Movement of molecules in and out of cells: Dissolved Substances

Dissolved Substances

Diffusion:

• Diffusion is the movement of particles from a region of high concentration to an area of low concentration, which is down a concentration gradient.
• Only gases and liquids can diffuse.
• Oxygen and carbon dioxide diffuses between the lungs and the blood.
• Carbon dioxide diffuses into the air spaces in a leaf.
• Nutrients from digested food diffuse from the gut cavity in the small intestine into the blood capillaries in the villi.

What does Diffusion mean?

Diffusion is the movement of particles (molecules or ions) from an area of higher concentration to an area of lower concentration.

Active Transport:

• Active transport is the net movement of particles from an area of low concentration to high concentration using energy.
• Active transport is against a concentration gradient.
• Protein carriers in membranes absorb molecules in active transport.
• Root hair cells in plant roots absorb mineral ions by active transport.
• Active transport in the small intestine absorbs glucose into the blood.

What does Active Transport mean?

Active Transport is the transport of molecules against their concentration gradient from a region of low concentration to a region of high concentration.

What does Cell Membrane mean?

The Cell Membrane is a selectively permeable membrane surrounding…