Biology - cell membrane transport

phospholipids

Molecules that form the basic structure of cell membranes, consisting of a hydrophilic head and two hydrophobic tails, allowing for the formation of a lipid bilayer.

cell membrane

a thin, protective layer that surrounds every cell, separating its internal parts from the outside environment and controlling what goes in and out, acting like a gatekeeper for nutrients, waste, and other substances

diffusion

the natural spreading out of particles (atoms, molecules) from an area where they are crowded (high concentration) to an area where there are fewer of them (low concentration) until they are evenly spread

osmosis

the movement of water from where there's more water (less stuff dissolved) to where there's less water (more stuff dissolved), passing through a special barrier (a semipermeable membrane) to try and balance things out

facilitated diffusion

a type of passive cell transport where molecules move from high to low concentration across a membrane, but need help from transport proteins (like channels or carriers) to cross, without the cell using extra energy (ATP)

active transport

a cell's process of moving substances (like ions or molecules) across its membrane against their concentration gradient (from low to high) or electrochemical gradient, which requires the cell to expend energy, usually in the form of ATP, often using specific protein "pumps"

endocytosis

the process of taking materials into the cell

exocytosis

 the process of taking materials out of the cell

phagocytosis

Phagocytosis is the process  of taking particles into the cell

pinocytosis

the process of taking fluid into the cell

hypertonic

has more solute (less water) than a cell, causing water to leave the cell, making it shrink

hypotonic

has less solute (more water) than a cell, causing water to rush in and cells to swell

isotonic

having the same concentration of solutes (like salt) and water as another solution, usually the inside of a body cell or blood, leading to no net water movement across the cell membrane, keeping cells stable

fluid mosaic

the structure of the cell membrane as a dynamic, flexible sheet composed of a "mosaic" of various components that can move around, like a liquid

tissue

a group of similar cells that work together to perform a specific job in a living organism

organ

a groups of tissues that work together

organ system

a group of organs that work together to perform a specific function