Energetics of Living Systems and Molecular Biology

These flashcards cover key concepts in energetics, metabolism, photosynthesis, and molecular biology, including essential definitions and mechanisms.

Kinetic Energy

The energy of motion; energy that an object possesses due to its movement.

Potential Energy

Stored energy; energy that an object possesses due to its position or structure.

Oxidation Reaction

A chemical reaction that involves the loss of electrons or an increase in oxidation state.

Reduction Reaction

A chemical reaction that involves the gain of electrons or a decrease in oxidation state.

First Law of Thermodynamics

Energy cannot be created or destroyed, only transformed from one form to another.

Second Law of Thermodynamics

The total entropy of a closed system can never decrease over time; systems tend toward disorder.

Free Energy

The energy available to do work during a chemical reaction; can indicate the spontaneity of a reaction.

Enzyme Catalyst

A protein that speeds up chemical reactions by lowering the activation energy needed.

Competitive Inhibitor

A substance that reduces the activity of an enzyme by binding to the active site, competing with the substrate.

Non-competitive Inhibitor

A substance that reduces enzyme activity by binding to an enzyme at a site other than the active site.

Biochemical Pathway

A series of chemical reactions occurring within a cell, often involving multiple enzymes.

Feedback Inhibition

A regulatory mechanism in which the end product of a pathway inhibits an earlier step to prevent overproduction.

ATP (Adenosine Triphosphate)

A high-energy molecule that provides energy for cellular processes and is involved in energy storage.

Autotrophs

Organisms that produce their own food through photosynthesis or chemosynthesis.

Heterotrophs

Organisms that obtain their energy by consuming organic compounds, such as plants or other animals.

Electron Transport Chain

A series of protein complexes that transfer electrons and produce ATP in cellular respiration.

Chemiosmosis

The process of synthesizing ATP using the energy of an electrochemical gradient created by the electron transport chain.

Glycolysis

The process of breaking down glucose into pyruvate, producing a small amount of ATP.

Krebs Cycle

A series of chemical reactions used by all aerobic organisms to generate energy through the oxidation of acetyl-CoA.

Photosynthesis

The process by which green plants and some other organisms use sunlight to synthesize foods from carbon dioxide and water.

Light-Dependent Reactions

Reactions in photosynthesis that convert light energy into chemical energy, producing ATP and NADPH.

Calvin Cycle

A set of biochemical reactions that take place in the chloroplasts of photosynthetic organisms, fixing carbon dioxide into glucose.

DNA Polymerase

An enzyme responsible for synthesizing new DNA strands by adding nucleotides to a pre-existing chain.

Telomeres

The repetitive sequences at the ends of linear chromosomes that protect them from degradation.

Mutation

A change in the nucleotide sequence of DNA, which can affect gene function and lead to variations in phenotype.