Cell Transport

Front

What is facilitated diffusion?

Back

Facilitated diffusion is a process by which molecules move across a cell membrane through protein channels, from an area of high concentration to an area of low concentration, without the use of energy.

Front

What is the role of protein pumps in cell transport?

Back

Protein pumps are membrane proteins that use energy (usually from ATP) to move molecules against their concentration gradient, from low concentration to high concentration.

Front

How does the cell membrane maintain homeostasis?

Back

The cell membrane maintains homeostasis by controlling the movement of substances in and out of the cell, ensuring that essential nutrients enter and waste products exit.

Front

What is the structure of a phospholipid?

Back

A phospholipid consists of a hydrophilic (water-attracting) 'head' and two hydrophobic (water-repelling) 'tails', allowing it to form a bilayer in cell membranes.

Front

What is diffusion?

Back

Diffusion is the passive movement of molecules from an area of high concentration to an area of low concentration until equilibrium is reached.

Front

What is the difference between diffusion and facilitated diffusion?

Back

Diffusion occurs directly through the lipid bilayer, while facilitated diffusion requires specific protein channels to help transport molecules.

Front

What is endocytosis?

Back

Endocytosis is the process by which cells engulf substances from the outside environment, forming a vesicle to bring them into the cell.

Front

What is exocytosis?

Back

Exocytosis is the process by which cells expel materials in vesicles that fuse with the cell membrane, releasing their contents outside the cell.

Front

What is a concentration gradient?

Back

A concentration gradient is the difference in the concentration of a substance across a space, which drives the movement of molecules during diffusion.

Front

What types of molecules can pass through the cell membrane easily?

Back

Small, nonpolar molecules (like oxygen and carbon dioxide) can pass through the cell membrane easily, while larger or polar molecules require assistance.