Signup and view all the answers

Which type of transport does not require energy?

Passive transport Signup and view all the answers

What is the result of the phosphorylation of the Na+/K+-ATPase pump?

A conformational change that releases Na+ to the exterior Signup and view all the answers

What is the function of the Ca2+-ATPase pump in the endoplasmic/sarcoplasmic reticulum?

To regulate the concentration of Ca2+ in the endoplasmic/sarcoplasmic reticulum Signup and view all the answers

What is the primary mechanism by which solutes move from one side of the membrane to the other along their concentration gradient?

Facilitated diffusion Signup and view all the answers

Which type of transport involves the movement of solutes against their concentration gradient, requiring energy expenditure?

Active transport Signup and view all the answers

What is the role of the octanol-water partition coefficient (Kow) in membrane transport?

It determines the lipid solubility of a molecule Signup and view all the answers

Which type of transporter is responsible for the transmembrane movement of ions and hydrophilic molecules?

Proteins Signup and view all the answers

What is the characteristic of a symporter?

It moves ions and molecules in the same direction Signup and view all the answers

Which statement is true about the Na+/K+ ATPase transporter?

It uses ATP hydrolysis to pump Na+ and K+ Signup and view all the answers