Succinic acidSuccinic acid (səkˈsɪnᵻk) is a dicarboxylic acid with the chemical formula (CH2)2(CO2H)2. In living organisms, succinic acid takes the form of an anion, succinate, which has multiple biological roles as a metabolic intermediate being converted into fumarate by the enzyme succinate dehydrogenase in complex 2 of the electron transport chain which is involved in making ATP, and as a signaling molecule reflecting the cellular metabolic state. Succinate is generated in mitochondria via the tricarboxylic acid cycle (TCA).
Cardiac muscleCardiac muscle (also called heart muscle or myocardium) is one of three types of vertebrate muscle tissues, with the other two being skeletal muscle and smooth muscle. It is an involuntary, striated muscle that constitutes the main tissue of the wall of the heart. The cardiac muscle (myocardium) forms a thick middle layer between the outer layer of the heart wall (the pericardium) and the inner layer (the endocardium), with blood supplied via the coronary circulation.
Pyruvate dehydrogenase complexPyruvate dehydrogenase complex (PDC) is a complex of three enzymes that converts pyruvate into acetyl-CoA by a process called pyruvate decarboxylation. Acetyl-CoA may then be used in the citric acid cycle to carry out cellular respiration, and this complex links the glycolysis metabolic pathway to the citric acid cycle. Pyruvate decarboxylation is also known as the "pyruvate dehydrogenase reaction" because it also involves the oxidation of pyruvate.
G alpha subunitG alpha subunits are one of the three types of subunit of guanine nucleotide binding proteins, which are membrane-associated, heterotrimeric G proteins. G proteins and their receptors (GPCRs) form one of the most prevalent signaling systems in mammalian cells, regulating systems as diverse as sensory perception, cell growth and hormonal regulation. At the cell surface, the binding of ligands such as hormones and neurotransmitters to a GPCR activates the receptor by causing a conformational change, which in turn activates the bound G protein on the intracellular-side of the membrane.
Active transportIn cellular biology, active transport is the movement of molecules or ions across a cell membrane from a region of lower concentration to a region of higher concentration—against the concentration gradient. Active transport requires cellular energy to achieve this movement. There are two types of active transport: primary active transport that uses adenosine triphosphate (ATP), and secondary active transport that uses an electrochemical gradient.
Transforming growth factor betaTransforming growth factor beta (TGF-β) is a multifunctional cytokine belonging to the transforming growth factor superfamily that includes three different mammalian isoforms (TGF-β 1 to 3, HGNC symbols TGFB1, TGFB2, TGFB3) and many other signaling proteins. TGFB proteins are produced by all white blood cell lineages. Activated TGF-β complexes with other factors to form a serine/threonine kinase complex that binds to TGF-β receptors. TGF-β receptors are composed of both type 1 and type 2 receptor subunits.
HomeostasisIn biology, homeostasis (British also homoeostasis) (/hɒmɪə(ʊ)ˈsteɪsɪs/) is the state of steady internal, physical, chemical, and social conditions maintained by living systems. This is the condition of optimal functioning for the organism and includes many variables, such as body temperature and fluid balance, being kept within certain pre-set limits (homeostatic range). Other variables include the pH of extracellular fluid, the concentrations of sodium, potassium, and calcium ions, as well as the blood sugar level, and these need to be regulated despite changes in the environment, diet, or level of activity.
Glucose 6-phosphateGlucose 6-phosphate (G6P, sometimes called the Robison ester) is a glucose sugar phosphorylated at the hydroxy group on carbon 6. This dianion is very common in cells as the majority of glucose entering a cell will become phosphorylated in this way. Because of its prominent position in cellular chemistry, glucose 6-phosphate has many possible fates within the cell. It lies at the start of two major metabolic pathways: glycolysis and the pentose phosphate pathway.
Cell potencyCell potency is a cell's ability to differentiate into other cell types. The more cell types a cell can differentiate into, the greater its potency. Potency is also described as the gene activation potential within a cell, which like a continuum, begins with totipotency to designate a cell with the most differentiation potential, pluripotency, multipotency, oligopotency, and finally unipotency. Totipotency (Lat. totipotentia, "ability for all [things]") is the ability of a single cell to divide and produce all of the differentiated cells in an organism.
Energy homeostasisIn biology, energy homeostasis, or the homeostatic control of energy balance, is a biological process that involves the coordinated homeostatic regulation of food intake (energy inflow) and energy expenditure (energy outflow). The human brain, particularly the hypothalamus, plays a central role in regulating energy homeostasis and generating the sense of hunger by integrating a number of biochemical signals that transmit information about energy balance. Fifty percent of the energy from glucose metabolism is immediately converted to heat.
