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Ap Biology Ch. 5
Macromolecules
Question | Answer |
---|---|
macromolecule | A giant molecule formed by th joining of smaller molecules, usuall by a condensation reaction. Polysaccharides, proteins, and nucleic acids are macromolecules |
polymer | A long molecule consisting of many similar or identical monomers linked together |
monomer | The subunit that serves as the building block of a polymer |
condensation reaction | A reaction in which two molecules become covalently bonded to each other through the loss of a small molecule, usually water; also called a dehydration reaction |
dehydration reaction | A chemical reaction in which two molecules covalently bonded to each other with the removal of a water molecule |
hydrolysis | A chemical process that lyses, or splits, molecules by the addition of water |
carbohydrates | A sugar (monosaccharide) or one of its dimers (disaccharide) or polymers (polysaccharides) |
monosaccharides | The simplest carbohydrate, active alone or serving as a monomer for disaccharides and polysaccharides. Also known as simple sugars, the molecular formulas of monosaccharides are generallyin some multiple of CH₂O |
disaccharide | A double sugar, consisting of two monosaccharides joined by dehydration synthesis |
glycosidic linkage | A covalent bond formed between two monosaccharides by a dehydration reaction |
polysaccharides | A polymer of up to over a thousand monosaccharides, formed by dehydration reactions |
starch | A storage polysaccharide in plants consisting entirely of glucose |
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 cell walls, consisting of glucose monomers joined by β- 1, 4 glycosidic linkages |
chitin | A structural polysaccharide od an amino sugar found in many fungi and in the exoskeletons of all arthropods |
fat (triacylglycerol) | A biological compound consisting of three fatty acids linked to on glycerol molecule |
fatty acid | A long carbon chain caarboxylic acid. Fatty acuds vary in length and in the number and location of double bonds; three fatty acids linked to a glycerol molecule form a fat |
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 atims that can attach to the carbon skeleton |
unsaturated fatty acid | A fatty acid possessing one or more double bonds between the carbons in the hydrocarbon tail. Such bonding reduces the number of hydrogen atims attached to the carbon skeleton |
phospholipid | A molecule that is a consituent of the inner bilayer of biological membranes, having a polar, hydrophilic head and a nonpolar, hydrophobic tail |
steroid | A type of lipid characterized by a carbon skeleton consisting of four rings with various functional groups attached |
cholesterol | A steriod that forms an essential component of animal cell membranes and acts as a precursor molecule for the synthesis od other biologically important steriods |
enzyme | A protein serving as a catalyst, a chemical agent that changes the rate of a reaction without being consumed by the reaction |
catalyst | A chemical agent that changes the rate of a reaction without being consumed by the reaction |
polypeptide | A polymer (chain) of many amino acids linked together by peptide bonds |
protein | A three-dimensional biological polymer constructed from a set of 20 different monomers called amino acids |
amino acid | An organic molecule possessing both carboxyl and amino groups. Amino acids serve as the monomers of proteins |
peptide bond | The covalent bond between two amino acid units, formed by a dehydration reaction |
primary structure | The level of protein stucture referring to the specific sequence of amino acids |
secondary structure | The localized, repetitive coiling or folding of the polypeptide backbone of a protein due to hydrogen bond formation between peptide linkages |
tertiary structure | Irregular contortions of a protein molecule due to interactions of side chains invovled in hydrophobic interactions, ionic bonds, hydrogen bonds, and disulfide bridges |
hydrophobic interaction | A type of weak chemical bond formed when molecules that do not mic with water coalesce to exlude the water |
disulfide bridge | A strong covalent bond formed when the sulfur of one cysteine monomer bonds to the sulfur of another cysteine monomer |
quaternary structure | The particular shape of a complex, aggregate protein, defined by the characteristic three-dimensional arrangement of its constituent subunits, each a polypeptide |
denaturation | In proteins, a process in which a protein unravels and loses its native conformation, thereby becoming biologically inactive. Denaturatoin occurs under extreme conditions of pH, salt concentration, and temperature |
chaperonin | A protein molecule that assists the proper folding of other proteins |
X-ray crystallography | A technique that depends on the diffraction of an X-ray beam by the individual atoms of a molecule to study the three-dimensional structure of the molecule |
gene | A discrete unit of hereditary information consisting of a specific nucleotide sequence in DNA (or RNA, in some viruses) |
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. The two types are DNA and RNA |
deoxyribonucleic acid (DNA) | A double- stranded, helical nucleic acid molecule capable of replicating and determining the inherited structure of a cell's proteins |
ribonucleic acid (RNA) | A type of nucleic acid consistinf of nucleotide monomers with a ribose sugar and the nitrogenous bases adenine (A), cytosine (C), guanine (G), and uracil (U); functions in protein synthesis and as the genome of some viruses |
polynucleotide | A polymer consisting of many nucleotide monomers; serves as a blueprint for proteins and through the actions of proteins, for all cellular activities. The two types are DNA and RNA |
nucleotide | The building block of a nucleic acid, consisting of a five-carbon sugar covalently bonded to a nitrogenous base and a phosphate group |
pyrimidine | One of two types of nitrogenous bases found in nucleotides. Cytosine (C), thymine (T), and uracil (U) are pyrimidines |
purine | One of two types of nitrogenous bases found in nucleotides. Adenine (A) and Guanine (G) are purines |
ribose | The sugar component of RNA |
deoxyribose | The sugar component of DNA, having one less hydroxyl group than ribose, the sugar component of RNA |
double helix | The form of native DNA, referring to its two adjacent polynucleotide strands wound into a spiral shape |
antiparallel | The opposite arrangement of the sugar-phosphate backbones in a DNA double helix |
alpha (α) helix | A spiral shape constituting one form of the secondary structure of proteins, arising from a specific hydrogen-bonding structure |
beta (β) pleated sheet | One form of the secondary structure of proteins inwhich the polypeptide chain folds back and forth. Two regions of the chain lie parallel to eah other and are held together by hydrogen bonds |