Unit 1 AP Biology Vocabulary

A comprehensive set of flashcards covering key vocabulary terms from Unit 1 of AP Biology.

Adhesion

Clinging of one substance to another, such as water to plant cell walls, by means of hydrogen bonds.

Amino acid

An organic molecule possessing both a carboxyl and amino group; serve as the monomers of polypeptides.

Antiparallel

Referring to the arrangement of the sugar-phosphate backbones in a DNA double helix, moving in 5'-3' directions.

Carbohydrate

A sugar or one of its dimers or polymers.

Cohesion

The linking together of like molecules, often by hydrogen bonds.

Dehydration reaction

A chemical reaction in which two molecules become covalently bonded to each other with the removal of a water molecule.

Deoxyribonucleic acid

A nucleic acid molecule, usually a double-stranded helix, that consists of nucleotide monomers with a deoxyribose sugar and the bases adenine, cytosine, guanine, and thymine.

Deoxyribose

The sugar component of DNA nucleotides, having one fewer hydroxyl group than ribose.

Disaccharide

A double sugar, consisting of two monosaccharides joined by a glycosidic linkage formed by a dehydration reaction.

Double helix

The form of native DNA, referring to its two adjacent antiparallel polynucleotide strands wound around an imaginary axis into a spiral shape.

Fat

A lipid consisting of three fatty acids linked to one glycerol molecule; also called a triacylglycerol or triglyceride.

Fatty acid

A carboxylic acid with a long carbon chain; varies in length and in the number and location of double bonds.

Glycosidic linkage

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

Hydrocarbon

An organic molecule consisting of only carbon and hydrogen.

Hydrogen bond

A type of weak chemical bond formed when a slightly positive hydrogen atom of a polar covalent bond in one molecule is attracted to a slightly negative atom in another molecule.

Hydrolysis

A chemical reaction that breaks bonds between two molecules by the addition of water, functioning in the disassembly of polymers to monomers.

Lipid

A group of large biological molecules, including fats, phospholipids, and steroids, that mix poorly with water.

Monomer

The subunit that serves as a building block of a polymer.

Monosaccharide

The simplest carbohydrate, active alone or serving as a monomer for disaccharides and polysaccharides.

Nucleic acid

A polymer consisting of many nucleotide monomers; serves as a blueprint for proteins and, through the actions of proteins, for all cellular activities.

Nucleotide

The building block of a nucleic acid, consisting of a five-carbon sugar covalently bonded to a nitrogenous base and one to three phosphate groups.

Peptide bond

The covalent bond between the carboxyl group on one amino acid and the amino group on another, formed by a dehydration reaction.

Phospholipid

A lipid made up of a glycerol joined to two fatty acids and a phosphate group; forms bilayers that function as biological membranes.

Polar molecule

A molecule with an uneven distribution of charges in different regions of the molecule.

Polymer

A long molecule consisting of many similar or identical monomers linked together by covalent bonds.

Polypeptide

A polymer of many amino acids linked together by peptide bonds.

Polysaccharide

A polymer of many monosaccharides, formed by dehydration reactions.

Protein

A biologically functional molecule consisting of one or more polypeptides folded and coiled into a specific three-dimensional structure.

Purine

One of two types of nitrogenous bases found in nucleotides, characterized by a six-membered ring fused to a five-membered ring (adenine and guanine).

Pyrimidine

One of two types of nitrogenous bases found in nucleotides, characterized by a six-membered ring (cytosine, thymine, uracil).

Ribonucleic acid

A type of nucleic acid consisting of a polynucleotide made up of nucleotide monomers with a ribose sugar; usually single-stranded.

Ribose

The sugar component of RNA nucleotides.

Saturated fatty acid

A fatty acid in which all carbons in the hydrocarbon tail are connected by single bonds, maximizing the number of hydrogen atoms attached.

Solute

A substance that is dissolved in a solution.

Solution

A liquid that is a homogeneous mixture of two or more substances.

Solvent

The dissolving agent of a solution.

Surface tension

A measure of how difficult it is to stretch or break the surface of a liquid.

Triglyceride

A lipid consisting of three fatty acids linked to one glycerol molecule; also called a fat.

Unsaturated fatty acid

A fatty acid that has one or more double bonds between carbons in the hydrocarbon tail.

Isomer

A compound with the same numbers and types of atoms but different structures.

Structural isomers

Isomers that differ in the arrangement of atoms.

Cis-trans isomers

Isomers with a different arrangement of atoms due to double bonds.

Enantiomers

Isomers that are 'mirror images' of one another due to one carbon being bonded to four different groups.

Primary protein structure

A protein's sequence of amino acids.

Secondary protein structure

Coiling or folding of a polypeptide due to hydrogen bonding between amino acid backbones.

Tertiary protein structure

Three-dimensional folding pattern of a protein due to side chain interactions (combination of alpha-helices and beta-sheets).

Quaternary protein structure

A protein consisting of more than one polypeptide.