Metabolism and Cellular Energy Production

Vocabulary-style flashcards covering the fundamentals of metabolism, including ATP production, aerobic and anaerobic pathways, and ketosis.

Metabolism

The sum of all chemical reactions in the body that transform metabolites through enzyme-controlled pathways.

Metabolites

Chemicals that are processed step-by-step in metabolic pathways.

Metabolic maps

Diagrams showing the complex pathways of thousands of metabolic reactions.

Anabolism

The process of building molecules, tissues, and energy reserves like fat.

Catabolism

The process of breaking down molecules to produce energy ($ATP$).

Burning (in chemistry)

A reaction with oxygen that releases energy; carbon becomes $CO_2$ and hydrogen becomes $H_2O$.

ATP

Adenosine triphosphate; the cell's main energy molecule consisting of adenine, ribose, and three phosphate groups.

Glycolysis

An anaerobic process in the cytoplasm that breaks down glucose into pyruvate, with a net gain of $2\,ATP$.

Krebs cycle

Also known as the citric acid cycle or TCA cycle; an aerobic pathway in the mitochondria that uses Acetyl-CoA to produce energy.

Acetyl-CoA

A molecule carried by Coenzyme A that connects glycolysis to the Krebs cycle and is a product of beta oxidation.

Beta oxidation

The aerobic breakdown of fatty acids into two-carbon units (Acetyl-CoA) within the mitochondria.

Deamination

The removal of an amino group from an amino acid, resulting in the waste product urea and a carbon skeleton used for energy.

Electron Transport Chain (ETC)

The final and most productive stage of aerobic energy production, located in the inner mitochondrial membrane.

ATP synthase

The enzyme in the ETC that produced $ATP$ powered by the flow of hydrogen ions ($H^+$) down their concentration gradient.

Oxygen (in metabolism)

The final electron acceptor in the electron transport chain that forms water ($H_2O$) upon accepting electrons.

Ketosis

A metabolic state in which ketone bodies become a major fuel source, often caused by carbohydrate restriction or starvation.

Acetoacetate

The first ketone body formed when excess Acetyl-CoA accumulates because the Krebs cycle cannot process it fast enough.

Ketone bodies

Alternative fuel sources (including acetoacetate, acetone, and $\beta\text{-hydroxybutyrate}$) produced from fat breakdown during starvation or carbohydrate restriction.