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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]
4-Hydroxyphenylpyruvate dioxygenase (HPPD) is an enzyme found in both plants and animals, which catalyzes the catabolism of the amino acid tyrosine. [4] Preventing the breakdown of tyrosine has three negative consequences: the excess of tyrosine stunts growth; the plant suffers oxidative damage due to lack of tocopherols (vitamin E); and ...
Pectinase enzymes used today are naturally produced by fungi and yeasts (50%), insects, bacteria and microbes (35%) and various plants (15%), [4] but cannot be synthesized by animal or human cells. [5] In plants, pectinase enzymes hydrolyze pectin that is found in the cell wall, allowing for new growth and changes to be made.
Top: enzyme (E) accelerates conversion of substrates (S) to products (P). Bottom: by binding to the enzyme, inhibitor (I) blocks binding of substrate. Binding site shown in blue checkerboard, substrate as black rectangle, and inhibitor as green rounded rectangle. An enzyme inhibitor is a molecule that binds to an enzyme and blocks its activity.
Once boron has been absorbed by the plant and incorporated into the various structures that require boron, the plant is unable to disassemble these structures and re-transport boron through the plant resulting in boron being a non-mobile nutrient. Due to translocation difficulties the youngest leaves often show deficiency symptoms first. [5]
The enzyme is a homotetramer with three domains in each monomer and four active sites per homotetramer. Point mutations in adenylosuccinate that cause lowered enzymatic activity cause clinical symptoms that mark the condition adenylosuccinate lyase deficiency. This protein may use the morpheein model of allosteric regulation. [7]
Ribonucleotide reductase (RNR), also known as ribonucleoside diphosphate reductase, is an enzyme that catalyzes the formation of deoxyribonucleotides from ribonucleotides. [1] [2] It catalyzes this formation by removing the 2'-hydroxyl group of the ribose ring of nucleoside diphosphates (or triphosphates depending on the class of RNR).
Molybdenum deficiency symptoms in most plants are associated with a build-up of nitrate in the affected plant part. This is a result of poor nitrate reductase activity. Symptoms include: [1] [2] pale leaves with interveinal and marginal chlorosis (yellowing) and necrosis (scald); the whiptail disorder in Brassica crops (especially cauliflower);