Mechanisms of Transport - AP Biology

Transport of two substances in the same direction across a membrane. Both substances move together in same direction.

The voltage difference across a cell's plasma membrane. Results from unequal ion distribution across membrane.

Exocytosis. Vesicles transport waste to the cell surface.

Exocytosis. Vesicles transport waste to the cell surface.

The difference in concentration of a substance across a space. This drives the direction of passive transport.

The movement of particles from high to low concentration. This process continues until equilibrium is reached.

The process of expelling materials from the cell via vesicles. Vesicles fuse with membrane to release contents.

Cell recognition and communication. Sugar chains on proteins enable cellular identification.

Channel proteins. These form specific pathways for ion movement.

Sodium-potassium pump. Maintains cellular ion gradients essential for nerve function.

To regulate the movement of substances in and out of the cell. This selective permeability controls cellular homeostasis.

Allowing certain substances to pass through while blocking others. Membrane proteins determine this selective passage.

A solution with equal solute concentration to another. Equal concentrations prevent net water movement.

To transport protons across membranes, creating a gradient. Essential for chemiosmosis in cellular respiration.

Polar or charged molecules. These cannot cross the lipid bilayer directly.

Ion transport. Charged particles require specific protein channels.

The process of taking in materials by engulfing them in the cell membrane. The cell membrane invaginates to form vesicles.

Phospholipids. These amphipathic molecules form the bilayer structure.

Movement of substances against their concentration gradient using energy. ATP hydrolysis powers this uphill transport process.

To transport substances across the cell membrane. They undergo conformational changes to move substances.

They assist in cell-cell recognition. Carbohydrate markers enable immune system recognition.

Movement of substances across the membrane without energy input. Driven by concentration gradients and kinetic energy.

Endocytosis. Endocytosis requires ATP for membrane deformation and vesicle formation.

Proton gradient. This electrochemical gradient drives ATP synthesis.

Higher temperature increases diffusion rate. Increased kinetic energy accelerates molecular movement.

To maintain the electrochemical gradient in cells. Essential for nerve impulses and cellular signaling.

The coupled transport of two substances across a membrane. One substance's gradient drives another's transport.

Active transport requires energy, passive does not. Energy requirement distinguishes these transport types.

A solution with a higher solute concentration than another. Higher solute concentration creates osmotic pressure.