Ch. 5 Molecules of Life (Part 1)

Comprehensive vocabulary flashcards covering carbohydrates, monosaccharides, disaccharides, polysaccharides, lipids, fatty acids, phospholipids, and steroids based on Chapter 5 lecture notes.

Biomolecules

The four classes of large biological molecules that make up all living things: carbohydrates, lipids, proteins, and nucleic acids.

Polymer

A large molecule consisting of many similar or identical building blocks (monomers) linked by covalent bonds; carbohydrates, proteins, and nucleic acids are polymers.

Monomer

The broad name for the smallest repeating unit or building block of a compound.

Dehydration Reaction

A chemical reaction that synthesizes a polymer by removing a water molecule to form a new covalent bond between monomers.

Hydrolysis

A chemical reaction that breaks down polymers into monomers by adding a water molecule to break a bond.

Monosaccharide

The simplest carbohydrate or simple sugar that serves as fuel and building material, and acts as the monomer for disaccharides and polysaccharides.

Glucose ($C_6H_{12}O_6$)

The most common monosaccharide and an aldose hexose sugar in the body.

Aldose

A monosaccharide classified by having its carbonyl group located at the end of the carbon skeleton.

Ketose

A monosaccharide classified by having its carbonyl group located in the middle of the carbon skeleton.

Glyceraldehyde

A $3$ carbon triose sugar classified as an aldose.

Dihydroxyacetone

A $3$ carbon triose sugar classified as a ketone.

Ribose

The most common $5$ carbon pentose aldehyde sugar used for DNA and RNA in the body.

Glycosidic Bond

A covalent bond formed between two monosaccharides through a dehydration reaction.

Disaccharide

A sugar formed when a dehydration reaction joins two monosaccharides together with a glycosidic bond.

Maltose

A disaccharide formed by joining two glucose molecules via a dehydration reaction.

Sucrose

A disaccharide formed by joining a glucose molecule and a fructose molecule via a dehydration reaction.

Starch

A plant storage polysaccharide consisting entirely of glucose monomers, occurring as unbranched amylose or somewhat branched amylopectin.

Amylose

The simplest, unbranched form of starch.

Glycogen

An extensively branched storage polysaccharide in animals, stored mainly in liver and muscle cells.

Cellulose

A structural polysaccharide made of glucose monomers linked by $\beta$ glycosidic linkages that forms a major component of plant cell walls.

Alpha ($\nu$) and Beta ($\beta$) Glucose Forms

Two ring forms of glucose based on hydroxyl group orientation; enzymes hydrolyzing $\nu$ linkages in starch cannot hydrolyze $\beta$ linkages in cellulose.

Chitin

A structural polysaccharide composed of N-acetylglucosamine polymers, found in the exoskeletons of arthropods and cell walls of many fungi.

Lipids

A class of biological molecules consisting mostly of hydrocarbons that are hydrophobic and do not form polymers; includes fats, phospholipids, and steroids.

Trigylceride

A fat created by joining three fatty acids to a glycerol molecule via ester linkages; also known as a triglyceride.

Ester Linkage

The covalent bond formed between a hydroxyl group of glycerol and a carboxyl group of a fatty acid in a fat molecule.

Saturated Fatty Acid

A fatty acid with no double bonds and the maximum number of hydrogen atoms, which has fewer kinks, packs tightly, and remains solid at room temperature.

Unsaturated Fatty Acid

A fatty acid containing one or more double bonds, creating kinks in the chain that take up more space and make it liquid at room temperature.

Hydrogenation

The process of adding hydrogen atoms to convert unsaturated fatty acids to saturated fatty acids, which creates unsaturated fats with trans double bonds.

Phospholipid

A lipid composed of two fatty acid hydrophobic tails and a hydrophilic phosphate head attached to a glycerol molecule.

Phospholipid Bilayer

A double-layered arrangement formed when phospholipids self-assemble with hydrophobic tails pointing inward, serving as the main component of cell membranes.

Steroid

A class of lipids characterized by a carbon skeleton consisting of $4$ fixed fused rings.

Cholesterol

An important steroid that acts as a structural component in animal cell membranes.