How Cells Obtain Energy

These flashcards cover key concepts related to how cells obtain and utilize energy, including thermodynamics, metabolism, glycolysis, and fermentation processes.

Energy

The capacity to do work and cause change.

Kinetic Energy

Energy of motion, which performs work by transferring motion to other matter.

Potential Energy

Stored energy, exemplified by water behind a dam.

Thermodynamics

The study of energy and energy transfer in physical objects.

Bioenergetics

The study of energy flow (transformation) through living systems.

First Law of Thermodynamics

The total amount of energy in the universe is constant and conserved; energy can be transferred or transformed but cannot be created or destroyed.

Second Law of Thermodynamics

Energy transfer and transformation is not totally efficient; some energy is lost as heat.

Metabolism

The sum of all chemical reactions of a cell or organism.

Autotrophs

Organisms that generate their own chemical energy, e.g., through photosynthesis.

Heterotrophs

Organisms that must obtain chemical energy by ingesting or absorbing other organisms.

ATP

Adenosine triphosphate, the primary energy currency of the cell.

Enzyme

A substance that helps a reaction occur, acting as a catalyst.

Competitive Inhibitors

Substances that compete with the substrate for the active site on an enzyme.

Noncompetitive Inhibitors

Substances that bind to an enzyme at a different location, inhibiting substrate binding.

Endergonic Reactions

Reactions that absorb energy and have products with more free energy than reactants.

Exergonic Reactions

Reactions that release energy; energy is exiting the system.

Glycolysis

The first step of cellular respiration where glucose is broken down into pyruvate.

Citric Acid Cycle

Also known as Krebs cycle, breaks down acetyl CoA and produces energy carriers.

Oxidative Phosphorylation

The final step in cellular respiration that generates ATP using the electron transport chain.

Fermentation

Process that regenerates NAD+ in the absence of oxygen, allowing glycolysis to continue.

Lactic Acid Fermentation

A type of fermentation occurring in animals, producing lactic acid.

Alcohol Fermentation

A type of fermentation occurring in yeast, producing ethanol and CO2.

Triglycerides

Lipids used for long-term energy storage, broken down into fatty acids and glycerol.