Midterm 1

Fluid Mosaic Model

Describes the cell membrane as a dynamic structure with a phospholipid bilayer embedded with proteins and biomolecules.

Hydrophilloic

Phospholipids have water-attracting heads

Hydrophobic

Phospholipids tails and rebel water

Concentration Gradients

Difference in amount of solute

Permability

ability of molecules to pass through the membrane.

Brownian Motion

random particle movement

Diiffusion

the passive movement of molecules across a membrane.

Osmosis

The diffusion of water across a selectively permeable membrane from low to high solute concentration areas.

Crenation

Cell shrinking due to water loss

Lyse

cell bursting due to water influx

Simple diffusion

Small, non-polar molecules move through the lipid bilayer.

Facilitated diffusion

Larger or polar molecules use proteins for movement.

Active

Requires energy to move molecules against their concentration gradient.

SAT

Uses stored energy to drive molecule movement.

Filtration

Movement of substances across a membrane due to pressure differences.

Phagocytosis

cells engulf large particles (cell eating)

Pinocytosis

fluid droplets by forming vesicles (cell drinking)

Endocytosis

Processes of internalizing large molecules or particles through membrane-bound vesicles.

Exocytosis

Processes of externalizing large molecules or particles through membrane-bound vesicles.

Cotransport

substances are transported across a cell membrane using the energy derived from the movement of another molecule or ion down its electrochemical gradient

Antiport

Coupled molecule move in opposite directions

Symport

Coupled molecule move in same direction