Carbohydrates, Lipids, and Nucleic Acids

Vocabulary

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

carbohydrate

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

cellulose

polysaccharide used for structure in plants

chitin

polysaccharide used for structure in some animals and fungi

cholesterol

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

glycogen

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

lipid

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

liposome

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

micelle

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

monosaccharide

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

monounsaturated

fat containing only a single double bond

nucleic acid

large molecule made of nucleotides

oligosaccharide

polysaccharide made up of just a few monosaccharides

phospholipid

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

polysaccharide

carbohydrate formed from many monosaccharides bonded together

polyunsaturated

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

starch

polysaccharide that stores energy in plants

steroid

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

sugar

common term referring to various monosaccharides or disaccharides

triacylglycerol

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