Week 2

What is active transport?

The process of moving molecules across a membrane from low to high concentration.

What type of transport proteins are used in active transport?

Special transport proteins in the membrane, including carrier proteins and channel proteins.

What is the role of ATP in active transport?

ATP provides the energy required to move substances against their concentration gradient.

What ions are involved in the sodium-potassium pump?

Sodium (Na+) is pumped into the cell and potassium (K+) is pumped out.

How many sodium ions are exchanged for potassium ions in the sodium-potassium pump?

For every three sodium ions that enter the cell, two potassium ions are ejected.

What are the two main methods of active transport?

Protein pumps and endocytosis/exocytosis.

What is pinocytosis?

A type of endocytosis where cells take in liquid or macromolecules.

What is phagocytosis?

A process where cells engulf large particles or cells, often associated with macrophages.

What happens to a red blood cell placed in a hypertonic solution?

The cell shrivels as water leaves the cell to balance the high concentration of solute in the surrounding solution.

What distinguishes active transport from facilitated diffusion?

Active transport moves molecules against the concentration gradient and requires ATP, while facilitated diffusion moves molecules with the concentration gradient without ATP.

How does the structure of the sodium-potassium pump facilitate active transport?

It has selective binding sites that only allow specific ions to bind, requiring ATP to move them against their concentration gradient.