Cell Membrane & Transport

Front

What is the primary function of the plasma membrane in cells?

Back

The plasma membrane serves as a barrier that regulates the movement of substances in and out of the cell, maintaining homeostasis.

Front

Define active transport in the context of cell membranes.

Back

Active transport is the movement of substances across a cell membrane against their concentration gradient, requiring energy (ATP) to do so.

Front

What is passive transport and how does it differ from active transport?

Back

Passive transport is the movement of substances across a cell membrane without the need for energy input, occurring along the concentration gradient.

Front

What is facilitated diffusion?

Back

Facilitated diffusion is the process of moving particles across a cell membrane with the help of transport proteins, following the concentration gradient.

Front

Explain the process of exocytosis.

Back

Exocytosis is the process by which cells expel large particles or substances by vesicles fusing with the plasma membrane, releasing their contents outside the cell.

Front

What role do transport proteins play in cellular transport?

Back

Transport proteins assist in the movement of substances across the plasma membrane, either by facilitating diffusion or by actively transporting molecules.

Front

What is the concentration gradient?

Back

The concentration gradient is the difference in the concentration of a substance across a space, which drives the movement of particles from areas of high concentration to areas of low concentration.

Front

Describe the difference between endocytosis and exocytosis.

Back

Endocytosis is the process of taking substances into the cell by engulfing them in a vesicle, while exocytosis is the process of expelling substances from the cell.

Front

What is osmosis and how does it relate to cell membranes?

Back

Osmosis is the diffusion of water across a selectively permeable membrane, moving from an area of lower solute concentration to an area of higher solute concentration.

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 or crenate due to loss of water.