Carbohydrates, Lipids, and Nucleic Acids


adenosine diphosphate (ADP)

reduced form of the biological unit of energy, ATP. ADP has one less phosphate group than ATP.

adenosine triphosphate (ATP)

biological unit of energy, which consists of an adenosine (an adenine group and a ribose sugar) and three phosphate groups


organic molecule that contains carbon, hydrogen, and oxygen and provides energy to cells


polysaccharide used for structure in plants


polysaccharide used for structure in some animals and fungi


steroid lipid that helps with the production of steroid hormones and vitamins and controls cell membrane fluidity

deoxyribonucleic acid (DNA)

organic molecule containing coded instructions for the life processes of an organism, which consists of nucleotides bonded together in the form of a double helix

fatty acid

lipid consisting of a hydrophilic head made up of a carboxyl group (COOH{-}{\rm{COOH}}) and a hydrophobic tail made up of a hydrocarbon chain


polysaccharide that stores energy in animals

high-density lipoprotein (HDL)

structure containing a high proportion of proteins and some lipids that transports hydrophobic molecules in water


long-chain hydrocarbon that is soluble in nonpolar solvents; that is, solvents without charge

lipid bilayer

double layer of phospholipids that compose the cell membrane


small, fluid-filled sac surrounded by a phospholipid bilayer

low-density lipoprotein (LDL)

structure containing a high proportion of lipids and some proteins that transports hydrophobic molecules in water


aggregate of phospholipid molecules in water whose hydrophobic tails interact at the center


single sugar molecule, known also as a simple sugar. It is the most basic unit of carbohydrates.


fat containing only a single double bond

nucleic acid

large molecule made of nucleotides


polysaccharide made up of just a few monosaccharides


lipid molecule composed of glycerol (a carbon compound) bonded to two fatty acids and phosphate


carbohydrate formed from many monosaccharides bonded together


fat containing more than one double bond

ribonucleic acid (RNA)

organic molecule that carries genetic messages out of the nucleus; consists of a single strand of nucleic acids

saturated fatty acid

fatty acid with only single bonds, whose carbons are bonded with the maximum number of hydrogens


polysaccharide that stores energy in plants


lipid, such as cholesterol, containing three six-carbon rings and one five-carbon ring


common term referring to various monosaccharides or disaccharides


lipid composed of three fatty acid chains bonded to a glycerol head

unsaturated fatty acid

fatty acid that has one or more double bonds and thus fewer than the maximum number of hydrogens