Term
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Definition
| In the general theory of enzyme catalysis, the tertiary structure of an enzyme forms a pocket in which the reactants are brought together in the proper orientation for bond formation. |
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Definition
| The main source of energy available to cells to drive energy-requiring reactions that ordinarily would not proceed spontaneously. |
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Term
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Definition
| In the process of ATP driving energy-requiring reactions, one of the three phosphate groups of ATP is split off, yielding this and inorganic phosphate (Pi). |
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Term
| Activation energy barrier |
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Definition
| In order to bond to one another, the two reactants must meet each other with sufficient energy to overcome an this required for a bond to form. |
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Term
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Definition
| Excess acic in extracellular fluid. |
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Term
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Definition
| Excess base in extracellular fluid. |
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Term
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Definition
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Term
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Definition
| A substance that decreases the pH of a solution. |
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Term
| Allosteric Phosphoylation |
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Definition
| At another site other than the active site, attachment of a phosphate group [PO4] at a specific site on the protein by another enzyme, kinase. |
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Term
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Definition
| A molecule that is most stable when its head is in an aqueous environment and its tail in a nonpolar environment. |
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Term
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Definition
| Organic compounds that contain at least one carbon atom that is bonded simultaneously to carboxyl group; amino group; hydrogen atom; and a side chain of varying complexity, the structure of which determines its type. The side chain may be polar, nonpolar, acidic, basic, or aromatic. |
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Term
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Definition
| In an ionic bond, the acceptor atom that is negatively charged. |
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Term
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Definition
| Energy captured in catabolic processes is used to assemble simple molecules from food into the proteins, nucleic acids, lipids, and other macromolecules needed for cellular growth and maintenance. |
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Term
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Definition
| A major principle of enzyme regulation within cells is that the activity of an enzyme can be regulated—increased or decreased, depending on the particular enzyme and binding site—by phosphorylation (attachment of a phosphate group [PO4] at a specific allosteric site on the protein by another enzyme called a kinase). Likewise, some key enzymatic reactions are regulated by allosteric inhibition of the product of the reaction acting on the enzyme. |
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Term
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Definition
| A substance that increases the pH of a solution. |
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Term
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Definition
| The sum of the number of protons and neutrons in its nucleus. |
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Term
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Definition
| The basic units of all matter. |
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Term
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Definition
| A system of reactants that acts to minimize changes in pH. |
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Term
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Definition
| No matter what the compound,one mole contains 6.023*10^23 of molecules. |
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Term
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Definition
| The number of protons in the nucleus of atom that establishes the chemical identity of the atom. |
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Term
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Definition
| Processes that form or break chemical bonds, resulting in the formation of new compounds. |
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Term
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Definition
| A series of reactions in which the cell extracts energy from chemical sources in the environment. |
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Term
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Definition
| In an ionic bond, the donor atom that is positively charged. |
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Term
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Definition
| Forms when there is interaction between the orbitals of the outermost energy levels of two atoms. |
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Term
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Definition
| Substances that promote reactions by lowering their activation energy barriers without themselves being changed in the reaction. |
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Term
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Definition
| An oxidation process in which ATP used in cellular activities is rapidly regenerated by the cell's energy metabolism. |
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Term
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Definition
| A nuclear structure consisting of a double stand of DNA together with a large number of associated smaller molecules that are involved in regulation of gene expression and chromosomal structure. |
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Term
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Definition
| A suspension whose particles are so small that intermolecular forces can overcome the force of gravity and keep the particles suspended. |
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Term
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Definition
| The strongest form of atomic bonding in which the bonded partners share one or more electrons to complete their outer energy levels. |
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Term
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Definition
| Atoms connected by a polar bond. |
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Term
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Definition
| A reaction in which the removal of a H+ from one reactant and an OH- from the other simultaneously allows the formation of a molecule of water and a bond between the two reactants, creating disaccharides from monosaccharides. |
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Term
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Definition
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Term
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Definition
| Substances composed of molecules of the same type. |
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Term
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Definition
| When the tertiary structure of enzymes begin to unravel. |
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Term
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Definition
| Formed from monosaccharides by dehydration reaction. |
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Term
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Definition
| The opposite of synthesis reactions, taking the form AB A+B |
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Term
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Definition
| Compounds that incorporate ionic bonds are typically separated into their component ions in water solution. |
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Term
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Definition
| An electron orbital arragned around the nucleus of an atom. |
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Term
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Definition
| Those atoms that are far from having a filled outer level can find stability most easily by moving in the direction of emptying their outermost energy levels. |
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Term
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Definition
| Those atoms with nearly full outer levels tend to acquire electrons to fill their orbitals. |
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Term
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Definition
| A protein that acts as the body’s catalysts, permitting it to carry out at body temperature reactions that would require a much higher temperature if conducted without catalysis. |
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Term
| DNA (Deoxyribonucleic acid) |
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Definition
