Carbon and the Molecular Diversity of Life Flashcards

Vocabulary flashcards reviewing core terminology, functional groups, chemical reactions, carbohydrates, and lipids from Chapter 3: Carbon and the Molecular Diversity of Life.

Structural Isomers

Molecules that have the same molecular formula but differ in the covalent arrangement or branching of their atoms.

Cis-Trans Isomers

Molecules that have the same covalent bonds but differ in their spatial arrangement around a double bond.

Enantiomers

Molecules that are mirror-image isomers of each other, which are important in pharmacology.

Dehydration Reaction

A chemical reaction that joins two monomers together into a polymer by releasing a water molecule ($\text{monomer} + \text{monomer} \rightarrow \text{polymer} + \text{H}_2\text{O}$).

Hydrolysis Reaction

A chemical reaction that breaks the bond between monomers in a polymer by adding a water molecule ($\text{polymer} + \text{H}_2\text{O} \rightarrow \text{monomer} + \text{monomer}$).

Polymer Hydrolysis Rule

The mathematical relationship stating that completely hydrolyzing a polymer chain of $n$ monomers requires $(n - 1)$ water molecules.

Monosaccharide

A single sugar unit (e.g., glucose) that serves as the monomer building block for carbohydrates.

Disaccharide

A carbohydrate consisting of two monosaccharides joined by a glycosidic linkage (e.g., lactose = glucose + galactose).

Polysaccharide

A carbohydrate polymer composed of many monosaccharides joined together by glycosidic linkages (e.g., starch, glycogen, cellulose).

Starch

A plant storage polysaccharide made of glucose monomers joined by $\alpha$ glycosidic linkages that is lightly branched or unbranched and digestible by humans.

Glycogen

A highly branched animal storage polysaccharide made of glucose monomers joined by $\alpha$ glycosidic linkages, stored mainly in liver and muscle cells.

Cellulose

An unbranched structural polysaccharide found in plant cell walls made of glucose monomers joined by $\beta$ glycosidic linkages, which humans cannot digest.

Saturated Fatty Acid

A fatty acid chain with no double bonds between carbon atoms and maximum hydrogen content, resulting in a solid state at room temperature; commonly found in animal fats.

Unsaturated Fatty Acid

A fatty acid chain with one or more double bonds between carbon atoms and fewer hydrogen atoms, resulting in a liquid state at room temperature; commonly found in plant oils.

Phospholipid

An amphipathic lipid consisting of a glycerol bonded to two fatty acid tails and a phosphate head, which spontaneously forms cell membrane bilayers.

Amphipathic

Describing a molecule that contains both a hydrophobic (water-fearing) region and a hydrophilic (water-loving) region.

Steroid

A type of lipid characterized by a carbon skeleton with four fused rings (e.g., estrogen, testosterone), classified as a lipid because it is made mostly of nonpolar C--C and C--H bonds.