plasma membrane
Cell's outer barrier
The plasma membrane is the thin, flexible boundary that encloses a cell and separates its interior from the outside environment.
Also called the cell membrane, it controls what enters and exits the cell, allowing nutrients in while keeping harmful substances out.
The membrane consists of a double layer of lipids studded with proteins that facilitate transport and communication.
The plasma membrane maintains the cell's internal chemistry by regulating the passage of ions.
Lipids with phosphate groups
- cholesterolWaxy lipid in blood
- fluid mosaic modelCell membrane structural theory
- glycoproteinsSugar-bound cellular proteins
- glycolipidsSugar-bound membrane fats
hydrophobic · hydrophilic · fatty acids · cytoskeleton · anchoring · fluidity · leaflet · rafts
Allowing partial passage
- diffusionPassive molecular spreading
- osmosisSolvent crossing semipermeable barrier
- endocytosisCell engulfs external material
- exocytosisVesicular release from cells
channels · transporters · pumps · carrier proteins · aquaporins · concentration gradient · vesicles · phagocytosis
Proteins binding specific molecules
- phosphorylationPhosphate group attachment process
- neurotransmittersChemical neural messengers
- hormonesBloodstream signaling molecules
- feedbackReturned response data
activation · inhibition · agonist · antagonist · effector
Maintaining internal solute balance
- equilibriumState of balance
- tonicityOsmotic pressure difference
- hypertonicHigher solute than reference
- hypotonicLower osmotic pressure
phospholipids
Lipids with phosphate groups
- cholesterolWaxy lipid in blood
- fluid mosaic modelCell membrane structural theory
- glycoproteinsSugar-bound cellular proteins
glycolipids · hydrophobic · hydrophilic · fatty acids · cytoskeleton · anchoring · fluidity · leaflet · rafts
semipermeable
Allowing partial passage
- diffusionPassive molecular spreading
- osmosisSolvent crossing semipermeable barrier
- endocytosisCell engulfs external material
exocytosis · channels · transporters · pumps · carrier proteins · aquaporins · concentration gradient · vesicles · phagocytosis
receptors
Proteins binding specific molecules
- phosphorylationPhosphate group attachment process
- neurotransmittersChemical neural messengers
- hormonesBloodstream signaling molecules
feedback · activation · inhibition · agonist · antagonist · effector
osmoregulation
Maintaining internal solute balance
- equilibriumState of balance
- tonicityOsmotic pressure difference
- hypertonicHigher solute than reference
- cellscells, blood cell, cell theory, nerve cell, red blood cell
- cell biologycell division, cytoplasm, ribosome, mitochondria, nucleus
- cytologycytology, Pap test, cell division, cytoplasm, chromosome
- body layersepidermis, dermis, epithelium, mucosa, fascia
- cell membranesbilayer, phospholipid, phospholipids, cholesterol, permeability
- Cell Structurescell wall, cytoplasm, ribosome, ribosomes, nucleoid
plasma membranenuclear membrane
Barrier enclosing chromosomes
membrane, plasma, ectoplasm, membranous, plasmas, cell membrane