| One type of nucleic acid in which two polynucleotide strands are twined into a double helix. It is the form in which information about the primary sequences of proteins is passed to daughter cells in cell division during growth and development and in the formation of reproductive cells in the gonads. |
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Term
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Definition
| Expressing solute concentrations as a measure of the number of charges per unit volume rather than the number of particles. |
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Term
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Definition
| A polysaccharide that has an important role as an energy store within cells. |
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Term
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Definition
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Term
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Definition
| Pieces of RNA that remain after editing that are spliced back together during the posttransciptional processing. |
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Term
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Definition
| Chains of carbons terminating a carboxyl group. |
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Term
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Definition
| Lipids with covalently bound carbohydrates - The bound carbohydrate chain may be from one to seven or more monosaccharides long. |
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Term
| Equilibrium constant (Keq) |
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Definition
| The characteristic ratio of reactants to product at equilibrium. |
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Term
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Definition
| Present in all cells except gametes; the members of each pair are of similar size and contain genes that are related, but not necessarily identical. |
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Term
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Definition
| Parts that will be edited and not appear in the final RNA transcript. |
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Term
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Definition
| The result of the fact that hydrogen-nitrogen and hydrogen-oxygen bonds are polar covalent bonds. A hydrogen so bonded has a small positive charge because the electron it is sharing spends most of its time with the oxygen or nitrogen. |
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Definition
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Term
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Definition
| An ion in solution surrounded by a shell of water molecules oriented with their electrically opposite poles towards the ion. |
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Term
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Definition
| Remove repressors and prevent their binding to the DNA. |
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Term
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Definition
| Formed when an element that readily gives up electrons reacts with an element that readily accepts them. The result is that one or more electrons are transferred from the donor to the acceptor. |
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Term
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Definition
| A reproductive cell that has twenty-two somatic chromosomes and either an X or a Y chromosome. |
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Term
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Definition
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Term
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Definition
| Different forms of the same element having the same number of protons but differing in the number of neutrons. |
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Term
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Definition
| Digest condemned proteins within the endocytotic vesicle, making the proteins’ component amino acids available for reuse. |
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Term
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Definition
| Enzymes that exist in multiple forms with different enzymatic properties. |
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Term
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Definition
| The major nonpolar, water-insoluble organic molecules in the body. |
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Term
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Definition
| Different forms of molecules with the same chemical formula. |
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Term
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Definition
| Enzymes that exist in multiple forms with different enzymatic properties, and are the products of separate genes. Tissues may express one specific isoform or may generate a mixture of isoforms. |
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Term
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Definition
| The formation of reproductive cells in the gonads. |
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Term
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Definition
| Structures that result from attachment of atoms to one another by chemical bonds. |
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Term
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Definition
| Within the secondary structure of proteins, established by folding, coiling, or pleating the chain at particular regions of the primary sequence to form characteristic simple shapes. These effects are primarily due to the formation of hydrogen bonds and van der Waals interactions between different parts of the primary structure. |
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Term
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Definition
| Molecules that contain six carbons arranged in a six-sided ring (hexoses) or a five-sided ring (pentoses). They are one of the chief starting materials for energy metabolism since they can be oxidized with release of considerable energy. |
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Term
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Definition
| The total of all of the atomic weights of its components expressed in grams. |
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Term
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Definition
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Term
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Definition
| Carries the information for protein sequences from the nucleus to the protein synthesis machinery in the cytoplasm. |
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Term
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Definition
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Term
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Definition
| For a solution, the number of grams of solute per liter of water,divided by solute's molecular weight. |
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Term
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Definition
| A covalent bond resulting from bonded atoms with equally strong electron donors and acceptors: each shared electron spends about the same amount of time with each of the two bonded atoms. |
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Term
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Definition
| Molecules consisting of a five-carbon sugar (which is deoxyribose in DNA and ribose in RNA), a phosphate group, and a nitrogen-containing aromatic base. |
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Term
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Definition
| Spaces in which there is a 90 percent probability of finding a particular electron at any particular instant. Each orbital is full when it contains two electrons. |
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Term
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Definition
| Linear chains of nucleotides strung together in a sequence that carries information (DNA and RNA). |
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Term
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Definition
| In redox reactions, one atom donates one or more electrons to another atom. The donor atom becomes this, and the recipient becomes reduced. Such reactions are important in the energy metabolism of cells because, in many cases, the chemical energy potential of foodstuffs is due to their ability to release energy when this happens. |
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Term
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Definition
| In the atom, it contains a variable number of protons and neutrons. |
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Term
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Definition
| Compounds that contain carbon and hydrogen. |
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Term
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Definition
| Uncharged particles in the nucleus of the atom. |
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Term
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Definition
| Chains of sugars, such as starch and glycogen. |
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Term
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Definition
| Major components of the plasma membrane surrounding cells and of other membranes within the cellular interior. They are the result of replacing one of the fatty acids of a triacylglycerol with a phosphate group bound to a polar molecule. |
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Term
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Definition
