• Study Resource
  • Explore
    • Arts & Humanities
    • Business
    • Engineering & Technology
    • Foreign Language
    • History
    • Math
    • Science
    • Social Science

    Top subcategories

    • Advanced Math
    • Algebra
    • Basic Math
    • Calculus
    • Geometry
    • Linear Algebra
    • Pre-Algebra
    • Pre-Calculus
    • Statistics And Probability
    • Trigonometry
    • other →

    Top subcategories

    • Astronomy
    • Astrophysics
    • Biology
    • Chemistry
    • Earth Science
    • Environmental Science
    • Health Science
    • Physics
    • other →

    Top subcategories

    • Anthropology
    • Law
    • Political Science
    • Psychology
    • Sociology
    • other →

    Top subcategories

    • Accounting
    • Economics
    • Finance
    • Management
    • other →

    Top subcategories

    • Aerospace Engineering
    • Bioengineering
    • Chemical Engineering
    • Civil Engineering
    • Computer Science
    • Electrical Engineering
    • Industrial Engineering
    • Mechanical Engineering
    • Web Design
    • other →

    Top subcategories

    • Architecture
    • Communications
    • English
    • Gender Studies
    • Music
    • Performing Arts
    • Philosophy
    • Religious Studies
    • Writing
    • other →

    Top subcategories

    • Ancient History
    • European History
    • US History
    • World History
    • other →

    Top subcategories

    • Croatian
    • Czech
    • Finnish
    • Greek
    • Hindi
    • Japanese
    • Korean
    • Persian
    • Swedish
    • Turkish
    • other →
 
Profile Documents Logout
Upload
Aging and Speed of Behavior: Possible
Aging and Speed of Behavior: Possible

... MRI study, Rao et al (1989) assessed young and older subjects on a neuropsy­ chological battery that examined a range from motor functioning to intellectual ability. Ten subjects (out of fifty) showed large amounts of LA and had slower simple reaction times than did subjects with little LA. However, ...
Unraveling Biochemical Pathways Affected by Mitochondrial
Unraveling Biochemical Pathways Affected by Mitochondrial

... intestines [37,38]. BCAA degradation is performed by two enzymes: (1) branched-chain amino acid aminotransferase (BCAT) isoenzyme [39] and (2) branched α-keto acid dehydrogenase (BCKD). Two BCAT isoforms resulting from the expression of two different genes comprise the mitochondrial and cytosolic po ...
DANIELE GHEZZI Matr. N°. 708361 Identification and
DANIELE GHEZZI Matr. N°. 708361 Identification and

... units responsible for the transmission of mtDNA characters to the subsequent generation. ...
Answers to the Editor`s and Reviewers` Comments
Answers to the Editor`s and Reviewers` Comments

... in lung of HDM-instilled mice. Numbers of total cells, eosinophils, neutrophils, and lymphocytes in BAL fluids of HDM-instilled mice were increased significantly compared to the numbers of saline-instilled mice administered drug vehicle (SV). The increase in numbers of these cells, especially eosino ...
melatonin and succinate reduce rat liver mitochondrial dysfunction
melatonin and succinate reduce rat liver mitochondrial dysfunction

... considered to play important roles in the pathogenesis of chronic diabetes mellitus and its complications (2, 3). Reactive oxygen species (ROS) may serve as second messengers in the insulin action cascade (redox paradox) (4). Glucose and lipid metabolism are largely dependent on the mitochondrial fu ...
Cu(II)–disulfide complexes display simultaneous superoxide
Cu(II)–disulfide complexes display simultaneous superoxide

... Mitochondrial superoxide production was monitored as the oxidation of the fluorescent probe dihydroethidium, as reported previously [30]. Briefly, rat duodenal epithelium-isolated mitochondria were incubated for 30 min with DHE (10 μM). After incubation, mitochondria were centrifuged for 10 min (14,00 ...
Review: can diet influence the selective advantage of mitochondrial
Review: can diet influence the selective advantage of mitochondrial

