Bioenergetics
Michael H. Stone, Timothy J. Suchomel, W. Guy Hornsby, John P. Wagle, Aaron J. Cunanan in Strength and Conditioning in Sports, 2023
From a biological standpoint, energy is the ability or capacity to perform work. Energy can be conceptualized as either potential (stored) or kinetic (performing work). Various forms of energy exist; for example, elastic, nuclear, electromagnetic, mechanical, and chemical. Biochemical processes form the basis of metabolism and metabolic energy transformations are necessary for all activities accomplished by living systems. Indeed, the concepts of specificity of exercise and training depend to a great extent upon understanding underlying aspects of metabolism, energy use, and generation. Background knowledge of how energy is created for different types of exercises, and how specific types of training can modify energy production, can lead to more efficient and efficacious designs for training programs. Thus, a thorough understanding of bioenergetics and metabolism is necessary for sport scientists and coaches alike.
Natural Preservatives
Philip A. Geis in Cosmetic Microbiology, 2020
Enzymes are most often thought of as key components for enabling rapid and selective reactions needed for cell metabolism, energy generation, and reproduction. However, they can also play a key role in organism defense. While a number of hydrolytic (e.g., lysozyme, subtilisins) and oxidative (e.g., superoxide dismutase) enzymes have been shown to elicit antimicrobial activity either by direct enzymatic effect or through the products of their enzymatic reaction, relatively few enzymes systems have been commercialized for use in consumer products. Although they can be highly effective, their cost is relatively high and product/process must be tailored to maintain enzyme activity. In addition, their potential to elicit allergic reactions must be vetted as part of their application. To date, the cosmetic industry’s primary focus for enzymatic-based preservation has been on the lactoperoxidase/glucose oxidase system.
Role of Nutraceuticals in Risk of Miscarriage and Related Outcomes
Priyanka Bhatt, Maryam Sadat Miraghajani, Sarvadaman Pathak, Yashwant Pathak in Nutraceuticals for Prenatal, Maternal and Offspring’s Nutritional Health, 2019
Bioavailability is the percentage of nutrients ingested and absorbed in the body that can be further used for metabolic processes. The bioavailability of antioxidative nutraceuticals is impacted by many factors, including geometric isomers, matrices around compounds, processing methodology, and nutraceutical type. Most of these factors are directly dependent on the metabolic processes in the body. When food is processed, the bioavailability is often reduced. For example, freshly picked oranges and tomatoes have a higher bioavailability than orange juice or cooked tomatoes. This is because the heat breaks down the carotenoid protein complexes of the nutraceuticals and changes the double bond structure from cis to trans which lowers bioavailability [11] (Figures 6.1 and 6.2). Chemical structures of flavonoids [11].General structure of flavonoids [11].
Migraine as an inflammatory disorder with microglial activation as a prime candidate
Published in Neurological Research, 2023
Amrit Sudershan, Mohd Younis, Srishty Sudershan, Parvinder Kumar
P2Y12R is a P2Y metabotropic ‘G-protein-coupled purinergic receptor’ that belongs to the P2 receptors family and is restrictively expressed on microglia in the CNS [89]. Their role is implicated in the release of pro-inflammatory cytokines by the response to infections, injury, and immunologic challenges [91]. Due to repeated CSD attacks, the neuronal population is significantly damaged which raises the possibility of ATP release. Adenosine 5’-triphosphate (ATP) plays multifaceted roles in energy metabolism, biosynthesis, and intracellular signal transduction including in the activation of purinergic receptors. These extracellular nucleotides and receptor interactions lead to microglial activation thereby facilitating their motility and chemotaxis. Activation of P2Y12R also leads to the increased release of proinflammatory cytokines, NO products, and superoxides formation [92]. P2Y12 is necessary for neuron–microglia interactions and have a significant impact on neuropathic pain which involved pain-related postsynaptic enhancement via microglia activation.
Evaluation of the antimicrobial mechanism of biogenic selenium nanoparticles against Pseudomonas fluorescens
Published in Biofouling, 2023
Ying Xu, Ting Zhang, Jiarui Che, Jiajia Yi, Lina Wei, Hongliang Li
ATP is an important energy molecule for all living organisms and it plays a vital role in a variety of physiological processes such as respiration, metabolism, and enzymatic reactions (Li et al. 2016). Under normal circumstances, intracellular ATP levels remain in a stable state. However, the disruption of cell homeostasis and integrity may cause changes in intracellular ATP concentrations. Compared with the control group, it was found that the intracellular ATP concentrations decreased significantly after treatment with SeNPs (p < 0.05), and the extracellular ATP concentrations showed an increasing trend, among which 2 × MIC of SeNPs led to the greatest depletion (Figure 6). This depletion of cellular ATP indicated an impaired energy metabolic pathway, which in turn might impede ATP synthesis. On the other hand, SeNPs increased the cell membrane permeability, resulting in leakage of intracellular protons, so that the inside and outside of the cell membrane formed a proton gradient difference. According to the chemiosmosis theory, this gradient difference is the electromotive potential of the proton. The leakage of the proton hindered the synthesis of ATP, leading to the reduction of the intracellular ATP content (Jung et al. 2015).
Subcutaneous catabolism of peptide therapeutics: bioanalytical approaches and ADME considerations
Published in Xenobiotica, 2022
Simone Esposito, Laura Orsatti, Vincenzo Pucci
The most relevant biotransformation occurring at the SC injection site is the cleavage of peptide bonds by means of proteases or peptidases, which generates smaller peptides or amino acids. This type of biotransformation is referred to as catabolism, in contrast to the term metabolism used for biotransformation mainly observed in small molecules. Proteolytic enzymes are broadly divided into two categories: exopeptidases, which catalyse the cleavage at the N-terminal or C-terminal removing a single amino acid, and endopeptidases, which cleave peptide bonds within the sequence (López-Otín and Bond 2008). Exopeptidases are intuitively divided into aminopeptidases and carboxypeptidases, while endopeptidases are traditionally classified on the basis of their catalytic site as cysteine peptidases (e.g. dipeptidyl peptidase IV), aspartic peptidases (e.g. pepsin), serine peptidases (e.g. cathepsin B), and metallopeptidases (e.g. matrix metalloprotease 2 and 9) (de Veer et al. 2014a).