AP Bio Diffusion & Osmosis Practice Quiz

Diffusion is a passive process where molecules move from areas of high concentration to low concentration. This movement occurs due to the inherent kinetic energy of the molecules seeking equilibrium.

Osmosis specifically refers to the movement of water molecules through a semipermeable membrane. The water moves from regions with lower solute concentrations to regions with higher solute concentrations to balance the solute levels.

A concentration gradient is the variation in the concentration of a substance between two regions. It provides the driving force for the diffusion process as molecules move to areas of lower concentration.

A semipermeable membrane works by selectively allowing certain molecules, like water, to pass through while restricting others. This selective permeability is crucial for maintaining proper cell function.

Osmosis is the process that helps cells balance solute concentrations by allowing water to move across a semipermeable membrane. It is essential for maintaining cellular equilibrium and overall homeostasis.

The concentration gradient, molecular size, and temperature are all key factors that influence diffusion rates. However, the color of a molecule is unrelated to its physical movement or diffusion efficiency.

Active transport moves molecules against the concentration gradient and needs energy, typically in the form of ATP. In contrast, passive transport relies on natural diffusion without any energy expenditure.

Increasing the temperature boosts the kinetic energy of molecules, making them move faster. This enhanced molecular movement speeds up the process of diffusion.

In a hypotonic solution, the external solute concentration is lower than that inside the cell, causing water to move into the cell. This influx of water can lead to the cell swelling and potentially bursting.

The water potential gradient is the difference in water potential between two regions. This gradient is the driving force behind the movement of water during osmosis.

In a hypertonic solution, the high external solute concentration draws water out of the cell. This loss of water causes the cell to shrink, a process known as crenation.

A larger surface area offers more space for molecules to diffuse across a membrane. This generally increases the overall rate of diffusion because more molecules can pass through simultaneously.

Diffusion is a passive process that occurs due to concentration gradients, enabling molecules to move without the need for energy input. This natural movement is fundamental to many cellular processes.

A semipermeable membrane permits water molecules to pass while blocking larger solute molecules. This selective permeability is key to establishing the osmotic conditions observed in experiments.

Diffusion facilitates gas exchange by permitting oxygen to enter cells and carbon dioxide to leave during cellular respiration. This process is essential for maintaining the metabolic functions of the cell.

Fick's Law states that diffusion is influenced by factors such as surface area, membrane thickness, and the concentration gradient. The color of the cell is unrelated to the physical properties governing the rate of diffusion.

Aquaporins are specialized protein channels that facilitate the rapid movement of water molecules across the cell membrane. They enable efficient osmosis without the expenditure of cellular energy.

Plasmolysis is observed when plant cells lose water in a hypertonic solution, causing the cell membrane to pull away from the cell wall. This phenomenon effectively demonstrates the impact of osmotic pressure differences on cells.

Osmosis does not consume cellular energy because water moves along its concentration gradient without assistance. This natural and energy-independent movement characterizes osmosis as a passive process.

Changes in pH can affect the tertiary structure of proteins such as aquaporins, potentially altering their function. This may indirectly influence the rate and efficiency of osmosis in experimental settings.