Biology Part. 2 Flashcards
A description of membrane structure, depicting a cellular membrane as a mosaic of diverse protein molecules embedded in a fluid bilayer made of phospholipid molecules.
Fluid Mosaic
The principle of conservation of energy. Energy can be transferred and transformed, but it cannot be created or destroyed.
First Law of Thermodynamics
Thermal energy; the amount of energy associated with the movement of the atoms and molecules in a body of matter. Heat is energy in its most random form.
Heat
Referring to a solution that, when surrounding a cell, will cause the cell to lose water.
Hypertonic Solution
Referring to a solution that, when surrounding a cell, will cause the cell to take up water.
Hypotonic Solution
The change in shape of the active site of an enzyme, induced by entry of the substrate so that it binds more snugly to the substrate.
Induced Fit
A solution having the same solute concentration as another solution, thus having no effect on passage of water in or out of the cell.
Isotonic Solution
The energy of motion; the energy of a mass of matter that is moving. Moving matter does work by imparting motion to other matter.
Kinetic Energy
The totality of an organism’s chemical reactions.
Metabolism
A substance that impedes the activity of an enzyme without entering an active site. By binding elsewhere on the enzyme, a noncompetitive inhibitor changes the shape of the enzyme so that the active site no longer functions.
Noncompetitive Inhibitor
Method by which organisms regulate solute concentrations and balance the gain and loss of wate
Osmoregulation
The diffusion of water across a selectively permeable membrane.
Osmosis
The diffusion of a substance across a biological membrane, without any input of energy.
Passive Transport
Cellular “eating”; a type of endocytosis whereby a cell engulfs macromolecules, other cells, or particles into its cytoplasm.
Phagocytosis
The transfer of a phosphate group, usually from ATP, to a molecule. Nearly all cellular work depends on ATP energizing other molecules by phosphorylation.
Phosphorylation
Cellular “drinking”; a type of endocytosis in which the cell takes fluid and dissolved solutes into small membranous vesicles.
Pinocytosis
The energy that matter possesses because of its location or arrangement. Water behind a dam and chemical bonds possess potential energy.
Potential Energy
The movement of specific molecules into a cell by the inward budding of membranous vesicles. The vesicles contain proteins with receptor sites specific to the molecules being taken in.
Receptor Mediated Endocytosis
The principle whereby every energy conversion reduces the order of the universe, increasing its entropy. Ordered forms of energy are at least partly converted to heat.
Second Law of Thermodynamics
A property of biological membranes that allows some substances to cross more easily than others and blocks the passage of other substances altogether.
Selective Permeability
1) A specific substance (reactant) on which an enzyme acts. Each enzyme recognizes only the specific substrate or substrates of the reaction it catalyzes. (2) A surface in or on which an organism lives.
Substrate
The study of energy transformation that occurs in a collection of matter.
Thermodynamics
The ability of a solution surrounding a cell to cause that cell to gain or lose water.
Tonicity