| Join proteins in chains of amino acids. |
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Term
| Posttranslational processing |
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Definition
| During the translation of the nucleotide sequence into a corresponding amino acid sequence, sometimes parts of the amino acid sequence are clipped off or two or more polypeptides are attached together to form a functional complex. |
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Term
| Posttranscriptional processing |
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Definition
| In the first step of gene expression, the two-stranded DNA is unwound at the appropriate spot and a complementary strand of mRNA is assembled using one of the strands as a template. This process is catalyzed by an enzyme called RNA polymerase. Next, the primary transcript must be edited, for it contains parts, called introns, that will not appear in the final transcript. The pieces of RNA that remain after editing, called exons, are spliced back together. |
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Term
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Definition
| The first, most elementary level in the structure of proteins. This is simply the order of amino acids in the protein chain. |
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Term
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Definition
| Pure water at standard temperature has hydrogen and hydroxyl ion concentrations of 10-7mEq/l each. It is convenient to express the hydrogen ion concentration as a logarithm: log (1/[H+]). This results in a pH scale that runs from 1–14. |
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Term
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Definition
| The working copies of individual sentences that are made in the form of a single strand of complementary messenger RNA (mRNA). |
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Term
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Definition
| Fully structured proteins that may associate with one another to form functional units (e.g., the enzyme, lactate dehydrogenase). |
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Term
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Definition
| Secreted by the lungs, interfering with the water-water interactions and reduces surface tension. |
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Term
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Definition
| Derivatives of arachidonic acid, a twenty-carbon fatty acid. |
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Term
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Definition
| Isotopes that are unstable and undergo a decay process in which the atoms reach a stable state by emitting high-energy particles from their nuclei. |
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Term
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Definition
| Each gene has a sequence at its head end. Transcription of a gene begins when RNA polymerase binds to this site and continues until the polymerase reaches the terminator site. This sequence and terminator sequences simply act to attach and detach the polymerase—they don’t get transcribed. |
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Term
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Definition
| In a chemical reaction, elements or compounds that were not present in that form initially. |
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Term
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Definition
| At the molecular level, this term applies to molecules that recognize signal molecules of specific types and assist in bringing about the signal’s effect on the target cells. |
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Term
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Definition
| Positively charged particles in the nucleus of an atom. |
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Term
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Definition
| In (oxidation-reduction) reactions, one atom donates one or more electrons to another atom. The donor atom becomes oxidized, and the recipient becomes reduced. |
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Term
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Definition
| One type of nucleic acid, curled into a single spiral helix, comprising linear chains of nucleotides strung together in a sequence that carries information. Uracil (U) appears instead of thymidine. |
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Term
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Definition
| In the structure of proteins, this level is established by folding, coiling, or pleating the chain at particular regions of the primary sequence to form characteristic simple shapes (motifs). |
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Term
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Definition
| An endoplasmic reticulum studded with ribosomes and is a visible sign that the cell is actively synthesizing such proteins. |
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Term
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Definition
| Protein synthesizing organelles. |
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Term
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Definition
| An enzyme that catalyzes the process in the first step of gene expression: the two-stranded DNA is unwound at the appropriate spot and a complementary strand of mRNA is assembled using one of the strands as a template. |
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Term
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Definition
| One of three functional classes of RNA, largely composing the ribosomes. |
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Term
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Definition
| Proteins that may block the attachment of polymerase to the promoter by attaching to the promoter site. |
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Term
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Definition
| A measure of the maximum amount of that substance that can be held in solution by a given solute under standard conditions of temperature and pressure. |
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Term
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Definition
| Combine two or more elements or compounds to form a new compound according to the form A + B AB. |
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Term
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Definition
| A fluid in which other substances (the solutes) can be dissolved. |
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Term
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Definition
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Term
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Definition
| Variant forms of molecules that differ in the orientation of a key functional group. |
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Term
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Definition
| Causes the ribosome translating the mRNA to attach itself to the endoplasmic reticulum. |
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Term
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Definition
| Particles with dimensions exceeding that of the typical molecule may be dispersed in water. |
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Term
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Definition
| Substances that can be dissolved in a solvent. |
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Term
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Definition
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Term
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Definition
| The major form of stored lipid in the body, making up the majority of the fat in adipose cells. |
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Term
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Definition
| Each gene has a sequence at its tail end. Transcription of a gene begins when RNA polymerase binds to the promoter site and continues until the polymerase reaches this site. The promoter and these sequences simply act to attach and detach the polymerase—they don’t get transcribed. |
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Term
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Definition
| Responsible for recognizing particular amino acids and adding them to the growing polypeptide chain in the order specified by the mRNA. |
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Term
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Definition
| The number of electrons an element can accept or donate. |
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Term
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Definition
| A molecule that labels proteins that are to undergo destruction. |
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Term
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Definition
| In RNA, a nitrogen-containing aromatic base that appears instead of thymidine (DNA). |
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Term
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Definition
| An electron in an outer energy level that an element can donate. |
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Term
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Definition
| Attractive forces that develop between molecules or between different parts of the same large molecule as a result of the fact that the distribution of electrons in each molecule varies over time. |
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