Energy Metabolism Regulation and Creatine Chemistry

Creatine phosphate, also known as PCr, is a high-energy molecule found in skeletal muscle and brain. It acts as a readily available energy reserve, quickly converting ADP to ATP, the main energy currency of the cell.

Creatine phosphate is synthesized from the amino acids arginine and glycine, with the addition of a methyl group from methionine.

Creatine kinase is an enzyme that catalyzes the conversion of creatine to creatine phosphate, and vice versa. This reversible reaction allows for the rapid regeneration of ATP.

Creatine phosphate is broken down into creatinine, which is then excreted in urine. This occurs naturally and can be measured to assess kidney function.

Creatine phosphate is particularly important during short bursts of high-intensity activity as it provides a rapid source of energy for muscle contraction.

Creatine phosphate is used intravenously in hospitals for certain cardiovascular problems and is also used by some athletes to enhance performance.

A high-energy compound found in muscle and brain that acts as a short-term energy reserve.

An enzyme that catalyzes the reversible phosphorylation of creatine, creating phosphocreatine.

A specific type of creatine kinase found in muscles and brain that is released into the blood upon tissue damage.

The waste product of creatine phosphate metabolism, excreted through urine.

The process of filtering blood in the kidneys, mainly via glomeruli, to remove waste products like creatinine.

The process of reabsorbing useful molecules from the filtered fluid back into the blood, which rarely happens for creatinine.

Elevated creatinine levels in the blood, often indicating kidney malfunctions.

The process of synthesizing creatine from glycocyamine, mainly in the liver.

Glycogen is a large, branched polymer of glucose stored in the liver and muscles. It is a non-osmotic molecule, meaning it doesn't disrupt the osmotic pressure of the cell.

Insulin is a hormone secreted by the pancreas that helps lower blood glucose levels. It stimulates glycogen synthase, an enzyme that adds glucose molecules to glycogen chains.

Glucagon is a hormone secreted by the pancreas that raises blood glucose levels. It stimulates glycogenolysis, the breakdown of glycogen into glucose.

When blood sugar levels are high, the liver takes in more glucose than it releases, storing it as glycogen.

After a meal, the liver releases stored glucose from glycogen to maintain blood sugar levels.

Muscle cells store glycogen as an immediate energy source for muscle contraction. However, they cannot release this glucose into the bloodstream.

The breakdown of glycogen into glucose is called glycogenolysis.

The production of glucose from non-carbohydrate sources, like amino acids, is called gluconeogenesis. This process can be stimulated by glucagon.

Creatinine clearance (CrCl) is a test that measures how well your kidneys filter waste from your blood. It is a measure of glomerular filtration rate (GFR), which is the rate at which waste products are filtered from the blood by the kidneys.

Glomerular filtration rate (GFR) is a measure of how well your kidneys are filtering waste from your blood. A normal GFR is 90-120 mL/min/1.73 m2, meaning your kidneys are functioning well. A GFR below 60 mL/min/1.73 m2 indicates kidney disease.

A high creatinine level may indicate kidney problems or other issues. However, high creatinine could also be due to increased muscle mass or a high protein diet.

Glycogen is made up of many glucose molecules linked together in a branched chain. The glucose molecules are linked together by α(1→4) glycosidic bonds for linear chains and α(1→6) glycosidic bonds for branches.

Glycogen is important for regulating blood sugar levels and providing energy to the body. When blood sugar levels drop, the body breaks down glycogen to release glucose into the blood.

Glycogen metabolism refers to the processes involved in the synthesis and breakdown of glycogen. Glycogen is synthesized (made) when blood sugar levels are high and broken down when blood sugar levels are low.

The breakdown of glycogen into glucose 1-phosphate, the remodeling of the glycogen substrate for further decomposition, and the conversion of glucose 1-phosphate to glucose 6-phosphate for further metabolic processes.

The process by which glucose 6-phosphate, derived from glycogen breakdown, is utilized for energy production through glycolysis, used in the pentose phosphate pathway for NADPH and ribose synthesis, or converted into free glucose for release into the bloodstream.

A type of metabolic pathway that generates NADPH, a reducing agent essential for various cellular processes, and ribose, a key component of nucleic acids.

The synthesis of glycogen from glucose, a process that requires a specific activated form of glucose called UDP-glucose.

A regulatory mechanism in glycogen metabolism where enzymes respond to changes in metabolite concentrations, allowing the cell to adapt to its energy needs.

A regulatory mechanism in glycogen metabolism involving phosphorylation of enzymes by hormones, altering their activity to meet the demands of the entire organism.

The coordinated control of both glycogen synthesis and degradation, ensuring the body's energy needs are met in a balanced manner.

A molecule that plays a vital role in glycogen synthesis, formed by the reaction of UTP and glucose 1-phosphate. It is responsible for adding glucose units to the growing glycogen molecule.