Plasma Membrane Flashcards
Phospholipid
Made up of glycerol molecule, two fatty acid chains and phosphate group
Hydrophilic
Attracted to water (head)
Hydrophobic
Not attracted to water (tail)
Cholesterol
Keeps membrane stable when temperature changes
Integral proteins
Transports substances across the membrane
Channel proteins
Narrow hydrophilic pores, substances diffuse through rapidly
Carrier proteins
Change shape as they assist transport of a substance, shape restored after transport
Facilitated diffusion
When diffusion of ions, water soluble or large molecules is aided by specific transport protein
Passive
Not requiring energy
Active
Requiring energy
Diffusion
Passive movement of a molecule from a region of high concentration to low concentration
Concentration gradient
Difference in concentration between two regions
Simple diffusion
Occurs through phospholipids of the membrane bilayer
Equilibirum
When net concentrations of a molecule on each side of the membrane is equal
Osmosis
Passive net movement of water across a differentially permeable membrane from a region of lower solute concentration to one of higher solute concentration
Aquaporins
Membrane proteins that transports water
Isotonic
When extracellular fluid has the same concentration of solutes as intracellular fluid, no net movement
Hypotonic
When extracellular environment has a lower solute concentration than the cell, water enters cell
Hypertonic
When extracellular environment has a higher solute concentration than the cell, water leaves the cell
Flaccid
When a plant cell is in a hypertonic solution, it becomes flaccid
Turgid
When a plant cell is in a hypotonic solution, it becomes turgid
Plasmolysis
When plasma membrane shrinks away from cell wall once too much water has been lost
Active tranport
Required when substances move against their concentration gradient, requires ATP
Pumps
Transport proteins that perform active transport
