Unit 2: Cell Transportation Flashcards
Diffusion
Passive movement of substances from high to low concentration areas.
Passive Transport
naturally occurring material transfer from high to low concentration, that does not require energy
Concentration Gradient
Physical space with varying concentrations of a substance.
Facilitated Diffusion
Passive transport aided by membrane proteins for polar molecules. Moves with concentration gradient.
Non-polar and lipid-soluble substances with a low molecular weight can ___ the membrane’s hydrophobic lipid core.
easily slip through
Each separate substance in a medium has its own___, independent of other materials’ ___
concentration gradient
What manner do molecules move in?
constant and random
Factors of molecule movement (3)
their mass, environment, thermal energy (function of temperature)
Channel Proteins
Proteins with hydrophilic channels aiding polar compound passage.
Aquaporins
Channel proteins facilitating high-speed water passage through membranes.
Carrier Proteins
Proteins binding substances, changing shape to transport them across membranes.
Dynamic Equilibrium
State where substance diffusion maintains equal concentration throughout a space.
Factors Affecting Diffusion (8)
Extent of concentration gradient, molecule mass, temperature, solvent density, solubility, surface area, membrane thickness, and distance.
Excretion
Process of removing waste material from the body
Osmosis
Diffusion of water through a semipermeable membrane
Solute
Substance dissolved in a solution
Solvent
Liquid in which a solute is dissolved
Tonicity
Effect of extracellular solution on cell volume through osmosis
Hypotonic
Solution with lower osmolarity than cell cytoplasm
Hypertonic
Solution with higher osmolarity than cell cytoplasm
Isotonic
Solution with same osmolarity as cell cytoplasm
Osmolarity
Total solute concentration in a solution
Turgor Pressure
Pressure of water pushing the plasma membrane against the cell wall
Osmoregulation
Mechanism to control osmotic pressure in living organisms
Adenosine Triphosphate (ATP)
Cellular energy currency used in active transport
Active Transport
Movement of substances against their concentration gradient requiring energy
Metabolic Energy
Energy used to maintain cell processes
Primary Active Transport
Moves substances against gradients using ATP
Secondary Active Transport
Uses ion diffusion energy to transport substances
Uniporter
A transporter that carries one specific solute
Symporter
Carries two different molecules in the same direction
Antiporter
Carries two different molecules in opposite directions
Bulk Transport
Moves large molecules using vesicles and energy
There are two types of bulk transport,
exocytosis and endocytosis
Endocytosis
Brings particles into the cell via vesicle formation
Exocytosis
Expels material from the cell into extracellular space
Phagocytosis
Cell engulfs large particles or cells
Pinocytosis
Cell “drinking” takes in molecules and fluid
Receptor-mediated Endocytosis
Uses specific receptors to bring substances into the cell
Processes that involve movement down a concentration gradient
Osmosis, simple and facilitated diffusion
