Biology: Chapter 3 - The Chemistry of Organic Molecules

ADP (Adenosine Diphosphate)

Nucleotide with two phosphate groups that can accept another phosphate group and become ATP.

Amino Acid

Organic molecule composed of an amino group and an acid group; covalently bonds to produce peptide molecules.

ATP (Adenosine Triphosphate)

Nucleotide with three phosphate groups. The break down of an ATP into and ADP + P makes energy available for energy-requiring process and cells.

Biomolecule

Organic molecules such as proteins, nucleic acids, carbohydrates, and fats.

Carbohydrate

Class of organic compounds that typically contain carbon, hydrogen, and oxygen in a 1:2:1 ratio; includes the monosaccharides, disaccharides, and polysaccharides.

Cellulose

Polysaccharides that is the major complex carbohydrate in the plant cell walls.

Chaperone Protein

Molecule that directs the proper folding of polypeptides.

Chitin

Strong and flexible nitrogenous polysaccharides found in the exoskelton of arthropods and in cell walls of fungi.

Coenzyme

Nonprotein organic molecule that aids the action of the enzyme to which it is loosely bound.

Complementary Base Pairing

Hydrogen bonding between particular purines and pyrimidines; responsible for the structure of DNA, and some RNA molecules.

Dehydration Reaction

Chemical reaction in which a water molecule is released during the formation of a covalent bond.

Denatured

Loss of a proteins or enzymes normal shape so that it no longer functions; usually caused by less than optimal pH and temperature.

Deoxyribose

Pentose sugar found in DNA.

Disaccharide

Sugar that contains two monosaccharide units.

DNA (Deoxyribonucleic Acid)

Nucleic acid polymer produces from covalent bonding of nucleotide monomers that contain the sugar deoxyribose; the gentic material of nearly all organisms.

Enzyme

Organic catalyst, usually a protein, that speeds the reaction in cells due to its particular shape.

Fat

Organic molecule that contains glycerol and three fatty acids; energy storage molecule.

Fatty Acid

Molecule that contains a hydrocarbon chain and ends with and acid group.

Fibrous Protein

A protein that has only a secondary structure; generally insoluble;includes collagens, elastins, and keratins.

Functional Group

Specific cluster of atoms attached to the carbon skeleton of organic molecules that enters into reactions and behaves in a predicatable way.

Globular Protein

Most of the proteins in the body; soluble in water or salt solutions; includes albumins, globulins, histones.

Glucose

Six-carbon monsaccharide; used as an energy source during cellular respiration and as a monomer of the structural polysaccharide.

Glycerol

Three-carbon carbohydrate with hydroxyl groups attached; a component of fats and oils.

Glycogen

Storage polysaccharides found in animals; composed of glucose molecules joined in a linear fashion but having numerous branches.

Hemoglobin (Hb)

Iron-containing respiratory pigment occurring in the vertebrate red blood cells and in blood plasma of some invertebrates.

Hexose

Any monosaccharide that contains six carbons; examples are glucose and gallactose.

Hydrolysis Reaction

Splitting of a chemical bond by the addition of water, with the H+ going to one molecule and the OH- going to another.

Hydrophilic

Type of molecule, often polar, that interacts with water by dissolving in water and/or by forming hydrogen bonds in water molecules.

Hydrophobic

Type of molecule, that is typically nonpolar, and therefore does not interact easily in water.

Inorganic Chemistry

Branch of science that studies the chemical reactions and properties of all elements, except hydrogen and carbon.

Isomer

Molecules with the same molecular formula but a different structure, and therefore a different shape.

Lipid

Class of organic compunds that tends to be soluble in nonpolar solvents; includes fats and oils.

Monomer

Small molecule that is a subunit.

Monosaccharide

Simple sugar; a carbohydrate that cannot be broken down by hydrolysis.

Nucleic Acid

Polymer of nucleotides; both DNA and RNA are nucleic acids.

Nucleotide

Monomer of DNA and RNA consisting of a five-carbon sugar bonded to a nitrogenous base and a phosphate group.

Oil

Triglyceride, usually of plant origin, that is composed of glycerol and three fatty acids and is liquid in consistency due to many unsaturated bonds in the hydrocarbon chains of fatty acids.

Organic Chemistry

Branch of science that deals with organic molecules including those that are unique to living things.

Organic Molecule

Molecule that always contains carbon and hydrogen, and often contains oxygen as well; organic molecules are associated with living things.

Pentose

Five-carbon monosaccharide. Examples are deoxyribose found in DNA and ribose found in RNA.

Peptide

Two or more amino acids joined by a covalent bond.

Peptide Bond

Type of covalent bond that joins amino acids.

Peptidoglycen

Polysaccharide that contains short chains of amino acids; found in bacterial cell walls.

Phosolipid

Molecule that forms the bilayer of the cell's membranes; has a polar, hydrophilic head bonded to 2 nonpolar, hydrophobic tails.

Polymer

Macromolecule consisting of covalently bonded monomers. For example, a polypeptide is a polymer of monomers, called amino acids.

Polysaccharide

Polymer made from carbohydrate monomers; the polysaccharides starch and glycogen are polymers of glucose monomers.

Prion

Infectious particle consisting of protein only and no nucleic acid.

Protein

Polymer of amino acids; often conisisting of one or more polypeptides and having a complex three-dimensional shape.

Ribose

Pentose sugar found in RNA.

RNA (Ribonucleic Acid)

Nucleic acid produced from covalent bonding of nucleotide monomers that contain the sugar ribose; occurs in many forms, including: messenger RNA, ribosomal RNA, and transfer RNA.

Saturated Fatty Acid

Fatty acid molecule that lacks double bonds between carbons of its hydrocarbon chain. The chain bears the minimum number of hydrogens possible.

Starch

Storage polysaccharide found in plants that is composed of glucose molecules joined in a linear fashion with few side chains.

Steroid

Type of lipid molecule having a complex of four carbon rings.

Trans-fat

Unsaturated fatty acid chains in which the configuration of the carbon-carbon double bonds in which the hydrogen atoms are across from each other, as opposed to being on the same side.

Triglyceride

Neutral fat composed of glycerol and three fatty acids; typically involved in energy storage.

Unsaturated Fatty Acid

Fatty acid molecule that contains double bonds between come carbons of its hydrogen chain; thus contains fewer hydrogens than a saturated hydrocarbon chain.

Wax

Sticky, solid, water repellent lipid consisting of many long chain fatty acids usully linked to long chain alcohols.