Biology Midterm Review

Front

What is active transport?

Back

Active transport is the movement of molecules across a cell membrane from a region of lower concentration to a region of higher concentration, requiring energy (ATP).

Front

What is osmosis?

Back

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

Front

What is facilitated diffusion?

Back

Facilitated diffusion is a process by which molecules pass through the cell membrane via special proteins, moving from an area of higher concentration to an area of lower concentration without the use of energy.

Front

What distinguishes prokaryotic cells from eukaryotic cells?

Back

Prokaryotic cells lack a nucleus and membrane-bound organelles, while eukaryotic cells have a nucleus and organelles.

Front

What role do enzymes play in biochemical reactions?

Back

Enzymes are biological catalysts that speed up chemical reactions by lowering the activation energy required for the reaction to occur.

Front

What is the function of the cell membrane?

Back

The cell membrane regulates what enters and exits the cell, providing protection and support.

Front

Define diffusion.

Back

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

Front

What is the difference between passive and active transport?

Back

Passive transport does not require energy and moves substances down their concentration gradient, while active transport requires energy to move substances against their concentration gradient.

Front

What is a selectively permeable membrane?

Back

A selectively permeable membrane allows certain molecules to pass through while blocking others, maintaining the internal environment of the cell.

Front

What is the significance of the concentration gradient?

Back

The concentration gradient is the difference in concentration of a substance between two areas, driving the movement of molecules during diffusion and osmosis.