AP Biology Study Guide: Water, Isomers, and Carbohydrates

Vocabulary flashcards generated from the AP Biology study guide covering water properties, isomers, carbohydrate structure, and metabolic reactions.

High Specific Heat of Water

The property of water requiring a large amount of heat energy to disrupt hydrogen bonds before increasing temperature, allowing organisms and aquatic environments to maintain stable temperatures.

Cohesion

The intermolecular attraction between molecules of the same substance, such as water molecules forming hydrogen bonds with one another.

Surface Tension

A property of water resulting from cohesive hydrogen bonding at the liquid surface, allowing organisms like water striders to move across water without sinking.

Structural Isomers

Molecules that share the same molecular formula but differ in the covalent connectivity of their atoms.

Geometric Isomers

Stereoisomers that have the same molecular formula and covalent connectivity, but differ in the spatial arrangement of atoms around a restricted bond, such as a carbon-carbon double bond.

Enantiomers

Stereoisomers that have the same molecular formula and covalent connectivity, but are nonsuperimposable mirror images of each other.

Chiral Center

A carbon atom bonded to four different groups, creating asymmetry that allows a molecule to exist as a pair of nonsuperimposable mirror-image enantiomers.

Monosaccharide

The simplest type of carbohydrate consisting of a single sugar unit, such as glucose, fructose, or galactose.

Disaccharide

A carbohydrate composed of two monosaccharides joined together by a covalent glycosidic bond, such as sucrose, lactose, or maltose.

Polysaccharide

A carbohydrate polymer consisting of many monosaccharide units joined together by glycosidic bonds, such as starch, glycogen, or cellulose.

Dehydration Synthesis

A reaction process that builds larger molecules from smaller units by forming covalent bonds and releasing a molecule of $H_2O$ for each bond formed.

Hydrolysis

A chemical process that breaks covalent bonds within polymers to separate them into smaller units by using a molecule of $H_2O$.

Starch

A polysaccharide composed of glucose units used primarily by plants for energy storage.

Glycogen

A polysaccharide composed of glucose units used by animals (stored in the liver and skeletal muscles) and fungi for energy storage.

Cellulose

A structural polysaccharide made of glucose units that forms strong fibers providing rigidity and support to plant cell walls.

Maltose Hydrolysis Reaction

A reaction where the addition of a water molecule ($H_2O$) cleaves the covalent glycosidic bond holding maltose together, producing two individual glucose monosaccharides.

Carbohydrate Classifications

A classification system categorizing carbohydrates by sugar unit count: monosaccharides (one sugar unit, e.g., glucose), disaccharides (two joined units, e.g., sucrose), and polysaccharides (many joined units, e.g., starch).

Dehydration Synthesis vs. Hydrolysis

A comparison showing that dehydration synthesis builds polymers, joins units, removes water, and forms covalent bonds, whereas hydrolysis breaks polymers, separates units, uses water, and breaks covalent bonds.