Energetics

Early metabolic steps, including glycolysis and the activity of the pyruvate dehydrogenase complex, yield a two-carbon fragment called an acetyl group, which is linked to a large cofactor known as coenzyme A (or CoA). It is during the citric acid cycle that acetyl-CoA is oxidized to the waste product, carbon dioxide, along with the reduction of the cofactors NAD+ and ubiquinone

94p zingzing09 21-10-2012 58 9   Download

In the context of this work, simplified models have been developed to describe the thermodynamics of power conversion, the energetics of multi-effect evaporation (MED), and the costs of electricity and heat cogenerated by the dual-purpose power plant.

16p christabelhuynh 30-05-2020 16 2   Download

The phenomenon of the transformation of proteins into amyloid-fibrils is of interest, firstly, because it is closely connected to the so-called conformational diseases, many of which are hitherto incurable, and secondly, because it remains to be explained in physical terms (energetically and structurally). The process leads to fibrous aggregates in the form of extracellular amyloid plaques, neuro-fibrillary tangles and other intracytoplasmic or intranuclear inclusions.

10p research12 01-06-2013 33 4   Download

Corynebacterium ammoniagenesis an overproducer of xanthosine-5¢-monophosphate (XMP) by consuming either glcose (glc) or glutamic acid (glu). Its energymetabolismwas studiedin vivousing 31 P NMR spectroscopy coupled with a circulating fermentation system (CFS). CFS enabled us to validate directly the cellular dependency on carbon sources and changes in biomolecules produced according to altera-tions in the cellular energetic status.

5p fptmusic 16-04-2013 39 3   Download

NA helicases are ubiquitous molecular motor proteins which harness the chemical free energy of ATPhydrolysis to catalyze the unwinding of energetically stable duplex DNA, and thus play important roles in nearly all aspects of nucleic acid metabolism, including replication, repair, recombina-tion, and transcription. They break the hydrogen bonds between the duplex helix and move unidirectionally along the bound strand. All helicases are also translocases and DNA-dependentATPases.Most contain conserved helicase motifs that act as an engine to power DNA unwinding. ...

14p dell39 03-04-2013 38 5   Download

DNA helicases are molecular
motor enzymes that use the energy of NTP hydrolysis to separate transiently energetic-ally stable duplex DNA into single strands. They are there-fore essential in nearly all DNA metabolic transactions. They act as essential molecular tools for the cellular machinery. Since the discovery of the first DNA helicase in Escherichia coliin1976, several havebeen isolated fromboth prokaryotic and eukaryotic systems.

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a-Conotoxins are small peptides from cone snail venoms that function as nicotinic acetylcholine receptor (nAChR)-competitive antagonists differenti-ating between nAChR subtypes. Current understanding about the mechan-ism of these selective interactions is based largely on mutational analyses, which identify amino acids in the toxin and nAChR that determine the energetics of ligand binding.

16p inspiron33 26-03-2013 46 5   Download

Pigments homologous to the green fluorescent protein (GFP) contribute up to 14% of the soluble protein content of many anthozoans. Maintenance of such high tissue levels poses a severe energetic penalty to the animals if protein turnover is fast. To address this as yet unexplored issue, we estab-lished that the irreversible green-to-red conversion of the GFP-like pig-

10p galaxyss3 21-03-2013 42 3   Download

Biological nitrogen fixation is a vital process in the global nitrogen cycle, transforming dinitrogen in the atmosphere into ammonia. Being a very energy-demanding and oxygen-sensitive process, both expression and activity of the nitrogenase enzyme are tightly regu-lated. Rhodospirillum rubrumis a free-living, photosynthetic, purple non-sulfur nitrogen-fixing bacterium, which has been extensively used as a model organism for metabolic and regulatory studies regarding nitrogen fixation.

24p galaxyss3 19-03-2013 66 4   Download

The mechanisms underlying increased cardioprotection in younger female mice are unclear. We hypothesized that serine-threonine protein kinase (protein kinase B; Akt) triggers a metabolic gene switch (decreased fatty acids, increased glucose) in female hearts to enhance mitochondrial bio-energetic capacity, conferring protection against oxidative stress.

7p media19 04-03-2013 22 3   Download

Tyr235 of GTP-dependent phosphoenolpyruvate (PEP) carboxykinase is a fully invariant residue. The aromatic ring of this residue establishes an energetically favorable weak anion–quadrupole interaction with PEP carboxylate. The role of Tyr235 in catalysis was investigated via kinetic analysis of site-directed mutagenesis-derived variants.

10p vinaphone15 28-02-2013 22 2   Download

Tham khảo luận văn - đề án 'báo cáo khoa học: energetic and metabolic transient response of saccharomyces cerevisiae to benzoic acid', luận văn - báo cáo, báo cáo khoa học phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả

15p vinaphone15 28-02-2013 44 3   Download

Saccharomyces cerevisiaeis known to be able to adapt to the presence of the commonly used food preservative benzoic acid with a large energy expenditure. Some mechanisms for the adaptation process have been sug-gested, but its quantitative energetic and metabolic aspects have rarely been discussed.

12p vinaphone15 28-02-2013 35 2   Download

Although allostery plays a central role in driving protein–DNA interac-tions, the physical basis of such cooperative behavior remains poorly understood. In the present study, using isothermal titration calorimetry in conjunction with site-directed mutagenesis, we provide evidence that an intricate network of energetically-coupled residues within the basic regions of the Jun-Fos heterodimeric transcription factor accounts for its allosteric binding to DNA.

15p cosis54 05-01-2013 34 3   Download