Chapter 7 Biochemistry and Organic Molecules - Vocabulary Flashcards

25 vocabulary flashcards covering key terms from the lecture notes on organic molecules, carbohydrates, lipids, proteins, and methods to identify microorganisms.

Miller-Urey experiment

An experiment that simulated early Earth’s atmosphere with water, methane, hydrogen, and ammonia; sparked to mimic lightning and produced amino acids, supporting the primordial soup idea.

primordial soup

A hypothesis that life began in a water body where atmospheric gases combined with energy to form organic carbon compounds.

amino acids

Organic molecules with an amino group, a carboxyl group, a central (alpha) carbon, and a variable side chain (R); building blocks of proteins linked by peptide bonds.

functional groups

Specific atom groups within molecules that determine chemical properties and reactions (e.g., hydroxyl, carbonyl, carboxyl, amino, phosphate, sulfhydryl).

dehydration synthesis

A chemical reaction where monomers join to form polymers with the release of a water molecule.

monomer

A small building block that can join with others to form polymers.

polymer

A large molecule made by linking many monomers through covalent bonds.

carbohydrate

Biomolecule class composed mainly of carbon, hydrogen, and oxygen; energy storage and structural roles; often follow CH2O formula.

monosaccharide

Simple sugar; the building block of carbohydrates; classified by number of carbons (trioses, tetroses, pentoses, hexoses).

disaccharide

Two monosaccharides linked by a glycosidic bond (e.g., maltose, lactose, sucrose).

polysaccharide

Large polymers of monosaccharides; examples include starch, glycogen, and cellulose; not sweet and often not soluble.

glycosidic bond

Covalent bond linking two sugar molecules via hydroxyl groups.

ring structure

Cyclic form of monosaccharides (often with 4+ carbons) formed by a reaction between a carbonyl group and a distant hydroxyl group.

structural isomer

Molecules with the same molecular formula but different bonding sequences.

stereoisomer

Isomers with the same formula and bonding arrangement but different spatial arrangement; includes enantiomers.

enantiomer

A non-superimposable mirror-image stereoisomer exhibiting chirality; often has different biological activity.

optical isomer

Another term for enantiomer; they rotate plane-polarized light, designated as D (+) or L (-).

carbon skeleton

The backbone of carbon atoms in an organic molecule; can be straight, branched, or cyclic.

macromolecule

Very large polymer built from many monomers; four major types: carbohydrates, lipids, proteins, nucleic acids.

triglyceride

Glycerol bound to three fatty acids; nonpolar and energy-dense; major form of stored fat.

phospholipid

Lipid with two fatty acids and a phosphate-containing head; amphipathic and forms cellular membranes.

amphipathic

Molecule having both hydrophilic (polar) and hydrophobic (nonpolar) regions.

lipid bilayer

Two-layer sheet of phospholipids forming the core structure of cellular membranes; hydrophilic heads outward, tails inward.

protein

Polymer of amino acids; performs functions such as catalysis, transport, structure, and signaling; organized into primary–quaternary structures.

peptide bond

Covalent bond between the carboxyl group of one amino acid and the amino group of another, formed by dehydration synthesis.