Biochemistry Basics: Biomolecules, Metabolism, and Redox Reactions

Comprehensive vocabulary flashcards reviewing fundamental biochemistry concepts, including functional groups, ATP dynamics, thermodynamics, redox principles, electron carriers, and respiration.

Carbohydrates

Biological molecules used for energy and structure, the simplest of which are sugars.

Amino acid

A small molecule that serves as a building block of proteins.

Lipids

A broad group of molecules that do not mix well with water (such as fats and oils), important for energy storage, cell membranes, and hormones/signaling.

Alcohol

A molecule containing a hydroxyl group ($—\text{OH}$) attached to a carbon atom.

Ketone

A molecule containing a carbonyl group ($\text{C=O}$) positioned within its carbon chain.

Methyl group

A small functional group of atoms with the formula $—\text{CH}_3$ that appears in many biological molecules.

Phosphate group

A chemical group ($—\text{PO}_4$) found in ATP, DNA, RNA, phospholipids, and phosphorylated proteins.

Oxidation

The loss of electrons, commonly associated with the loss of hydrogen, gain of oxygen, or an increase in oxidation number.

Reduction

The gain of electrons, commonly associated with the gain of hydrogen, loss of oxygen, or a decrease in oxidation number.

OIL RIG

A mnemonic for redox reactions standing for "Oxidation Is Loss, Reduction Is Gain" (of electrons).

Phosphorylation

The process of adding a phosphate group to a molecule, which can alter its behavior and play a critical role in metabolism and cell signaling.

Hydrolysis

A chemical reaction that breaks down a molecule through the addition of water.

Condensation

A chemical reaction that joins molecules together with the removal of water.

ATP (Adenosine Triphosphate)

The cell's primary immediate energy-transfer molecule, functioning as a rechargeable energy currency rather than a long-term storage reservoir.

Inorganic phosphate ($\text{P}_i$)

The free phosphate group released when ATP is converted to ADP to release usable free energy.

Mitochondria

Cellular organelles that serve as a major site of ATP production, especially in the presence of oxygen.

Exergonic reaction

A chemical reaction that releases usable free energy, such as the breakdown of ATP into ADP and $\text{P}_i$.

Endergonic reaction

A chemical reaction that requires an input of free energy, such as building complex molecules from smaller precursors.

Electron carrier

A molecule that picks up electrons from one metabolic reaction and transports them to another, such as the electron transport chain, to help produce ATP.

$\text{NAD}^+$ (Nicotinamide Adenine Dinucleotide)

The oxidized, "empty" form of NAD that accepts electrons and hydrogen to become NADH.

NADH

The reduced, "loaded" form of Nicotinamide Adenine Dinucleotide carrying high-energy electrons.

FAD (Flavin Adenine Dinucleotide)

The oxidized, "empty" form of FAD that accepts reducing equivalents to become $\text{FADH}_2$.

$$\text{FADH}_2$$

The reduced, "loaded" form of Flavin Adenine Dinucleotide carrying high-energy electrons.

Oxidation number

A numerical value that tracks an atom's electrons; it increases when electrons are lost and decreases when electrons are gained.

Breathing

The physical process of taking in oxygen ($\text{O}_2$) and releasing carbon dioxide ($\text{CO}_2$).

Cellular respiration

The chemical process taking place inside cells that extracts energy from nutrients.