Concept 7.1: Catabolic pathways yield energy by oxidizing organic fuels

What are catabolic pathways?

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

What is the function of exergonic reactions?

They occur at constant temperature without the input of electrical or photon energy.

What role do enzymes play in catabolic pathways?

Enzymes start the breakdown of organic compounds into simpler waste products, releasing usable energy.

What is aerobic respiration?

The most efficient catabolic pathway that uses oxygen to break down organic fuel, producing energy.

What is the overall equation for aerobic respiration?

Organic compounds + O2 → CO2 + H2O + Energy.

What is the free-energy change of the breakdown of glucose?

-686 kcal/mol (ΔG = -686 kcal/mol), indicating a spontaneous reaction.

What is fermentation?

A catabolic process that partially degrades sugars without oxygen.

What is the definition of cellular respiration?

Includes both aerobic and anaerobic processes, typically referring to aerobic respiration.

What are redox reactions?

Chemical reactions that involve the transfer of electrons between reactants.

What does oxidation and reduction mean in redox reactions?

Oxidation is the loss of electrons, and reduction is the gain of electrons.

What is the role of NAD+ in cellular respiration?

Acts as an electron carrier, cycling between its oxidized form and reduced form.

What is the electron transport chain?

A series of molecules, mainly proteins, in the inner mitochondrial membrane that transfer electrons, leading to ATP production.

What are the three main stages of cellular respiration?

Glycolysis, pyruvate oxidation and citric acid cycle, oxidative phosphorylation.

Where does glycolysis occur?

In the cytoplasm.

What is oxidative phosphorylation?

The process that occurs in the electron transport chain and chemiosmosis, producing the majority of ATP.

What is substrate-level phosphorylation?

Direct transfer of a phosphate group from an organic substrate to ADP to form ATP.

How can cellular respiration produce up to 32 ATP molecules?

By converting the energy stored in glucose into a usable form for cellular activities.