Chapter 3: Carbon and the Molecular Diversity of Life

Vocabulary practice flashcards covering carbon chemistry, functional groups, monomers, polymers, carbohydrates, lipids, proteins, and nucleic acids based on the Chapter 3 Reading Guide.

Macromolecule

Huge molecules formed by the joining of smaller molecules, usually by dehydration synthesis.

Hydrocarbon

Hydrophobic organic molecules consisting of only carbon and hydrogen, such as ethane, propane, petroleum, gasoline, fats, butane, and benzene.

Functional Group

Chemical groups that affect molecular function by being directly involved in chemical reactions.

Carbon Atom Electron Distribution

Atomic structure of carbon showing 6 total electrons, with 4 valence electrons in its outer shell capable of forming 4 covalent bonds with other elements.

Monomer

Repeating units that serve as the building blocks of polymers.

Polymer

Long molecules consisting of many similar or identical building blocks linked together by covalent bonds.

Dehydration Synthesis

Reaction in which two molecules are covalently bonded to each other with the loss of a water molecule.

Hydrolysis

Reaction that converts polymers into monomers by adding water to break covalent bonds.

Isomers

Compounds that have the same molecular formulas but different structural formulas.

Glycosidic Linkage

Covalent bond formed between two monosaccharides.

Storage Polysaccharide

A category of polysaccharides used to store energy, such as starch in plants and glycogen in vertebrates.

Structural Polysaccharide

A category of polysaccharides used for structural support, such as cellulose in plant cell walls and chitin in arthropod exoskeletons.

Ester Linkage

Bond formed between a hydroxyl group and a carboxyl group.

Trans Fat

Unsaturated fats with trans double bonds that may contribute to heart disease.

Carbonyl Group

A functional group consisting of a carbon atom double-bonded to an oxygen atom ($\text{-C=O}$).

Carboxyl Group

A functional group consisting of a carbon atom double-bonded to an oxygen atom and single-bonded to a hydroxyl group ($\text{-COOH}$).

Amino Group

A functional group consisting of a nitrogen atom bonded to two hydrogen atoms ($\text{-NH}_2$).

Phosphate Group

A functional group consisting of a phosphorus atom bonded to four oxygen atoms ($\text{-OPO}_3^{2-}$).

Methyl Group

A functional group consisting of a carbon atom bonded to three hydrogen atoms ($\text{-CH}_3$).

Phospholipid Bilayer

Plasma membrane arrangement in which hydrophilic heads face the surrounding water and hydrophobic tails are shielded in the interior.

Amino Acid Structure

Core structure of protein monomers containing a central $\alpha$ carbon bonded to an amino group, a carboxyl group, a hydrogen atom, and a variable side chain ($R$ group).

R Group (Side Chain)

Variable functional group attached to the central $\alpha$ carbon of an amino acid; 20 different types exist.

Peptide Bond

Covalent bond formed between two amino acids.

Polypeptide

Polymer composed of amino acids.

Protein

Biologically functional molecule made of one or more polypeptides coiled into a 3-D structure.

Primary Structure

The precise sequence of amino acids in a protein chain.

Secondary Protein Structure

Level of protein structure resulting from hydrogen bonds between repeating parts of the polypeptide backbone, forming $\alpha$ helices or $\beta$ pleated sheets.

Tertiary Protein Structure

Three-dimensional shape of a protein resulting from interactions among side chains ($R$ groups), such as hydrogen bonds, ionic bonds, hydrophobic interactions, and disulfide bridges.

Quaternary Protein Structure

Overall protein structure formed from the combination of multiple polypeptide chains.

Denaturation

Process in which a protein unravels and loses its native shape/conformation due to changes in pH, salt concentration, temperature, or transfer from a polar to non-polar environment.

Sickle-Cell Disease

Condition caused by a change in primary structure at the 6th amino acid position (Glu to Val), which alters higher-order structures causing hemoglobin to form fibers and deform red blood cells.

Nucleoside

The portion of a nucleotide consisting of a nitrogenous base and a sugar, but lacking a phosphate group.

Nucleotide Structure

Monomer of nucleic acids composed of a 5-carbon pentose sugar, a nitrogenous base, and a phosphate group.

Antiparallel Strands

Arrangement in a DNA double helix where the 5' ends of the two sugar-phosphate backbones run in opposite directions.

Bioinformatics

The use of computer software to analyze large sets of data from DNA and genomes.

Denaturization