... differences in bioenergetics and ATP production have been documented in a wide range of organisms including snakes [13], frogs [14], birds [15], flies [16], mice [17] and humans [18]. This variation can have important evolutionary consequences. Salin et al. [19] suggest that the mitochondrial oxidat ...
In the first part of the general discussion the choice... in this research are discussed.  In the second part... CHAPTER 5
In the first part of the general discussion the choice... in this research are discussed. In the second part... CHAPTER 5

... Phenolic compounds are commonly extracted with organic solvents such as the alcohols methanol and ethanol, acetone, ethyl acetate or their aqueous mixtures (Krygier et al., 1982). Organic solvents have limited use in the food industry and some of these solvents can be toxic to human health such as e ...
Mitochondrial membrane lipid remodeling in
Mitochondrial membrane lipid remodeling in

... membrane lipids Mitochondria are membrane-enclosed cellular structures, which are classically defined as energy-producing organelles, although their influence extends to many other cell functions. In the classic, although controversial at the time, endosymbiotic theory proposed by Lynn Margulis in the ...
Report Organelles in Blastocystis that Blur the
Report Organelles in Blastocystis that Blur the

... Pathways of the iron-sulfur cluster assembly are depicted in brown. Light blue represents the glycine-cleavage-system pathway. The question mark next to propionate shows that propionate production has not been assayed for Blastocystis; propionate is a metabolic end product of succinate degradation. ...
Pulsing of Membrane Potential in Individual
Pulsing of Membrane Potential in Individual

... 1 online). Occurrences of decrease and recovery of membrane potential, which we refer to as pulses, took place within a 5- to 50-s timeframe (typically ;20 s) and involved a variable degree of TMRM loss ranging from ;20% down to background levels of TMRM fluorescence. In an unstimulated cell, there ...
Lipids Simple by Dr Sarma
Lipids Simple by Dr Sarma

... -Superoxide dismutase, catalase, glutathione peroxidase • Scavenging or ‘chain-breaking’ or ‘sacrificial’antioxidants -Vitamins A,C, and E ...
Redox homeostasis in plants under abiotic stress: role of electron
Redox homeostasis in plants under abiotic stress: role of electron

... under optimum conditions, a high GSH:GSSG ratio is maintained (Mhamdi et al., 2010; Noctor et al., 2011). In stressed conditions, GSH along with ascorbate (AsA) plays a central role in scavenging of ROS. Many studies have indicated a correlation between levels of H2 O2 and glutathione (Noctor et al. ...
Eds., M. Kawaguchi, K. Misaki, H. Sato, T. Yokokawa, T.... and S. Tanabe, pp. 35–40.
Eds., M. Kawaguchi, K. Misaki, H. Sato, T. Yokokawa, T.... and S. Tanabe, pp. 35–40.

... Taurine is synthesized either from the oxidation of L-cysteine via cysteine dioxygenase (CDO), which generates cysteine sulfinate that is decarboxylated by cysteinesulfinic acid decarboxylase (CSD). These reactions are essential for the biosynthesis of taurine. It has been postulated that taurine is ...
Full-Text PDF
Full-Text PDF

... confirmed the disruption of the anti-oxidant protection system and increased production of ROS in patients with epilepsy. Animal seizure models have also shown neuroprotective effects following both endogenous and exogenous anti-oxidants [20]. It is known that mitochondrial impairment occurs acutely ...
Role of Krebs Cycle in the Mechanism of Stability Internal Medium
Role of Krebs Cycle in the Mechanism of Stability Internal Medium

... display balance catabolic exergonic processes and anabolic endergonic processes [1,2]. Catabolic anaerobic oxidative phosphorylation of glycolysis exerts the driving mechanism as anabolic endergonic processes as well as catabolic anaerobic exergonic processes via sharing these reverse processes in “ ...
Redox cycling
Redox cycling

...  Redox reactions are reversible and most redox active compounds may have either pro- or antioxidant properties, acting as either “oxidant” or “reductant”, depending upon overall conditions  The redox potential is one determinant for reactions occurring with a redox active compound, but enzyme meta ...
Rapamycin increases mitochondrial efficiency by mtDNA
Rapamycin increases mitochondrial efficiency by mtDNA

