Magnesium and cell energetics in plants under anoxia

2011 ◽  
Vol 437 (3) ◽  
pp. 373-379 ◽  
Author(s):  
Abir U. Igamberdiev ◽  
Leszek A. Kleczkowski
Keyword(s):  
Energy Efficient ◽  
Alternative Energy ◽  
Active Form ◽  
Stress Conditions ◽  
Signalling Pathways ◽  
Concomitant Increase ◽  
Pyruvate Phosphate Dikinase ◽  
Calcium Dependent ◽  
Alternative Energy Source ◽  
Apparent Equilibrium

Stress conditions (e.g. anoxia) frequently result in a decrease of [ATP] and in an increase of [ADP] and [AMP], with a concomitant increase of [Mg2+] and other cations, e.g. Ca2+. The elevation of [Mg2+] is linked to the shift in the apparent equilibrium of adenylate kinase. As a result, enzymes that use Mg2+ as a cofactor are activated, Ca2+ activates calcium-dependent signalling pathways, and PPi can serve as an alternative energy source in its active form of MgPPi or Mg2PPi. Under anoxic conditions in plants, an important source of PPi may come as a result of combined reactions of PK (pyruvate kinase) and PPDK (pyruvate, phosphate dikinase). The PPi formed in the PPDK/PK cycle ignites glycolysis in conditions of low [ATP] by involving PPi-dependent reactions. This saves ATP and makes metabolism under stress conditions more energy efficient.

Pyrophosphate as an alternative energy currency in plants

2021 ◽  
Vol 478 (8) ◽  
pp. 1515-1524
Author(s):  
Abir U. Igamberdiev ◽  
Leszek A. Kleczkowski
Keyword(s):  
Metabolic Pathways ◽  
Energy Efficient ◽  
Alternative Energy ◽  
Plant Cells ◽  
Atp Synthesis ◽  
Continuous Operation ◽  
Low Oxygen ◽  
Pyruvate Phosphate Dikinase ◽  
Oxygen Stress ◽  
Membrane Bound

In the conditions of [Mg2+] elevation that occur, in particular, under low oxygen stress and are the consequence of the decrease in [ATP] and increase in [ADP] and [AMP], pyrophosphate (PPi) can function as an alternative energy currency in plant cells. In addition to its production by various metabolic pathways, PPi can be synthesized in the combined reactions of pyruvate, phosphate dikinase (PPDK) and pyruvate kinase (PK) by so-called PK/PPDK substrate cycle, and in the reverse reaction of membrane-bound H+-pyrophosphatase, which uses the energy of electrochemical gradients generated on tonoplast and plasma membrane. The PPi can then be consumed in its active forms of MgPPi and Mg2PPi by PPi-utilizing enzymes, which require an elevated [Mg2+]. This ensures a continuous operation of glycolysis in the conditions of suppressed ATP synthesis, keeping metabolism energy efficient and less dependent on ATP.

(Re)examining the Citicorp Case: ethical paragon or chimera?

2002 ◽  
Vol 6 (3) ◽  
pp. 269-276 ◽  
Author(s):  
Eugene Kremer
Keyword(s):  
Energy Source ◽  
Energy Efficient ◽  
Alternative Energy ◽  
Floor Area ◽  
Alternative Energy Source

The 59-story, nearly 1.6 million gross square foot, Citicorp Center tower completed during 1977 in mid-town Manhattan was designed by the much-celebrated architect Hugh Stubbins of Cambridge, Massachusetts. The tower incorporated an array of notable technological features including doubledecker elevator cabs to reduce the number of elevator shafts and thereby increase the usable floor area, alternative energy source and reclamation systems, and low-brightness lighting that helped render the tower some 42% more energy efficient than comparable structures designed to conventional standards (http://www.loringengineers).

Alternative Energy Source for Heating System of Woodworking Enterprise

2018 ◽  
Vol 4 (1) ◽  
pp. 27-30 ◽  
Author(s):  
Olena Savchenko ◽  
◽  
Vasyl Zhelykh ◽  
Yurii Yurkevych ◽  
Khrystyna Kozak ◽  
...  
Keyword(s):  
Energy Source ◽  
Alternative Energy ◽  
Heating System ◽  
Alternative Energy Source

scholarly journals Decentral Energy Generation Potential of Anaerobic Digestion of Black Water and Kitchen Refuse for Eco-District Planning

Energies ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2948
Author(s):  
Soufia Mohammadi ◽  
Pilar Monsalvete Álvarez de Uribarri ◽  
Ursula Eicker
Keyword(s):  
Experimental Data ◽  
Anaerobic Digestion ◽  
Energy Demand ◽  
Alternative Energy ◽  
Organic Substrate ◽  
Mass Balances ◽  
Waste Streams ◽  
Black Water ◽  
Alternative Energy Source ◽  
Simulation Based

Biogas technology is an important alternative energy source worldwide. Blackwater and kitchen refuse represent ideal waste streams for bioenergy recovery through anaerobic co-digestion. Modeling of the biokinetics of anaerobic digestion on several aspects, such as microbial activity, substrate degradation, and methane production, from co-digestion of black water (BW) and kitchen refuse (KR) was the objective of this research. A mathematical model was developed towards a simulation based on mass balances on biomass, the organic substrate, and biogas. The model was implemented in INSEL and experimental data from the literature were used for model validation. The study shows that the simulation results fit well with the experimental data. The energy consumption and generation potential of anaerobic co-digestion of BW and KR were calculated to investigate if the produced biogas could supply the digester’s energy demand. This study can be used to pre-design anaerobic digestion systems in eco-districts.

scholarly journals Use of Human Step Energy as an Alternative Energy Source

2020 ◽  
Vol 3 (3) ◽  
pp. 26-29
Author(s):  
Kateryna Viktorivna Miroshnyk ◽  
Oleh Mykolaiovych Bevza
Keyword(s):  
Energy Source ◽  
Alternative Energy ◽  
Alternative Energy Source
Sign in / Sign up

Export Citation Format

Share Document