BIOL 120- Chapter 6 - Energy, Metabolism, and Enzymes

What is bioenergetics?

The study of energy conversion in cells, including photosynthesis and cellular respiration.

What is energy?

The capacity to do work or produce heat, existing in various forms such as heat, light, electric, chemical, and nuclear.

What is kinetic energy?

The energy of motion; energy that is actively doing work.

What is potential energy?

Stored energy that has the capacity to perform work.

What is chemical energy?

Energy stored in chemical bonds, released during chemical reactions.

What does the First Law of Thermodynamics state?

Total energy in the universe remains constant; it can be transformed but not created or destroyed.

What does the Second Law of Thermodynamics state?

Energy transformations increase the entropy (disorder) of the universe.

What is metabolism?

The sum of all chemical activities within a living cell.

What are metabolic pathways?

Sequences of enzyme-catalyzed reactions in metabolism.

What is anabolism?

The metabolic pathways that synthesize complex molecules from simpler substrates.

What is catabolism?

The metabolic pathways that break down larger molecules into smaller ones.

What is Gibbs free energy (G)?

The amount of a system's energy that can perform work at constant temperature and pressure.

What is a spontaneous reaction?

A chemical reaction that proceeds on its own without outside influence.

What is an exergonic reaction?

A spontaneous chemical reaction that releases energy.

What is an endergonic reaction?

A chemical reaction that requires energy input to proceed.

What is energy coupling?

The use of energy released from exergonic reactions to drive essential endergonic functions.

What is activation energy (EA)?

The amount of energy that reactants must absorb before a chemical reaction can start.

What is the role of enzymes?

To lower the activation energy of specific biochemical reactions, allowing them to occur more quickly.

What is an enzyme?

A protein that serves as a biological catalyst, lowering the activation energy of reactions.

What is a substrate?

The specific reactant that an enzyme acts upon.

What is a cofactor?

Inorganic ions that bind to certain enzymes and are necessary for their activity.

What is a coenzyme?

Small carbon-containing molecules that are not permanently bound to enzymes and assist in catalysis.

What is a prosthetic group?

Distinctive molecular groups that are permanently bound to their enzyme.

What is ATP?

Adenosine triphosphate, the energy currency of the cell.

What happens during ATP hydrolysis?

ATP is broken down into ADP and inorganic phosphate, releasing energy for cellular processes.

What is phosphorylation?

The transfer of a phosphate group from ATP to another molecule, energizing that molecule.

What is chemiosmosis?

The process by which ATP is synthesized during the transfer of electrons down an electron transport chain.

What are redox reactions?

Chemical reactions that involve the transfer of electrons, where one substance is oxidized and another is reduced.

What is NAD+?

Nicotinamide adenine dinucleotide, an electron carrier involved in redox reactions.

What is FAD?

Flavin adenine dinucleotide, another important electron carrier in cellular respiration.

What are electron carriers?

Small organic molecules that shuttle electrons during redox reactions.