Biology Chapter 5
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56 terms
Terms | Definitions |
|---|---|
 Macromolecules | a giant molecule formed by the joining of smaller molecules, usually by a dehydration reaction, examples: Polysaccharides, proteins, and nucleic acids |
| Polymer | a long molecule consisting of many similar or identical building blocks linked by covalent bonds |
| Monomers | the subunit that serves as the building block of a polymer |
| Enzymes | specialized macromolecules that speed up chemical reactions |
| Dehydration reaction | a chemical reaction in which 2 molecules become covalently bonded to each other with the removal of a water molecule |
| Hydrolysis | a process that is essentially the reverse of the dehydration reaction |
| Carbohydrates | includes both sugars and polymers of sugars |
| Monosaccharides | the simplest carbohydrate, active alone or serving as a monomer for disaccharides and polysaccharides, also known as simple sugars, have molecular formulas that are generally some multiple of CH2O |
| Disaccharide | consists of 2 monosaccharides joined by a glycosidic linkage |
| Glycosidic linkage | a covalent bond formed between 2 monosaccharides by a dehydration reaction |
| Polysaccharides | are macromolecules, polymers with a few hundred to a few thousand monosaccharides joined by glycosidic linkages |
| Starch | a storage polysaccharide in plants, consisting entirely of glucose monomers joined by alpha glycosidic linkages |
| Glycogen | a polymer of glucose that is like amylopectin but more extensively branched |
| Cellulose | a structural polysaccharide of plant cell walls, consisting of glucose monomers joined by beta glycosidic linkages |
| Chitin | the carbohydrate used by anthropods to build their exoskeletons |
| Lipids | any of a group of large biological molecules, including fats, phosopholipids, and steroids, that mix poorly, if at all, with water |
| Fat | is constructed from 2 kinds of smaller molecules: glycerol and fatty acids |
| Fatty acid | a carboxylic acid with a long carbon chain, vary in length and in the number and location of double bonds |
| Triacylglycerol | a lipid consisting of 3 fatty acids linked to one glycerol molecule, also called a 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 that are 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 bonding reduces the number of hydrogen atoms attached to the carbon skeleton |
| Trans fats | an unsaturated fat, formed artificially during hydrogenation of oils, containing one or more trans double bonds |
| Phospholipids | a lipid made up of glycerol joined to 2 fatty acids and a phosphate group, the hydrocarbon chains of the fatty acids act as nonpolar, hydrophobic tails, while the rest of the molecule acts as a polar, hydrophilic head, form bilayers that function as biological membranes |
| Steroids | a type of lipid characterized by a carbon skeleton consisting of 4 fused rings with various chemical groups attached |
| Cholesterol | a steroid that forms as essential component of animal cell membranes and acts as a precursor molecule for the synthesis of other biologically important steroids, such as many hormones |
| Catalysts | a chemical agent that selectively increase the rate of a reaction without being consumed by the reaction |
| Polypeptides | 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 3-D structure |
| Enzymatic proteins | selective acceleration of chemical reactions, example: digestive enzymes catalyze the hydrolysis of bonds in food molecules |
| Defensive proteins | protection against disease, example: antibodies inactivate and help destroy viruses and bacteria |
| Storage proteins | storage of amino acids, examples: casein, the protein of milk, is the major source of amino acids for baby mammals, plants have these in their seeds |
| Transport proteins | transport of substances, example: hemoglobin, the iron-containing protein of vertebrae blood, transports oxygen from the lungs to other parts of the body |
| Hormonal proteins | coordination of an organism's activities, example: insulin, a hormone secreted by the pancreas, causes other tissues to take up glucose, thus regulating blood sugar concentration |
| Receptor proteins | response of cell to chemical stimuli, example: receptors built into the membrane of a nerve cell detect signaling molecules released by other nerve cells |
| Contractile and motor proteins | movement, example: motor proteins are responsible for the undulations of cilia and flagella, actin and myosin are responsible for the contraction of muscles |
| Structural proteins | support, example: keratin is the protein of hair, horns, feathers and other skin appendages |
| Nonpolar side chains; hydrophobic | glycine, alanine, valine, leucine, isoleucine, methionine, phenylalanine, tryptophan, proline |
| Polar side chains, hydrophilic | Serine, threonine, cysteine, tyrosine, asparagine, glutamine |
| Electrically charged side chains, hydrophilic [Acidic] | Aspartic acid, glutamic acid |
| Electrically charged side chains, hydrophilic [Basic] | Lysine, arginine, histidine |
| Peptide bond | the covalent bond between the carboxyl group on one amino acid and the amino group on 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 chains, including hydrophobic interactions, ionic bonds, hydrogen bonds, and disulflide bridges |
| Quaternary structure | the particular shape of a complex, aggregate protein, defined by the characteristic 3-D arrangement of its constituent subunits, each a polypeptide |
| Denaturation | 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 2 strands of the double helix, occurs under extreme conditions of pH, salt concentration, or temperature |
| Chaperonins | protein muscles that assist in the proper folding of other proteins |
| Nucleic acids | are polymers made of monomers called nucleotides |
| RNA | ribonucleic acid |
| Polynucleotides | a polymer consisting of many nucleotide monomers in a chain, the nucleotides can be those of DNA or RNA, only has one phosphate group |
| Nucleotides | is composed of 3 parts, a nitrogen containing base, a 5-carbon sugar, and one or more phosphate groups |
| Pyrimidine | has one 6-membered ring of carbon and nitrogen atoms, members of the pyrimidine family are cytosine, thymine, and uracil |
| Purines | larger than pyrimidines, with a 6-membered ring fused to a 5-membered ring, members of the purines are adenine and guanine |
| Deoxyribose | sugar found in DNA |
| Ribose | sugar found in RNA |
| Antiparallel | refers to the arrangement of the sugar-phosphate backbones in a DNA double helix |
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