cell transport

Passive transport

• cellular transport that does not require energy (ATP)

• moves WITH/DOWN the concentration gradient (to balance) 

• EX: simple diffusion, protein channels/transport proteins, facilitated diffusion, osmosis, diffusion

Simple Diffusion

• passive transport

• molecules move directly through the phospholipid bilayer from high to low concentration

• Usually for small and nonpolar molecules

Facilitated diffusion

• passive transport

• when needing to move through a membrane from high to low concentration

• Molecules move directly through transport proteins/protien channels/ion channels 

• usually for bigger and/or polar molecules 

• EX: Aquaporins: form protein channels that allow water to move across the membrane quickly down its concentration gradient 

Transport protien/protien channel

• type of passive transport

• protein that aids in cellular transport and facilitated diffusion

• embedded in the phospholipid bilayer

Active Transport

• cellular transport that requires energy (ATP)

• moves AGAINST the concentration gradient 

• EX: Endocytosis, Exocytosis, molecular transport, bulk transport, primary active transport, secondary active transport

Primary Active Transport

• directly uses ATP

Secondary Active Transport 

• indirectly uses ATP

• Usually utilizes the membrane potential created by primary active transport

molecular active transport

active transport for SMALL amounts of molecules from low to high concentration

EX: sodium potassium pump

bulk active transport

active transport for LARGE amounts of molecules or very large molecules and/or polar molecules across the membrane

Endocytosis (func + types)

• bulk active transport moving INTO the cell 

types: Pinocytosis, Phagocytosis, Receptor-Mediated Endocytosis 

• ALL using Vesicles

Pinocytosis 

engulphing LIQUID enviroment (“Cell drinking”)

Phagocytosis

engulphing LARGE SOLID contents from the enviorment (“Cell eating”)

(x) Receptor Mediated Endocyrosis

engulphing target substances by signaling molecules 

(x) signaling molecules

ligands that have bound to receptors on the outer surface of the cell membrane

exocytosis

bulk active transport moving OUT of the cell

Hypertonic

solute concentration is GREATER OUTSIDE the cell = water rushes out of the cell and the cell shrivels 

EX: very salty water

Hypotonic

Solute concentration is GREATER INSIDE the cell = water rushes in the cell and the cell swells, able to burst 

EX: distilled water

Isotonic

solue concentration is the SAME INSIDE AND OUTSIDE of the cell, water moves both in and out of the cell at the same rate 

EX: Ringer’s solution

Osmosis

• A type of diffusion that goes through a semipermeable membrane

• water molecules moving from a high to low concentration of solute 

• EX: moves through aquaporins

Diffusion

the process of molecules spreading out from an area of high concentration to low concentration w/o a semipermiable membrane