Biology Chapter on Diffusion

The movement of molecules from an area of high concentration to an area of low concentration.

A difference in the concentration of a substance between two areas.

The random movement of molecules, driven by their kinetic energy.

The state where molecules are evenly distributed and there's no net movement.

A membrane that allows some molecules to pass through but blocks others.

The movement of water molecules from an area of high water concentration to an area of low water concentration across a semi-permeable membrane.

A process that requires energy to move molecules against their concentration gradient.

Movement of molecules across a membrane that does not require energy.

The rate of diffusion increases with higher temperatures because molecules have more kinetic energy and move faster.

The rate of diffusion decreases as the distance over which diffusion needs to occur increases.

A greater difference in concentration between two areas leads to a faster rate of diffusion.

The rate of diffusion is higher when the surface area available for diffusion is larger. For example, root hairs in plants increase surface area for water absorption.

A solution with the same concentration of solutes as another solution.

A solution with a higher concentration of solutes than another solution.

The movement of oxygen from the alveoli (air sacs) in the lungs into the blood capillaries and the movement of carbon dioxide from the blood capillaries into the alveoli, both driven by differences in concentration.

Nutrients like carbohydrates, proteins, and fats are broken down into smaller molecules. These molecules are then absorbed from the small intestine into the bloodstream through the process of diffusion.

The exchange of nutrients and waste products between the mother's blood and the fetal blood occurs through the placenta, a specialized organ in the uterus. This exchange involves the movement of substances across the placenta's surface by diffusion.

Carbon dioxide (CO2) produced during photosynthesis is released from the mesophyll cells of leaves into the air spaces within the leaves. This movement occurs by diffusion, driven by the concentration difference between CO2 inside the cells and the air spaces.

A larger surface area allows for more efficient diffusion, as there are more points of contact for movement.

Factors like temperature and the size and nature of the molecules can influence the speed of diffusion.

The cell shriveled up and become small and wrinkled.

The cell swells up and may burst due to excess water intake.

The cell remains in a stable state as there is no net movement of water.

The plant cell becomes firm and rigid due to the pressure from water inside the cell.

The plant cell becomes soft and limp due to water leaving the cell.

The pressure exerted by the cell's contents against the cell wall. It is essential for maintaining the plant's shape and rigidity.

The movement of water across a semi-permeable membrane from a region of high water concentration to a region of low water concentration.

It is a measure of the free energy of water. In simple terms, it indicates the potential of water to move from one area to another.

The process where plant cells lose water and shrink due to a hypertonic environment, leading to wilting.

Special proteins embedded in cell membranes that facilitate the movement of substances across the membrane.

Energy-rich molecule produced by respiration, providing the fuel for active transport.

The process where root hairs absorb essential mineral ions from the soil against the concentration gradient, using active transport.

Specialized cells in the small intestine that absorb glucose and amino acids from the digested food, utilizing active transport.

The process where the kidneys reabsorb vital substances like glucose, amino acids, and ions back into the bloodstream, powered by active transport.