AP Biology - Unit 2: Active Transport

These flashcards cover key concepts and terms related to active transport and bulk transport mechanisms in biology, providing a useful review for students preparing for exams.

What is active transport?

The movement of substances against their concentration gradient, requiring energy input.

What is the main function of the sodium-potassium pump?

To transport 3 Na+ ions out of the cell and 2 K+ ions into the cell, maintaining an electrochemical gradient.

How does the sodium-potassium pump create a negative membrane potential?

By pumping out more positive ions (3 Na+) than it pumps in (2 K+), resulting in fewer positive charges inside the cell.

Define cotransport.

A membrane protein that actively transports a solute against its concentration gradient by utilizing the concentration gradient of another solute.

What are the two types of bulk transport?

Exocytosis and endocytosis.

Explain the process of exocytosis.

An intracellular vesicle fuses with the plasma membrane to secrete its contents out of the cell.

What occurs during endocytosis?

Cells take in substances by forming vesicles around the material.

What is receptor-mediated endocytosis?

A specific type of endocytosis where certain molecules bind to receptor proteins in the membrane, triggering vesicle formation.

What are the three types of endocytosis?

Phagocytosis, pinocytosis, and receptor-mediated endocytosis.

Explain the difference between active transport and passive transport.

Active transport requires energy to move substances against their concentration gradient, while passive transport occurs along the gradient without energy.