Part 1 Flashcards
Carbohydrate
A sugar (monosaccharide) or one of its dimers (disaccharides) or polymers (polysaccharides).
Cellulose
A structural polysaccharide of plant cell walls, consisting of glucose monomers joined by β glycosidic linkages.
Chitin
A structural polysaccharide, consisting of amino sugar monomers, found in many fungal cell walls and in the exoskeletons of all arthropods.
Cholestrol
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.
Dehydration reaction
A chemical reaction in which two molecules become covalently bonded to each other with the removal of a water molecule.
Disaccharide
A double sugar, consisting of two monosaccharides joined by a glycosidic linkage formed by a dehydration reaction.
Eukaryotic cell
A type of cell with a membrane-enclosed nucleus and membrane-enclosed organelles. Organisms with eukaryotic cells (protists, plants, fungi, and animals) are called eukaryotes.
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. Fatty acids vary in length and in the number and location of double bonds; three fatty acids linked to a glycerol molecule form a fat molecule, also called triacylglycerol or triglyceride.
Glycogen
An extensively branched glucose storage polysaccharide found in the liver and muscle of animals; the animal equivalent of starch.
Glycosidic Linkage
A covalent bond formed between two monosaccharides by a dehydration reaction.
Hydrolysis
A chemical reaction that breaks bonds between two molecules by the addition of water; functions in disassembly of polymers to monomers.
Lipid
Any of a group of large biological molecules, including fats, phospholipids, and steroids, that mix poorly, if at all, with water.
Macromolecule
A giant molecule formed by the joining of smaller molecules. Polysaccharides, proteins, and nucleic acids are macromolecules.
Monomer
The subunit that serves as the building block of a polymer.
Monosaccharide
The simplest carbohydrate, active alone or serving as a monomer for disaccharides and polysaccharides. Also called simple sugars, monosaccharides have molecular formulas that are generally some multiple of CH2O.
Phospholipid
A lipid made up of glycerol joined to two 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. Phospholipids form bilayers that function as biological membranes.
Polymer
A long molecule consisting of many similar or identical monomers linked together by covalent bonds.
Polysaccharide
A polymer of many monosaccharides, formed by dehydration reactions.
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.
Starch
A storage polysaccharide in plants, consisting entirely of glucose monomers joined by glycosidic linkages.
Trans fat
An unsaturated fat, formed artificially during hydrogenation of oils, containing one or more trans double bonds.
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.
