What's the difference between essential and methenyl?
Essential
Definition:
(a.) Belonging to the essence, or that which makes an object, or class of objects, what it is.
(a.) Hence, really existing; existent.
(a.) Important in the highest degree; indispensable to the attainment of an object; indispensably necessary.
(a.) Containing the essence or characteristic portion of a substance, as of a plant; highly rectified; pure; hence, unmixed; as, an essential oil.
(a.) Necessary; indispensable; -- said of those tones which constitute a chord, in distinction from ornamental or passing tones.
(a.) Idiopathic; independent of other diseases.
Example Sentences:
(1) However, medicines have an important part to play, and it is now generally agreed that for the very poor populations medicines should be restricted to those on an 'essential drugs list' and should be made available as cheaply as possible.
(2) The results of the evaluation confirm that most problems seen by first level medical personnel in developing countries are simple, repetitive, and treatable at home or by a paramedical worker with a few safe, essential drugs, thus avoiding unnecessary visits to a doctor.
(3) Nucleotide, which is essential for catalysis, greatly enhances the binding of IpOHA by the reductoisomerase, with NADPH (normally present during the enzyme's rearrangement step, i.e., conversion of a beta-keto acid into an alpha-keto acid, in either the forward or reverse physiological reactions) being more effective than NADP.
(4) Community involvement is a key element of the Primary Health Care (PHC) approach, and thus an essential topic on a course for managers of Primary Health Care programmes.
(5) No significant fatty acid binding by proteins was detected in S. cerevisiae, even when grown on a fatty acid-rich medium, thus indicating that such proteins are not essential to fatty acid metabolism.
(6) The UK's standard position on ICC indictees is to avoid all contact unless "essential".
(7) In spite of important differences in size, chemical composition, polymer density, and configuration, biological macromolecules indeed manifest some of the essential physical-chemical properties of gels.
(8) Most cis AB sera have anti-B activity, essentially at 4 degrees C. In saliva A and H substances are found in normal amounts but B substance is only evidenced by inhibition of autologous cells agglutination.
(9) Treatment with trypsin gave essentially one radioactive peptide, the active site peptide, of approximately 2300 molecular weight.
(10) We conclude that this enzyme is essentially identical to the native enzyme and should be very useful in the future study of this important hydroxylase.
(11) Thus serum ionized calcium in untreated essential hypertensive patients may predict the blood pressure response to the slow calcium channel blocker verapamil.
(12) The effects of supervised mild aerobic exercise at the work load of the blood lactate threshold for 10 weeks on serum lipids and apolipoproteins were studied in 24 patients with essential hypertension.
(13) No other essential regulatory sequence is located further upstream.
(14) Based on the results of the Community AIM Exploratory Action, further collaborative work is required at EEC level to create an Integrated Health Information Environment (IHE) allowing essentially for integration, modularity and security.
(15) Ovarian vein sampling for androgen was essential in locating this patient's microscopic tumor.
(16) After approximately 20 in vitro passages, Chinese hamster kidney (CHK) cell cultures transformed upon exposure to different strains of SV 40 can show a diploid modal chromosome number of 22 with chromosome counts exclusively or essentially in the diploid range (20-25).
(17) An official from Cafcass, the children and family court advisory service, tried to persuade the child in several interviews, but eventually the official told the court that further persuasion was inappropriate and essentially abusive.
(18) Of 55 new open reading frames analysed by gene disruption, three are essential genes; of 42 non-essential genes that were tested, 14 show some discernible effect on phenotype and the remaining 28 have no overt function.
(19) Essential characteristics of the composite bone cement included a homogeneous and uniform fiber distribution, and a minimal increase in apparent viscosity of the polymerizing cement.
(20) The median blood levels were lower in hyperacidic subjects and higher in hypoacidic patients; the urinary excretion of the digitalis compound showed no essential differences.
Methenyl
Definition:
(n.) The hypothetical hydrocarbon radical CH, regarded as an essential residue of certain organic compounds.
Example Sentences:
(1) The enzyme catalyzes the hydrolysis of methenyl-H4MPT to formyltetrahydromethanopterin (formyl-H4MPT).
(2) A DNA clone complementary to the messenger RNA encoding the human trifunctional enzyme 5,10-methylenetetrahydrofolate dehydrogenase-5,10-methenyl-tetrahydrofolate cyclohydrolase-10-formyltetrahydrofolate synthetase has been isolated from a lambda gt10 library.
