AP Bio - U1C3 Vocab

Macromolecules

a giant molecule formed by the joining of smaller molecules, usually by a dehydration reaction. polysaccharides, proteins, and nucleic acids are macromolecules

Polymer

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

Monomers

the subunit that serves as the building block of a polymer

Enzymes

a macromolecule serving as a catalyst, a chemical agent that increases the rate of a reaction without being consumed by the reaction. most enzymes are proteins

Dehydration reaction

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

Hydrolysis

a chemical reaction breaks bonds between two molecules by the addition of water; functions in disassembly of polymers to monomers

Monosaccharides

the simplest carbohydrate, active alone or serving as a monomer for disaccharides and polysaccharides. also known as simple sugars, they have molecular formulas that are generally some multiple of CH2O

Disaccharide

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

Polysaccharides

a polymer of many monosaccharides, formed by dehydration reactions

Starch

a storage polysaccharide in plants, consisting of entirely of glucose monomers joined by a (alpha) glycosidic linkages

Glycogen

an extensively branched glucose storage polysaccharide found in the liver and muscle of animals; the animal equivalent of starch

Cellulose

a structural polysaccharide of plant cell walls, consisting of glucose monomers joined by B (beta) glycosidic linkages

Chitin

a structural polysaccharide, consisting of amino sugar monomers, found in many fungal cell walls and in the exoskeletons of all arthropods

Isomers

one of two or more compounds that have the same numbers of atoms of the same elements but different structures and hence different properties

Glycosidic linkage

a covalent bond formed between two monosaccharides by a dehydration reaction

Denaturization

in proteins, a process in which a protein loses its native shape due to the disruption of weak chemical bonds and interactions, thereby becoming biologically inactive; in DNA the separation of the two strands of the double helix; occurs under extreme (noncellular) conditions of pH, salt concentration, or temperature

Enantiomer

one of two compounds that are mirror images of each other and that different in shape due to the presence of an asymmetric carbon

Lipids

any group of large biological molecules, including fats, phospholipids, and steroids, that mix poorly, if at all, with water

Fatty acid

a carboxylic acid with a long carbon chain; they vary in length and in number and location of double bonds; three fatty acids linked to a glycerol molecule form a fat molecule, also known as a triacylglycerol or triglyceride

Triacylglycerol

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

Saturated fatty acid

a fatty acid in which all carbons in the hydrocarbon tail are connected by single bonds, thus maximizing the number of hydrogen atoms attached to the carbon skeleton

Unsaturated fatty acid

a fatty acid that has one or more double bonds between carbons in the hydrocarbon tail; such reduces the number of hydrogen atoms attached to the cabin skeleton

Phospholipid

a lipid made up of glycerol joined to two fatty acids and a phosphate group; hydrocarbon chains of them act nonpolar (hydrophobic tails) while the rest acts polar (hydrophilic head). they form bilayers that function as biological membranes

Cholesterol

a steroid that forms an essential component of animal cell membranes and acts as a precursor molecule for the synthesis of other biologically important steroids, such as many hormones

Polypeptide

a polymer of many amino acids linked together by peptide bonds

Protein

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

Amino acid

an organic molecule possessing both a carboxyl and an amino group; they serve as monomers of polypeptides

Peptide bond

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

Primary structure

the level of protein structure referring to the specific linear sequence of amino acids

Secondary structure

regions of repetitive coiling or folding of the polypeptide backbone of a protein due to hydrogen bonding between constituents of the backbone (not the side chains)

Tertiary structure

the overall shape of a protein molecule due to interactions of amino acid side chain, including hydrophobic interactions, ionic bonds, hydrogen bonds, and disulfide bridges

A Helix

a coiled region constituting one form of the secondary structure of proteins, arising from a specific pattern of hydrogen bonding between atoms of the polypeptide backbone (not the side chains)

B pleated sheet

one form of the secondary structure of proteins in which the polypeptide chain folds back and forth; two regions of the chain lie parallel to each other and are held together by hydrogen bonds between atoms of the polypeptide backbone (not the side chains)

Quaternary structure

the particular shape of a complex, aggregate protein, defined by the characteristic three-dimensional arrangement of its constituent subunits, each of a polypeptide

Nucleic acid

a polymer (polynucleotide) consisting of many nucleotide monomers; serves as a blueprint for proteins and, through the actions of proteins, for all cellular activities; two types are DNA and RNA

Deoxyribonucleic acid (DNA)

a nucleic acid molecule, usually a double-stranded helix, in which each polynucleotide strand consists of nucleotide monomers with a deoxyribose sugar and the nitrogenous bases adenine (A), cytosine (C), guanine (G), and thymine (T); capable of being replicated and determining the inherited structure of a cell’s proteins

Ribonucleic acid (RNA)

a type of nucleic acid consisting of a polynucleotide made up of nucleotide monomers with a ribose sugar and the nitrogenous bases adenine (A), cytosine (C), guanine (G), and uracil (U); usually single-stranded; functions in protein synthesis, gene regulation, and as the genome of some viruses

Adenosine triphosphate (ATP)

an adenine-containing nucleoside triphosphate that releases free energy when its triphosphate bonds are hydrolyzed; energy used to drive endergonic reactions in cells

Ploynucleotides

a polymer consisting of many nucleotide monomers in a chain; the nucleotides can be DNA or RNA 

Nucleotides

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

Pyrimidine

one of two nitrogenous bases found in nucleotides, characterized by a six-membered ring; cytosine (C), thymine (T), and uracil (U)

Purine

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

Deoxyribose

the sugar component of DNA nucleotides, having one fewer hydroxyl group than ribose, the sugar component of RNA nucleotides

Ribose

the sugar component of RNA nucleotides

Disulfide bridges

a strong covalent bond formed when the sulfur of one cytosine monomer bonds to the sulfur of another cytosine monomer