Ch 9 - Metabolism

Nutrition Ch 9

Metabolism

The chemical processes and reactions involved in maintaining life, including energy release and waste excretion.

Anabolic Pathways

Metabolic pathways that use small compounds to build larger ones, requiring energy and more prominent during growth.

Catabolic Pathways

Metabolic pathways that break down compounds, releasing energy, CO2, and H2O, more prominent during weight loss or wasting disease.

ATP (Adenosine Triphosphate)

The energy currency of the cell, used directly for synthesizing compounds, muscle contraction, nerve impulses, and ion pumping.

Oxidation-Reduction Reactions

Key processes in energy metabolism where substances lose or gain electrons or hydrogen, or gain or lose oxygen.

Niacin

Also known as vitamin B-3, a key player in energy metabolism, involved in the formation of NAD+ and NADH.

Riboflavin

Also known as vitamin B-2, a key player in energy metabolism, involved in the formation of FAD and FADH2.

Pantothenic Acid

Also known as vitamin B-5, a precursor to coenzyme A (CoA), important in energy metabolism.

Glycolysis

The metabolic pathway that breaks down glucose into pyruvate, producing ATP and NADH, occurring in the cytosol and does not require oxygen.

Citric Acid Cycle

A series of reactions in which acetyl-CoA is oxidized to produce NADH, FADH2, and GTP, releasing CO2.

Electron Transport Chain

A series of protein complexes that use energy from NADH and FADH2 to produce ATP, with oxygen as the final electron acceptor.

Anaerobic Metabolism

Metabolism that occurs without oxygen, resulting in the conversion of pyruvate to lactate.

Lipolysis

The breakdown of triglycerides into free fatty acids and glycerol for energy production.

Beta-Oxidation

The process of breaking down fatty acids into acetyl-CoA units for entry into the citric acid cycle.

Ketosis

A metabolic state characterized by elevated levels of ketone bodies, often occurring during fasting or low-carbohydrate diets.

Gluconeogenesis

The metabolic process of synthesizing glucose from non-carbohydrate precursors, primarily occurring in the liver.

Inborn Errors of Metabolism

Genetic conditions that affect metabolic pathways, often due to enzyme mutations leading to decreased activity.

Phenylketonuria

A genetic disorder caused by insufficient phenylalanine hydroxylase activity, leading to toxic metabolite accumulation.

Galactosemia

A genetic disorder where the body cannot convert galactose to glucose, requiring dietary restrictions.