0610 Unit 4: Biological Molecules - Key Terms

amino acid

a monomer of a protein

antibody

proteins produced by lymphocytes

carbohydrate

a biological macromolecule in which the ratio of carbon to hydrogen to oxygen is 1:2:1; carbohydrates

catalyst

substance that speeds up the rate of a chemical reaction and is not changed by the reaction

cellulose

a polysaccharide that makes up the cell walls of plants and provides structural support to the cell

deoxyribonucleic acid (DNA)

a double-stranded polymer of nucleotides that carries the hereditary information of the cell

disaccharide

two sugar monomers that are linked together by a peptide bond

element

one of 118 unique substances that cannot be broken down into smaller substances and retain the characteristic of that substance; each element has a specified number of protons and unique properties

enzyme

a catalyst in a biochemical reaction that is usually a complex or conjugated protein

fat

a lipid molecule composed of three fatty acids and a glycerol (triglyceride) that typically exists in a solid form at room temperature

fatty acid

a substance produced when fats are digested (sub-units of fats)

gene

a length of DNA that codes for a protein

glucose

an example of a carbohydrate. It is a monosaccharide sugar

glycerol

Combines with fatty acids to make lipids.

glycogen

a storage carbohydrate in animals

haemoglobin

red

hormone

a chemical signaling molecule

insulation

the state of being separated and protected; material that protects against heat or electricity

lipids

a class of macromolecules that are nonpolar and insoluble in water

maltose

a disaccharide composed of two glucose units; sometimes known as malt sugar

monosaccharide

a single unit or monomer of carbohydrates

nucleic acid

a biological macromolecule that carries the genetic information of a cell and carries instructions for the functioning of the cell

nucleotide

a monomer of nucleic acids; contains a pentose sugar

oil

an unsaturated fat that is a liquid at room temperature

phospholipid

a major constituent of the membranes of cells; composed of two fatty acids and a phosphate group attached to the glycerol backbone

polypeptide

a long chain of amino acids linked by peptide bonds

polysaccharide

a long chain of monosaccharides; may be branched or unbranched

protein

a biological macromolecule containing the elements of carbon

ribonucleic acid (RNA)

a single-stranded polymer of nucleotides that is involved in protein synthesis

saturated fatty acid

a long-chain hydrocarbon with single covalent bonds in the carbon chain; the number of hydrogen atoms attached to the carbon skeleton is maximized

starch

a storage carbohydrate in plants

steroid

a type of lipid composed of four fused hydrocarbon rings

sucrose

a disaccharide of glucose + fructose

triglyceride

a fat molecule; consists of three fatty acids linked to a glycerol molecule

unsaturated fatty acid

a long-chain hydrocarbon that has one or more than one double bonds in the hydrocarbon chain