A system of ranking and organizing things or people, where each element of the system (except for the top element) is subordinate to a single other element.
A type of strong chemical bond in which two atoms share one of more pairs of valence electrons.
A type of weak chemical bond formed when the slightly positive hydrogen atom of a polar covalent bond in one molecule is attracted to the slightly negative atom of a polar covalent bond in another molecule.
Molecules with opposit charges on opposite sides (example = water).
Having an aversion to water; tending to coalesce and form droplets in water (example = motor oil).
An atom that has gained or lost electrons, thus acquiring a charge.
A single proton with a charge of 1+. The dissociation of a water molecule leads to the generation of a hydroxide ion and a hydrogen ion.
A measure of hydrogen ion concentration equal to -log[H+] and ranging in value from 0 to 14.
A long molecule consisting of many similar or identical monomers linked together.
A giant molecule formed by the joining of smaller molecules, usually by a condensation reaction (examples = polysaccharides, proteins, nucleic acids).
A chemical process that lyses, or splits, molecules by the addition of water.
A chemical reaction in which two molecules covalently bond to each other with the removal of a water molecule.
A three-dimensional biological polymer constructed from a set of 20 different monomers called amino acids.
A polymer (chain) of many amino acids linked together by peptide bonds.
The makeup of a polypeptide, also made from amino acids.
An organic molecule possessing both carboxyl and amino groups. Amino acids serve as the monomers of proteins.
A polymer of up to over 1000 monosaccharides, formed by dehydration reactions.
The simplest carbohydrate, active alone or serving as a monomer for disaccharides and polysaccharides. Also known as simple sugars, the molecular formulas of monosaccharides are generally some multiple of CH20.
Either a monosaccharide, disaccharide, or polysaccharide.
A polymer (polynucleotide) consisting of many nucleotide monomers; serves as a blueprint for proteins and, through the actions of proteins, for all cellular activities. The types are DNA and RNA.
The building block of a nucleic acid, consisting of a five-carbon sugar covalently bonded to a nitrogenous bas and a phosphate group.
A functional group important in energy transfer (ATP and ADP).
Molecules that are constituents of the inner bilayer of biological membranes, having a polar, hydrophilic head and a nonpolar, hydrophobic tail.
The level of protein structure referring to the specific sequence of amino acids.
The localized, repetitive coiling or folding of the polypeptide backbone of a protein due to hydrogen bond formation between peptide linkages.
Irregular contortions of a protein molecule due to interactions of side chains involved in hydrophobic interactions, ionic bonds, hydrogen bonds, and disulfide bridges.
The paticular shape of a complex, aggregate protein, defined by the characteristc three-dimensional arrangement of its constituent subunits, each a polypeptide.
In proteins, a process in which a protein unravels and loses its native conformation, thereby becoming biologically inactive. Denaturation occurs under extreme conditions in pH, salt, concentration, and temperature.
Opposite of denaturation.
A molecule that has both a hydrophilic region and a hydrophobic region.
An electrically charged particle formed by an aggregate of molecules and occuring in certain colloidal electrolyte solutions.
A membrane surrounding the cell. It does differ between plant membrae and animal membrane.
Membrane that allows vertain particles to flow freely through the membrane without any energy required.
The tendenc of molecules of any substance to spread out evenly into the available space.
The diffusion of water across a selectively permeable membrane.
Very firm; health state for most plant cells.
Limp due to isotonic environment, thus having no water enter and stay in.
A cell involved in plasmolysis, which is when the cell is immersed in a hypertonic environment, and the cell will lose water to its surroundings and shrink. The plasma membrane pulls away from the cell wall, also.
The cell wall will lose water to its environment, shrivel, and probably die.
Water will enter the cell faster than it can leave, and the cell wall will burst (lyse) like an overfilled balloon.
The diffusion of a substance across a biological membrane.
The spontaneous passage of molecules and ions, bound to specific carrier proteins, across a biological membrane down their concentration gradients. It moves from high to low concentration.
The movement of a substance across a biological membrane against its concentration or electrochemical gradient with the help of energy input and specific transport proteins. It moves from low to high concentration.
The coupling of the "downhill" diffusion of one substance to the "uphill" transport of another against its own concentration gradient.
Transports one ion into the membrane and takes another ion out. The protein changes its shape so the ion can fit in it for transport.
A type of ion pump that transfers K+ ions into the cell and Na+ ions out of the cell.
Hydrogen ion pump
A hydrogen ion is forced out of the cell by ATP through a protein and comes back into the cell with a sucrose molecule. The hydrogen ion helps the sucrose enter the cell and keeps the cell alive.
The cellular secretion of macromolecules by the fusion of vesicles with the plasma membrane.
The cellular uptake of macromolecules and particular substances by localized regions of the plasma membrane that surround the substance and pinch off to form an intracellular vesicle.
A sac made of membrane inside of cells.