... function, and show for the first time that the full effects of these benefits are dependent ...
PDF - Journal of Rare Disorders
PDF - Journal of Rare Disorders

... species  iden fica on  and  forensic  studies.  Because  mtDNA  have  a high  muta on  rate  and  lack  of  repair  mechanisms,  once  a  muta on  occurs  in  mtDNA  it  is  permanent.12  Hence,  we  can  find  many  muta ons,  all  over  the  circular  mtDNA.  Furthermore,  mitochondrial  genes are ...
linolenic acid prevent insulin resistance but have divergent impacts
linolenic acid prevent insulin resistance but have divergent impacts

... Mitochondrial dysfunction is a central hypothesis in the progression of skeletal muscle IR and is characterized traditionally by reduced content or impairment of function affecting rates of FAO (26). However, given that increased mitochondrial content can parallel the development of IR (15, 19, 53) ...
mitochondrial biogenesis during
mitochondrial biogenesis during

... about a twofold increase in mitochondrial RNA and DNA content within the first 3 h of incubation . Nuclear RNA synthesis also seems to increase under these conditions as does protein synthesis on cytoplasmic ribosomes (Clegg and Golub, 1969) . ...
Identification of a molecular component of the mitochondrial
Identification of a molecular component of the mitochondrial

... However, eukaryotic orthologues to Pat have not been identified in either the mitochondrial or nuclear genome [9]. An alternative scenario in eukaryotes could be that mitochondrial proteins are acetylated in the cytosol prior to mitochondrial import. However, as fasting and feeding result in a dynam ...
Sensitivity of plant mitochondrial terminal oxidases to the lipid
Sensitivity of plant mitochondrial terminal oxidases to the lipid

... are highly susceptible to peroxidation by ROS and a self-propagating chain of free radical reactions can produce various aldehydes, alkenals and HAEs (hydroxyalkenals), including MDA (malondialdehyde) and HNE (4-hydroxy-2-nonenal) [3]. These aldehydes are cytotoxic and generally more stable than ROS ...
Skeletal muscle phenotype affects fasting
Skeletal muscle phenotype affects fasting

... which was associated with a reduction of both total muscle and mitochondrial oxidative phosphorylation protein, and with an increase of intramuscular lipid concentration. By contrast, fasting decreased the activity of oxidative phosphorylation but did not alter the coupling efficiency and protein ex ...
Connecting Proline and γ-Aminobutyric Acid in Stressed
Connecting Proline and γ-Aminobutyric Acid in Stressed

... The accumulation of proline (Pro) in plants exposed to biotic/abiotic stress is a well-documented and conserved response in most vegetal species. Stress conditions induce the overproduction of reactive oxygen species which can lead to cellular damage. In vitro assays have shown that enzyme inactivat ...
< 1 2 3 4 5 6 ... 11 >

Free-radical theory of aging



The free radical theory of aging (FRTA) states that organisms age because cells accumulate free radical damage over time. A free radical is any atom or molecule that has a single unpaired electron in an outer shell. While a few free radicals such as melanin are not chemically reactive, most biologically-relevant free radicals are highly reactive. For most biological structures, free radical damage is closely associated with oxidative damage. Antioxidants are reducing agents, and limit oxidative damage to biological structures by passivating them from free radicals.Strictly speaking, the free radical theory is only concerned with free radicals such as superoxide ( O2− ), but it has since been expanded to encompass oxidative damage from other reactive oxygen species such as hydrogen peroxide (H2O2), or peroxynitrite (OONO−).Denham Harman first proposed the free radical theory of aging in the 1950s, and in the 1970s extended the idea to implicate mitochondrial production of reactive oxygen species.In some model organisms, such as yeast and Drosophila, there is evidence that reducing oxidative damage can extend lifespan. In mice, interventions that enhance oxidative damage generally shorten lifespan. However, in roundworms (Caenorhabditis elegans), blocking the production of the naturally occurring antioxidant superoxide dismutase has recently been shown to increase lifespan. Whether reducing oxidative damage below normal levels is sufficient to extend lifespan remains an open and controversial question.
  • studyres.com © 2025
  • DMCA
  • Privacy
  • Terms
  • Report