BIO1541 (ENGLISH TRANSLATION) - La bioénergétique et la metabolisme

Synthetic work

Changes in chemical bonds to build new molecules, such as protein synthesis.

Mechanical work

Physical changes in the position or orientation of a cell or cellular structure.

Concentration work

Movement of molecules or ions across a membrane against a concentration gradient.

Electrical work

Movement of ions across a membrane resulting in an electrical and concentration gradient.

Heat production

Release of heat energy as a byproduct of metabolic reactions.

Bioluminescence

The production and emission of light by a living organism.

Phototrophs

Organisms that capture light energy from the sun and convert it into chemical energy.

Chemotrophs

Organisms that obtain energy by oxidizing organic or inorganic chemical compounds.

Metabolism

The sum total of all chemical reactions occurring within a living organism to maintain life.

Metabolic pathways

Series of sequential enzymatic reactions that synthesize or break down complex molecules.

Anabolic pathways

Metabolic pathways that consume energy to build complex molecules from simpler ones.

Catabolic pathways

Metabolic pathways that release energy by breaking down complex molecules into simpler ones.

Kinetic energy

The energy associated with the motion of objects or molecules.

Thermal energy

Kinetic energy associated with the random movement of atoms or molecules (heat).

Potential energy

Stored energy that matter possesses because of its location, structure, or spatial arrangement.

Chemical energy

Potential energy available for release in a chemical reaction.

Isolated system

A system that cannot exchange matter or energy with its surroundings.

Open system

A system that can exchange both energy and matter with its surroundings.

First law of thermodynamics

Principle of conservation of energy; energy can be transformed from one form to another, but it cannot be created or destroyed.

Second law of thermodynamics

Principle stating that every energy transfer or transformation increases the entropy (disorder) of the universe.

Entropy

A quantitative measure of randomness, disorder, or randomness in a system.

Spontaneous reaction

A chemical or physical process that occurs naturally without requiring an input of external energy (ΔG < 0).

Non-spontaneous reaction

A process that requires an input of free energy to occur (ΔG > 0).

Free energy (G)

The portion of a system's energy that can perform work when temperature and pressure are uniform throughout the system.

Gibbs free energy change (ΔG)

The change in free energy during a process; determines whether a reaction is spontaneous or non-spontaneous.

Exergonic reaction

A spontaneous chemical reaction that proceeds with a net release of free energy (ΔG < 0).

Endergonic reaction

A non-spontaneous chemical reaction that absorbs free energy from its surroundings (ΔG > 0).

Energy coupling

The use of an exergonic process to drive an endergonic process.

ATP (Adenosine Triphosphate)

The primary energy currency of the cell, composed of ribose, adenine, and three phosphate groups.

ATP hydrolysis

The exergonic cleavage of ATP into ADP and inorganic phosphate (Pi), releasing energy for cellular work.

Activation energy (Ea)

The initial amount of energy required to contort reactant molecules so bonds can break and start a chemical reaction.

Transition state

An unstable, high-energy intermediate state reached during a chemical reaction before products are formed.

Enzymes

Biological catalysts (usually proteins) that speed up metabolic reactions by lowering the activation energy barrier.

Feedback inhibition

A metabolic control mechanism in which the end product of a pathway inhibits an enzyme early in that pathway to prevent overproduction.

Feedback activation

A metabolic control mechanism where a product or intermediate increases the activity of an enzyme in the pathway to accelerate production.