Insulin acts as a key regulator of glucose metabolism by promoting glucose uptake by cells, inhibiting glucose production by the liver, and facilitating the storage of glucose as glycogen.

Glucagon is the primary hormone that counteracts the effects of insulin during fasting. It stimulates the liver to produce glucose through glycogenolysis and gluconeogenesis, thereby maintaining blood glucose levels.

The electron transport chain is a series of protein complexes located in the inner mitochondrial membrane. Its primary function is to generate ATP through oxidative phosphorylation, which involves the transfer of electrons from NADH and FADH2 to oxygen, resulting in the production of water.

Glycolysis is the metabolic pathway that occurs in the cytoplasm of cells and involves the breakdown of glucose into pyruvate. It is the first step in the process of cellular respiration.

The Krebs cycle, also known as the citric acid cycle or tricarboxylic acid cycle, is a series of chemical reactions that occur in the mitochondria of cells. Its primary function is to completely oxidize acetyl-CoA derived from glucose, producing NADH and FADH2, which are used in the electron transport chain to generate ATP.

Epinephrine, also known as adrenaline, is a hormone that plays a key role in the regulation of lipolysis in adipose tissue. It stimulates the breakdown of triglycerides into glycerol and fatty acids, releasing them into the bloodstream for energy production.

Glycogen is a complex carbohydrate stored in the liver and muscles. Its primary function is to serve as a storage form of glucose for energy production. Additionally, glycogen plays a crucial role in regulating blood glucose levels by releasing glucose into the bloodstream when needed.

Ketogenesis is the metabolic pathway that occurs in the liver during periods of prolonged fasting or starvation. It involves the breakdown of fatty acids into ketone bodies, which can be used as an alternative fuel source for the brain and other tissues.

Thyroid hormones, including thyroxine (T4) and triiodothyronine (T3), play a crucial role in metabolic regulation. They stimulate the basal metabolic rate, regulate body temperature, and control growth and development.

Parathyroid hormone (PTH) is the primary hormone responsible for regulating calcium and phosphate metabolism. It acts on the bones, kidneys, and intestines to maintain calcium and phosphate homeostasis.

The sodium-potassium pump, also known as the Na+/K+-ATPase, is a membrane protein that plays a crucial role in cellular transport. It actively transports sodium and potassium ions across the cell membrane, maintaining the cell membrane potential, regulating cell volume, and facilitating the transport of other molecules.

Gluconeogenesis is the metabolic pathway that occurs in the liver and kidneys during fasting or starvation. It involves the conversion of non-carbohydrate substrates, such as amino acids and glycerol, into glucose.

The liver plays a central role in metabolic regulation. It stores and releases glucose, detoxifies harmful substances, produces bile for digestion, and performs numerous other metabolic functions.

Leptin is a hormone produced by adipose tissue that plays a crucial role in regulating appetite and satiety. It signals the brain to suppress hunger and increase energy expenditure.

The pancreas is a vital organ involved in metabolic regulation. It produces insulin and glucagon, which regulate blood glucose levels, secretes digestive enzymes for the breakdown of food, and plays a role in maintaining electrolyte balance.