Catabolic Pathways and Energy Yield

These flashcards cover key vocabulary and concepts related to catabolic pathways and energy yield from organic fuels, focusing on cellular respiration and redox reactions.

Catabolic pathways

Metabolic pathways that release stored energy by breaking down complex molecules.

Aerobic respiration

A catabolic process where oxygen is consumed along with organic fuel to produce ATP.

Anaerobic respiration

A process that harvests chemical energy without using oxygen.

ATP

Adenosine triphosphate, the primary molecule that drives cellular work.

Glycolysis

The first stage of cellular respiration that breaks down glucose into pyruvate.

Oxidation

The loss of electrons from one substance in a redox reaction.

Reduction

The addition of electrons to another substance in a redox reaction.

Redox reactions

Reactions that involve the transfer of electrons between substances.

NADH

A reduced coenzyme that carries electrons during cellular respiration.

Dehydrogenases

Enzymes that oxidize substrates by removing hydrogen atoms.

Citric acid cycle

A series of reactions that further oxidize acetyl CoA to produce ATP.

Substrate-level phosphorylation

A process of forming ATP by transferring a phosphate group from a substrate.

Oxidative phosphorylation

The synthesis of ATP powered by redox reactions of the electron transport chain.

Electron transport chain

A series of protein complexes that transfer electrons, releasing energy for ATP synthesis.

Glucose

A simple sugar that serves as the primary fuel for cellular respiration.

Fermentation

A partial degradation of sugars that occurs without oxygen.

Potential energy

Energy stored in the arrangement of electrons in chemical bonds.

Heat

Energy that is lost to the environment during metabolic reactions.

Photosynthesis

The process by which plants convert sunlight into chemical energy, producing oxygen.

Exergonic reactions

Reactions that release energy, often associated with the breakdown of complex molecules.

Chemical recycling

The process of reusing chemical elements essential for life in biological systems.

Elecctron carriers

Molecules that transport electrons during cellular respiration.

Acetyl CoA

A key intermediate in the metabolic pathway for the citric acid cycle.

Hydrogen ions (H⁺)

Positively charged ions that are released during redox reactions.

Carbon dioxide (CO₂)

A waste product of aerobic respiration, used in photosynthesis.

Water (H₂O)

A byproduct of cellular respiration formed when oxygen reacts with electrons and protons.

Pyruvate

A three-carbon compound that is the end product of glycolysis.

FAD

A coenzyme that acts as an electron carrier, similar to NADH.

Aerobic

Referring to processes that require oxygen.

Anaerobic

Referring to processes that do not require oxygen.

ATP synthase

An enzyme that synthesizes ATP from ADP and inorganic phosphate.

Metabolic pathways

Sequences of enzymatic reactions that lead to the conversion of substrates into products.

Activation energy

The energy required to initiate a chemical reaction.

Ecosystem

A community of living organisms and their interactions with their environment.

Electron donor

A substance that donates electrons in a redox reaction.

Electron acceptor

A substance that accepts electrons in a redox reaction.

Krebs cycle

Another name for the citric acid cycle, named after Hans Krebs.

Polymers

Large molecules made of many repeated subunits, formed through dehydration reactions.