Cell Membrane Flashcards
Exocytosis
a process by which the contents of a cell vacuole are released to the exterior through fusion of the vacuole membrane with the cell membrane.
Phagocytosis
the ingestion of bacteria or other material by phagocytes and amoeboid protozoans.
Contractile Vacuole
a membrane-enveloped cellular organelle, found in many microorganisms, that periodically expands, filling with water, and then contracts, expelling its contents to the cell exterior: thought to be important in maintaining hydrostatic equilibrium.
Osmosis
a process by which molecules of a solvent tend to pass through a semipermeable membrane from a less concentrated solution into a more concentrated one, thus equalizing the concentrations on each side of the membrane.
Plasmolysis
contraction of the protoplast of a plant cell as a result of loss of water from the cell.
Vesicle
In cell biology, a vesicle is a small structure within a cell, consisting of fluid enclosed by a [lipid bilayer]. Vesicles can form naturally, for example, during the processes of secretion (exocytosis), uptake (phagocytosis and endocytosis) and transport of materials within the cytoplasm.
Concentration Gradient
The formal definition of concentration gradient is the process of particles, which are sometimes called solutes, moving through a solution or gas from an area of higher number of particles to an area of lower number of particles. The areas are typically separated by a membrane.
Equilibrium
The state in which the concentrations of the diffusing substance in the two compartments are the same or become equal.
Turgor Pressure
Turgor pressure pushes the plasma membrane against the cell wall of plant, bacteria, and fungi cells as well as those protist cells which have cell walls.
Phagocytes
Phagocytes are cells that protect the body by ingesting (phagocytosing) harmful foreign particles, bacteria, and dead or dying cells. Their name comes from the Greek phagein, “to eat” or “devour”, and “-cyte”, the suffix in biology denoting “cell”, from the Greek kutos, “hollow vessel”.
Endocytosis
Endocytosis is a form of active transport in which a cell transports molecules (such as proteins) into the cell (endo- + cytosis) by engulfing them in an energy-using process.
Ion channel
Ion channels are pore-forming membrane proteins whose functions include establishing a resting membrane potential, shaping action potentials and other electrical signals by gating the flow of ions across the cell membrane, controlling the flow of ions across secretory and epithelial cells, and regulating cell volume.
Cytolysis
Cytolysis, or osmotic lysis, occurs when a cell bursts due to an osmotic imbalance that has caused excess water to move into the cell.
Isotonic
The term isotonic may refer to; Isotonic (exercise physiology), a type of muscle contraction. Isotonic regression, a type of numerical analysis. Isotonic, one of three types of tonicity that characterize a solution’s concentration. A sports drink that contains similar concentrations of salt and sugar to the human body.
Hypotonic
In a hypotonic solution the total molar concentration of all dissolved solute particles is less than that of another solution or less than that of a cell. If concentrations of dissolved solutes are less outside the cell than inside, the concentration of water outside is correspondingly greater.