Cell Bio - Chapter 13: Cellular Energy and Metabolism

Vocabulary flashcards for cell energy and metabolism (from textbook).

Cell Respiration

The process whereby cells harvest useful energy from the chemical-bond energy locked in sugars as the sugar molecule is broken down and oxidized to carbon dioxide (CO2) and water (H2O).

ATP and NADH

Activated carriers that capture the energy released during cell respiration in the form of “high-energy” chemical bonds; serve as portable sources of the chemical groups and electrons needed for biosynthesis.

Catabolism

The breakdown process in which enzymes degrade complex organic molecules into simpler ones.

Glycolysis

A chain of reactions that splits each molecule of glucose into two smaller molecules of pyruvate; takes place in the cytosol and generates ATP and NADH.

Citric Acid Cycle

A series of reactions in which the acetyl group in acetyl CoA is oxidized to CO2 with the production of large amounts of NADH; takes place in mitochondria.

Oxidative Phosphorylation

A process that produces ATP and consumes molecular oxygen (O2 gas), using the high-energy electrons from NADH passed along an electron-transport chain within the mitochondrial inner membrane.

Substrate-Level Phosphorylation

A form of ATP synthesis that takes place in steps 7 and 10 in glycolysis, occurring by the transfer of a phosphate group directly from a substrate molecule to ADP.

Fermentation

Energy-yielding pathways that break down sugar in the absence of oxygen, regenerating NAD+ from NADH to maintain glycolysis.

Gluconeogenesis

The process of synthesizing glucose from pyruvate, effectively a reversal of glycolysis.

Glycogen

A branched polymer of glucose used as a food reserve in animal cells, stored as small granules in the cytoplasm, mainly in liver and muscle cells.

Glycogen Phosphorylase

Enzyme that breaks down glycogen, producing glucose 1-phosphate.

Adipocytes

Specialized fat cells where fat is stored as droplets of water-insoluble triacylglycerols.

Anaerobic Respiration

A process used by many bacteria and archaea to generate ATP in the absence of oxygen, using a molecule other than oxygen as a final electron acceptor.

Pyruvate Dehydrogenase Complex

A giant complex of three enzymes that decarboxylates pyruvate in the mitochondrial matrix, producing CO2, NADH, and acetyl CoA.