(3) The relative configuration of the pterin moiety of 5,6,7,8-tetrahydromethanopterin 1, a coenzyme isolated from methanogenic archaea, has been determined by two-dimensional NMR spectroscopy of N5,N10-methenyl-5,6,7,8-tetrahydromethanopterin 2 to be rel-(6R; 7S; 11R).
(4) We also measured the activities of another three enzymes of the folic acid cycle, viz., 5,10-methylene-H4folate dehydrogenase, 10-formyl-H4folate synthetase, and 5,10-methenyl-H4folate cyclohydrolase, as well as the enzyme cystathionine beta-synthase.
(5) Evaluation of the reaction equilibrium indicated that the methenyl derivative was favored over 5-formyltetrahydromethanopterin, with a much higher equilibrium constant than for the analogous reaction of tetrahydrofolate derivatives.
(6) Escherichia coli DNA photolyase contains 1,5-dihydro-FAD (FADH2) plus 5,10-methenyl-tetrahydrofolate (5,10-CH+-H4folate).
(7) IR spectrophotometry of the crystals embedded in potassium bromide disc showed specific spectra in the 1400-800 cm-1 wave number range and typical peaks on wave number assigned for hydroxy or amine (3420 cm-1), aromatic hydrogen (3060 cm-1), methyl, methylenic, or methenyl (2960-2860 cm-1), and carbonyl (1715 cm-1) groups can be demonstrated.
(8) The three activities are thus shown to reside in a protein composed of two apparently identical subunits, and the trivial name formyl-methenyl-methylenetetrahydrofolate synthetase(combined) is proposed for this enzyme to suggest the multiple catalytic activities associated with the single protein species.
(9) A method has been devised for the cytochemical demonstration of 5-formyl tetrahydrofolate cyclodehydrase and 5,10-methenyl tetrahydrofolate cyclohydrolase activity which uses 5-formyl tetrahydrofolate or 5,10-methenyl tetrahydrofolate as substrate respectively, blocking possible interferences by other enzymes, and allows the nonenzymatic reduction of nitro-blue tetrazolium by 5,10-methenyl tetrahydrofolate formed by the action of the cyclodehydrase on the substrate 5-formyl tetrahydrofolate, and by 10-formyl tetrahydrofolate formed by the action of cyclohydrolase on the substrate 5,10-methenyl tetrahydrofolate, thus revealing intracellular sites of enzyme activity.
(10) In eucaryotes, 10-formyltetrahydrofolate (formyl-THF) synthetase, 5,10-methenyl-THF cyclohydrolase, and NADP(+)-dependent 5,10-methylene-THF dehydrogenase activities are present on a single polypeptide termed C1-THF synthase.
(11) A second enzyme, cyclohydrolase, converts 5,10-methenyl tetrahydrofolate to 10-formyl tetrahydrofolate.
(12) 5,10[14C]methylene H4folate and 5,10[14C]methenyl H4folate also serve as precursors of formic acid in the poison gland, suggesting that they are intermediates in the pathway.
(13) C1-tetrahydrofolate (THF) synthase is a trifunctional protein possessing the activities 10-formyl-THF synthetase, 5,10-methenyl-THF cyclohydrolase, and 5,10-methylene-THF dehydrogenase.
(14) The product of formyl transfer by the purified enzyme was shown by a number of criteria to be 5-formyl-H4MPT, as opposed to 10-formyl-H4MPT or 5,10-methenyl-H4MPT.
(15) When methanogenesis from the non-physiological donors was followed under a nitrogen atmosphere, the C1 moiety from each compound underwent a disproportionation, forming methenyl-H4MPT+ and methane.
(16) The enzyme 5-formyl tetrahydrofolate cyclodehydrase plays an important role in the conversion of 5-formyl tetrahydrofolate to 5,10-methenyl tetrahydrofolate.
(17) Similarly, the nonenzymatic hydrolysis of methenyl-H4MPT is highly dependent on pH and buffer.
(18) Cell extracts of Methanobacterium thermoautotrophicum possess a methenyl-tetrahydromethanopterin (methenyl-H4MPT) cyclohydrolase.
(19) In eukaryotes, this enzyme is trifunctional and contains the activities of 10-formyl-H4folate synthetase, 5,10-methenyl-H4folate cyclohydrolase, and 5,10-methylene-H4folate dehydrogenase.
(20) The compounds tested served as substrates for the enzymatic synthesis of methenyl-H4MPT+.