Vocabulary 3 Flashcards
Turgor Pressure
When a plant cell stores ions, sugars and other solutes in its vacuole, this causes an influx of water. The influx of water results in a large turgor pressure exerted on the plant cell wall. This makes plant cells to become turgid, thus, helping the plants to stand upright, and do not wilt.
Plasmolysis
The shrinking of protoplasm away from the cell wall of a plant or bacterium due to water loss from osmosis, thereby resulting in gaps between the cell wall and cell membrane.
Osmosis
Diffusion of fluid through a semipermeable membrane from a solution with a low solute concentration to a solution with a higher solute concentration until there is an equal concentration of fluid on both sides of the membrane.
Pinocytosis
A process of taking in fluid together with its contents into the cell by forming narrow channels through its membrane that pinch off into vesicles, and fuse with lysosomes that hydrolyze or break down contents.
Cytolysis
Cytolysis or osmotic lysis occurs in animal cells and certain bacteria, especially when the cells are exposed to a hypotonic environment, causing the water to move into the cell, thereby increasing or expanding the cell. If the cell membrane cannot regulate or hold the excessive influx of water, the cell will eventually burst. Osmotic lysis does not occur in plant cells because of the cell wall that contains the turgor pressure.
Endocytosis
A process of cellular ingestion by which the plasma membrane folds inward to bring substances into the cell.
Exocytosis
The process in which the cell releases materials to the outside by discharging them as membrane-bounded vesicles passing through the cell membrane.
Carrier Protein
A protein that transports specific substance through intracellular compartments, into the extracellular fluid, or across the cell membrane.
Passive Transport
A kind of transport by which ions or molecules move along a concentration gradient, which means movement from an area of higher concentration to an area of lower concentration.
Diffusion
The passive movement of molecules or particles along a concentration gradient, or from regions of higher to regions of lower concentration.
Facilitated Diffusion
Process whereby a substance passes through a membrane with a aid of an intermediary or a facilitator.
Ion Channel
A single protein or protein complex that traverses the lipid bilayer of cell membrane and form a channel to facilitate the movement of ions through the membrane according to their electrochemical gradient.
Contractile Gradient
A difference between concentrations in a space.
Hypertonic
Having the higher osmotic pressure of two solutions.
Hypotonic
Having a lesser degree of tone or tension.
Equilibrium
The condition in which all acting influences are balanced or canceled by equal opposing forces, resulting in a stable system.
Isotonic
Having equal tension.
Contractile Vacuole
A membrane-bound organelle found in certain protists that pumps fluid in a cyclical manner from within the cell to the outside by alternately filling and then contracting to release its contents at various points on the surface of the cell. It functions in maintaining osmotic equilibrium.
Phagocyte
A cell, such as a white blood cell, that engulfs and absorbs waste material, harmful microorganisms, or other foreign bodies in the bloodstream and tissues.
Active Transport
A kind of transport wherein ions or molecules move against a concentration gradient, which means movement in the direction opposite that of diffusion – or – movement from an area of lower concentration to an area of higher concentration. Hence, this process will require expenditure of energy, and the assistance of a type of protein called a carrier protein.
Vesicle
A bubble-like membranous structure that stores and transports cellular products, and digests metabolic wastes within the cell; an intracellular membranous sac that is separated from the cytosol by at least one lipid bilayer.
Phagocytosis
The process of engulfing and ingestion of particles by the cell or a phagocyte (e.g. macrophage) to form a phagosome (or food vacuole), which in turn fuse with lysosome and become phagolysosome where the engulfed material is eventually digested or degraded and either released extracellularly via exocytosis, or released intracellularly to undergo further processing.
Sodium Potassium Pump
A mechanism of active transport that moves potassium ions into and sodium ions out of a cell.
