Question

Regulating Metabolism

1. Fatty acids are broken down into ____________________, which occurs in the ____________________________.

2. High concentrations of acetyl-coA indicates _______________ __________________.

3. Pyruvate comes from the breakdown of __________________ and _________________ _________________.

Answer 1

1. Fatty acids are carboxylic acids with long aliphatic chain , both saturated and unsaturated. These acids are derivations of triacylglycerols (TAGs) or phospholipids. TAGS are metabolised in intestinal lumen by the action of pancreatic lipases and converted into free fatty acids and glycerol. Free fatty acids then further processed into carbon dioxide and water in mitochondria.

2. Acetyl CoA is the catabolised products of glycolysis and Beta oxidation of fatty acids. It is derived from the metabolism of carbohydrates and fatty acids in cytoplasm and mitochondria respectively. High acetyl CoA levels indicate the condition of ketosis. In case of high levels, 2 acetyl -CoA molecule combine to form acetoacetyl coA and hydroxybutyrates leading to the formation of ketone bodies. These ketone bodies are formed in the blood in case of prolonged starvation, due to low carbohydrate diet and uncontrolled Diabetes mellitus, which further leads to condition known as ketoacidosis.

3. Pyruvate comes from the breakdown of carbohydrates (cytosol) and fatty acids (mitochondria). Pyruvate are also obtained from the amino acids degradation.