Diffusion, Osmosis and Active Transport

What is diffusion?

Movement of molecules from a high concentration to a low concentration down a concentration gradient. Does not require energy. Transports CO₂, water and O₂.

What are six factors affecting the rate of diffusion?

Temperature, Surface area, size of particles, concentration gradient, diffusion medium and diffusion distance.

How does temperature affect rate of diffusion?

The higher the temperature, the faster the rate of diffusion

How does surface area affect rate of diffusion?

The larger the surface area, the faster the rate of diffusion

How does the size of particles affect the rate of diffusion?

The smaller the particles, the faster the rate of diffusion

How does the concentration gradient affect the rate of diffusion?

The higher the concentration gradient, the faster the rate of diffusion

What is diffusion medium and how does it affect rate of diffusion?

Solid, slowest rate of diffusion. Liquid, faster and gas is the fastest rate of diffusion

How does diffusion distance affect rate of diffusion?

The shorter the distance, the faster the rate of diffusion

How does Oxygen diffuse into the lungs?

From a high concentration in the air to a low concentration in the blood

What is Osmosis?

The movement of water molecules from a high concentration to a low concentration across a semi permeable membrane. It does not require energy

What are the three solutions

Hypotonic, Isotonic and Hypertonic

What is a Hypertonic solution?

A solution with a higher solute and a lower water concentration

What is an Isotonic solution?

Normal

What is a Hypotonic solution?

A solution with low solute and higher water concentration

What happens when substances move in an Animal in a Hypotonic solution?

Water will diffusion from a higher water concentration outside the cell to a lower water concentration inside the cell. It will swell up and burst called Lysed.

What happens when substances move in an Animal in a Hypertonic solution?

Water will diffuse from a higher water concentration to a lower water concentration outside the cell. The cell will lose water and shrink called Shrivelled.

What happens when substances move in an Plant in a Hypotonic solution?

Water will diffuse from a higher water concentration outside the cell to a lower water concentration inside the cell. Gain water by osmosis and swell up until their cytoplasm and cell membrane are pushing against their wall called Turgid.

What happens when substances move in an Plant in a Hypertonic solution?

Water will diffuse from a higher water concentration inside the cell to a lower water concentration outside the cell. Their cell membranes will peel away from their cell wall called Plasmolysis.

What is Active Transport?

Active Transport is used to move substances in and out of cells against a concentration gradient. From low concentration to high concentration. Requires energy and a semi-permeable membrane.