Chemicals of Life – Carbohydrates & Related Concepts

Twenty vocabulary flashcards covering key terms from the lecture on carbohydrates, polymer chemistry, and related biological molecules.

Biomolecule

Any organic molecule (e.g., carbohydrate, lipid, protein, nucleic acid) essential to structure and function of living organisms.

Polymer

A long macromolecule made of many similar or identical repeating units (monomers) linked by covalent bonds.

Monomer

A small molecular subunit that can join with others to form a polymer.

Condensation (Dehydration) Reaction

Enzyme-catalyzed process that joins two monomers by removing an –OH from one and an –H from the other, releasing H₂O.

Hydrolysis

Reaction that splits a polymer into monomers by adding a molecule of water, attaching –OH and –H to the exposed sites.

Carbohydrate

Organic compound with the formula (CH₂O)ₙ; usually sweet, water-soluble saccharides that store energy or provide structural support.

Monosaccharide

Simplest carbohydrate (3–7 carbons); basic sugar unit that can exist in linear or ring form and serve as building block for larger sugars.

Disaccharide

Sugar formed when two monosaccharides are covalently linked by a glycosidic bond (e.g., maltose, lactose, sucrose).

Polysaccharide

Polymer of hundreds to thousands of monosaccharides; functions in energy storage (starch, glycogen) or structural support (cellulose, chitin).

Glycosidic Bond

Covalent linkage between two monosaccharides created during a condensation reaction.

Anomeric Carbon

The carbonyl-derived carbon in a sugar ring that bears a free –OH; it is more reactive and responsible for reducing properties.

Reducing Sugar

Sugar capable of reducing Cu²⁺ to Cu⁺ (Benedict/Fehling test) because it has a free anomeric –OH group.

Starch

Plant storage polysaccharide made entirely of α-glucose units; stored in plastids and turns blue-black with iodine.

Amylose

Linear, unbranched helical component of starch composed of α-1,4-linked glucose units.

Amylopectin

Branched component of starch with an α-1,4 backbone and α-1,6 branch points.

Glycogen

Highly branched α-glucose polymer that serves as the main storage polysaccharide in animal liver and muscle.

Cellulose

Structural polysaccharide of plant cell walls; unbranched chains of β-1,4-linked β-glucose that assemble into microfibrils.

Chitin

Polymer of amino sugars forming the exoskeleton of arthropods and the cell walls of many fungi.

α-Glucose

Anomer of glucose in which the –OH on the anomeric carbon is oriented below the ring plane; building block of starch and glycogen.

β-Glucose

Anomer of glucose in which the –OH on the anomeric carbon is oriented above the ring plane; building block of cellulose.