Active and Passive Transport Basics

Role of concentration gradient

• active transport

• facilitated diffusion

• passive transport

• endocytosis

Passive transport

• molecules without energy

• molecules requiring energy

• molecules actively transported

• molecules with energy

Example of passive transport

• Entering a cell - no energy

• Active transport requiring ATP

• Endocytosis with energy

• Facilitated diffusion with energy

Diffusion

• from low to high concentration

• from high to low concentration

• through a semi-permeable membrane

• in a vacuum

ATP in transport

• energy source for active transport

• passive transport mechanism

• structural component of cell membranes

• waste product of cellular respiration

Active transport

• molecules using energy

• molecules moving passively

• molecules without energy

• molecules in equilibrium

Reason for facilitated diffusion

• To allow uncharged molecules to pass freely

• To enable charged molecules to cross the membrane

• To prevent all molecules from entering the cell

• To increase the speed of diffusion for all substances

Facilitated diffusion

• transport using transport proteins

• active transport against a gradient

• simple diffusion through a membrane

• endocytosis of large molecules

Osmosis

• of water across a membrane

• of nutrients through the bloodstream

• of gases in the lungs

• of ions in a solution

Comparing active and passive transport

• Active transport uses energy, while passive transport does not.

• Both active and passive transport require energy.

• Passive transport uses energy, while active transport does not.

• Active transport and passive transport are the same.