Chapter 3: The Chemical Building Blocks of Life (Carbohydrates & Nucleic Acids)

Vocabulary flashcards covering the major concepts and terms from the lecture notes on carbohydrates, nucleic acids, isomers, and related biomolecules.

Macromolecule

A large molecule built from repeating subunits (monomers); includes carbohydrates, proteins, lipids, and nucleic acids.

Monomer

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

Polymer

A large molecule made up of many monomer units linked together.

Dehydration synthesis

Bond formation between monomers with the removal of water; builds polymers.

Hydrolysis

Bond breaking of polymers by adding water; polymers split into monomers.

Functional group

A specific group of atoms that imparts characteristic chemical properties to a molecule.

Hydroxyl group

-OH; a polar functional group found in alcohols and sugars.

Carboxyl group

-COOH; acidic group found in amino acids and fatty acids.

Phosphate group

-O-P-O-…; present in nucleotides and ATP; involved in energy transfer.

Amino group

-NH2; basic group found in amino acids.

Sulfhydryl group

-SH; enables disulfide bond formation in proteins (e.g., cysteine).

Methyl group

-CH3; nonpolar group affecting molecule properties.

Monosaccharide

A simple sugar; basic unit of carbohydrates (e.g., glucose, fructose, galactose).

Disaccharide

Two monosaccharides linked by dehydration synthesis (e.g., sucrose, lactose, maltose).

Polysaccharide

Long chains of monosaccharides; energy storage or structural support (e.g., starch, glycogen, cellulose, chitin).

Glycosidic bond

Bond between sugar units formed during dehydration synthesis.

Isomer

Molecules with the same formula but different structures or arrangements.

Structural isomer

Isomers that differ in the actual carbon skeleton arrangement.

Stereoisomer

Isomers that differ in spatial arrangement of atoms around a carbon.

Glucose

A six-carbon monosaccharide (C6H12O6); key energy source; an aldose sugar.

Fructose

A six-carbon monosaccharide; structural isomer of glucose (a ketose).

Galactose

A six-carbon monosaccharide; stereoisomer of glucose.

Nucleotide

Monomer of nucleic acids; sugar (deoxyribose or ribose) + phosphate + nitrogenous base.

Nucleic acid

Polymer of nucleotides (DNA and RNA) that store and express genetic information.

DNA

Deoxyribonucleic acid; stores genetic information; double helix; uses deoxyribose sugar and A-T, C-G base pairing.

RNA

Ribonucleic acid; usually single-stranded; uses ribose sugar and A-U, C-G base pairing.

Purine

A group of nitrogenous bases (adenine and guanine) with two rings.

Pyrimidine

A group of nitrogenous bases (cytosine, thymine, uracil) with one ring.

Adenine

Purine base that pairs with thymine (DNA) or uracil (RNA).

Thymine

Pyrimidine base that pairs with adenine in DNA.

Cytosine

Pyrimidine base that pairs with guanine.

Guanine

Purine base that pairs with cytosine.

Uracil

Pyrimidine base that pairs with adenine in RNA (replaces thymine).

Phosphodiester bond

Bond linking nucleotides in DNA/RNA; forms the sugar–phosphate backbone.

ATP

Adenosine triphosphate; primary energy currency of the cell.

NAD+

Nicotinamide adenine dinucleotide; electron carrier in metabolism.

FAD

Flavin adenine dinucleotide; electron carrier in metabolism.

Starch

Polysaccharide in plants; energy storage.

Glycogen

Polysaccharide in animals; rapid energy storage.

Cellulose

Polysaccharide in plants; structural component of plant cell walls.

Chitin

Polysaccharide; structural support in arthropods and fungi.

Deoxyribose

Five-carbon sugar in DNA; lacks 2'-OH group.

Ribose

Five-carbon sugar in RNA; contains 2'-OH groups.

Base pairing rules

In DNA: A pairs with T, C with G (in RNA, A with U replaces T).