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In biochemistry, denaturation is a process in which proteins or nucleic acids lose folded structure present in their native state due to various factors, including application of some external stress or compound, such as a strong acid or base, a concentrated inorganic salt, an organic solvent (e.g., alcohol or chloroform), agitation and radiation, or heat. [3]
Enzymes are not rigid, static structures; instead they have complex internal dynamic motions – that is, movements of parts of the enzyme's structure such as individual amino acid residues, groups of residues forming a protein loop or unit of secondary structure, or even an entire protein domain.
Superoxide dismutase (SOD, EC 1.15.1.1) is an enzyme that alternately catalyzes the dismutation (or partitioning) of the superoxide (O − 2) anion radical into normal molecular oxygen (O 2) and hydrogen peroxide (H 2 O 2). Superoxide is produced as a by-product of oxygen metabolism and, if not regulated, causes many types of cell damage. [2]
Biosynthesis, i.e., chemical synthesis occurring in biological contexts, is a term most often referring to multi-step, enzyme-catalyzed processes where chemical substances absorbed as nutrients (or previously converted through biosynthesis) serve as enzyme substrates, with conversion by the living organism either into simpler or more complex ...
The cooperative unit size is the number of adjacent bases that tend to unwind as a single unit due to the effects of positive cooperativity. This phenomenon applies to other types of chain molecules as well, such as the folding and unfolding of proteins and in the "melting" of phospholipid chains that make up the membranes of cells .
Most enzymes have deeply buried active sites, which can be accessed by a substrate via access channels. [3] There are three proposed models of how enzymes fit their specific substrate: the lock and key model, the induced fit model, and the conformational selection model. The latter two are not mutually exclusive: conformational selection can be ...
Bacteria generally have one bi-functional enzyme, but archaea and eukaryotes usually employ two distinct enzymes. [9] Current research indicates that distinct isoforms exist in the cytosol and mitochondria. [9] It seems that FAD is synthesized in both locations and potentially transported where needed. [11]
Metabolism (/ m ə ˈ t æ b ə l ɪ z ə m /, from Greek: μεταβολή metabolē, "change") is the set of life-sustaining chemical reactions in organisms.The three main functions of metabolism are: the conversion of the energy in food to energy available to run cellular processes; the conversion of food to building blocks of proteins, lipids, nucleic acids, and some carbohydrates; and the ...