TCA cycle


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cycle

 [si´k'l]
a succession or recurring series of events.
cardiac cycle a complete cardiac movement, or heart beat, including systole, diastole, and the intervening pause.
Cardiac cycle. From Applegate, 2000.
cell cycle the cycle of biochemical and morphological events occurring in a reproducing cell population; it consists of the S phase, occurring toward the end of interphase, in which DNA is synthesized; the G2 phase, a relatively quiescent period; the M phase, consisting of the four phases of mitosis; and the G1 phase of interphase, which lasts until the S phase of the next cycle.
citric acid cycle tricarboxylic acid cycle.
estrous cycle the recurring periods of estrus in adult females of most mammalian species and the correlated changes in the reproductive tract from one period to another.
hair cycle the successive phases of the production and then loss of hair, consisting of anagen, catagen, and telogen.
menstrual cycle see menstrual cycle.
ovarian cycle the sequence of physiologic changes in the ovary involved in ovulation; see also ovulation and reproduction.
reproductive cycle the cycle of physiologic changes in the reproductive organs, from the time of fertilization of the ovum through gestation and childbirth; see also reproduction.
sex cycle (sexual cycle)
1. the physiologic changes that recur regularly in the reproductive organs of nonpregnant female mammals.
2. the period of sexual reproduction in an organism that also reproduces asexually.
tricarboxylic acid cycle the cyclic metabolic mechanism by which the complete oxidation of the acetyl portion of acetyl-coenzyme A is effected; the process is the chief source of mammalian energy, during which carbon chains of sugars, fatty acids, and amino acids are metabolized to yield carbon dioxide, water, and high-energy phosphate bonds. Called also citric acid cycle, Krebs cycle, and TCA cycle.
 Central pathways of metabolism: How the body produces energy from the energy-containing nutrients using the tricarboxylic acid cycle. From Davis and Sherer, 1994.
urea cycle a cyclic series of reactions that produce urea; it is a major route for removal of the ammonia produced in the metabolism of amino acids in the liver and kidney.

TCA cycle

Abbreviation for tricarboxylic acid cycle.

TCA cycle (Tricarboxylic Acid Cycle)

see KREBS CYCLE.

TCA cycle

tricarboxylic acid cycle.
References in periodicals archive ?
III] -mediated disruption of the hepatic TCA cycle leads to a loss of normal acetyl-CoA flux that results in a push towards ketogenesis, as shown in the plasma metabolomic findings and in the increased expression of FFA synthesis--and [beta]-oxidation-related genes (Table 2 and Figure 5).
Evidence for metabolic dysfunction includes altered metabolites of glycolysis as well as a disruption of the TCA cycle due in part to decreased IDH enzymatic activity.
Sadly, the conclusion that cyanobacteria have an incomplete TCA cycle is written into many textbooks as fact, simply because the research teams in 1967 misinterpreted their failure to find a particular enzyme," Bryant said.
The products of glycolysis (pyruvate and malate) can be completely oxidized in the TCA cycle with production of ATP and reduced nucleotides.
Figure 1 shows the pathways for a reductive autotroph in which the five starting points generated in the reductive TCA cycle lead stepwise to the canonical 20 amino acids and 4 ribonucleotides.
It has purposely and deliberately deactivated the major source of energy (ATP production by the TCA cycle) and has relied only on the glycolytic pathway, turning off the TCA cycle.
The authors propose that deregulation of the TCA cycle and disrupted electron transport provide building blocks that lead to cell proliferation at the expense of nutrient production.
2007); among these, the reductive TCA cycle (rTCA) is the pathway utilized by many reductive chemoautotrophs (Fuchs, 1989; Nakagawa and Takai, 2008).
Smith and Morowitz (2004) and Wachtershauser (1990) theorize that the reductive TCA cycle operated in primitive autotrophs.
Pyruvate formed in these reactions can then be oxidized (via the TCA cycle and the electron transport chain) to generate more ATP, or it can be used as a building block in a variety of biosynthesis, including the production of natural products.