Cell Structure STAAR Review

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 higher concentration to an area of lower concentration, without the use of energy.

Front

What type of cells have membrane-bound organelles?

Back

Eukaryotic cells have membrane-bound organelles, which include structures like the nucleus, mitochondria, and endoplasmic reticulum.

Front

What occurs when there is no concentration gradient across a semipermeable membrane?

Back

The system is in equilibrium, meaning there is no net change in the movement of water or solutes across the membrane.

Front

Why is energy required for active transport?

Back

Energy is required for active transport because ions or molecules are moved against their concentration gradient, from an area of lower concentration to an area of higher concentration.

Front

What is diffusion?

Back

Diffusion is the process by which molecules spread from an area of high concentration to an area of low concentration until they are evenly distributed.

Front

What is osmosis?

Back

Osmosis is the diffusion of water molecules through a selectively permeable membrane from an area of lower solute concentration to an area of higher solute concentration.

Front

What is the difference between prokaryotic and eukaryotic cells?

Back

Prokaryotic cells do not have a nucleus or membrane-bound organelles, while eukaryotic cells do.

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.

Front

What is the role of membrane proteins in facilitated diffusion?

Back

Membrane proteins provide pathways for specific molecules to cross the cell membrane during facilitated diffusion.

Front

What happens to a cell in a hypertonic solution?

Back

In a hypertonic solution, water moves out of the cell, causing it to shrink.