Fundamental Concepts of Energy and Thermodynamics

These flashcards cover key concepts in energy and thermodynamics, enzymes, metabolism, and biochemical reactions.

What is the definition of energy?

Energy is defined as the capacity to do work.

What does the First Law of Thermodynamics state?

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

What is an example of the Second Law of Thermodynamics?

During cellular respiration, not all energy is harnessed and some is lost as heat, increasing entropy.

What is free energy?

Free energy is the amount of energy available to do work in a system.

What characterizes exergonic reactions?

Exergonic reactions have a negative delta G (ΔG < 0) and are spontaneous.

What characterizes endergonic reactions?

Endergonic reactions have a positive delta G (ΔG > 0) and are nonspontaneous.

What is activation energy?

Activation energy is the initial energy needed to get a reaction going.

What role do enzymes play in biochemical reactions?

Enzymes are biological catalysts that speed up reactions by lowering the activation energy.

What is induced fit in enzyme-catalyzed reactions?

Induced fit is the shape change in an enzyme to more tightly hold the substrates after the enzyme-substrate complex forms.

How can temperature affect enzyme activity?

While raising temperature typically speeds up reactions, exceeding optimal temperature can cause enzyme denaturation.

What are competitive inhibitors?

Competitive inhibitors bind to the active site of an enzyme, competing with the substrate for access.

What are noncompetitive inhibitors?

Noncompetitive inhibitors bind to an allosteric site, altering the enzyme's shape without competing with the substrate.

What is metabolism?

Metabolism encompasses all chemical reactions in living organisms, divided into anabolic and catabolic pathways.

What is a metabolic pathway?

A series of chemical reactions where the product of one reaction becomes the substrate for the next.

What is ATP and its significance in metabolism?

ATP is the primary energy currency of cells, storing energy released during hydrolysis for cellular processes.

What are redox reactions?

Redox reactions involve the transfer of electrons between molecules, crucial for energy production.

What does OILRIG stand for?

Oxidation Is Loss of electrons, Reduction Is Gain of electrons.

What role does NAD+ play in metabolism?

NAD+ serves as an electron acceptor and is reduced to NADH, acting as a high-energy carrier.

Why are fat molecules significant for energy storage?

Fat molecules are a significant energy storage form due to their high bond content; breaking these bonds releases energy.