5-2-_Energetics_and_Redox_reactions

Metabolic Requirements for Life

Liquid water, Nutrients (sources of carbon, nitrogen, etc), a source of energy, and a source of electrons for biochemical reactions.

Autotrophs

Organisms that use CO2 (inorganic carbon) to build cell materials; primary producers essential for synthesizing organic molecules.

Heterotrophs

Organisms that obtain carbon from organic compounds; nearly all chemoorganotrophs.

ATP (Adenosine Triphosphate)

The main energy currency of the cell that powers various cellular functions.

Catabolism

Reactions that obtain energy and break down complex molecules.

Anabolism

Reactions that use energy to synthesize cellular material.

Redox Reactions

Chemical reactions that involve the transfer of electrons, consisting of reduction and oxidation processes.

Reducing Agent

A reactant that donates electrons in a redox reaction, gets oxidized, and often loses H atoms and/or gains O atoms.

Oxidizing Agent

A reactant that accepts electrons in a redox reaction, gets reduced, and gains electrons.

NAD+/NADH

Soluble electron carriers used to shuttle electrons around the cell; NAD+ is the oxidizing agent and NADH is the reducing agent.

Gibbs Free Energy (ΔG)

The actual free energy of a reaction taking conditions into account, affected by temperature and concentrations of substrates and products.

Standard Gibbs Free Energy (ΔG°')

The free energy change of a reaction under standard conditions, calculated based on the nature of reactants/products.

Redox Tower

A representation of various redox couples that indicates their capacity to act as electron donors or acceptors based on their reduction potentials.

Electron Carrier Function

Electron carriers like NADH are enzymatic cofactors that allow electrons to be transferred between reactions.

LEO the lion says GER

Mnemonic to remember that 'Lose Electrons = Oxidized' and 'Gain Electrons = Reduced'.