24 Key Terms
- active site
- location on an enzyme configured to bind a substrate
- alpha-helix structure (α-helix)
- type of secondary protein structure formed by folding the polypeptide into a helix shape with hydrogen bonds stabilizing the structure
- amino acid
- a protein’s monomer; has a central carbon or alpha carbon to which an amino group, a carboxyl group, a hydrogen, and an R group or side chain are attached; the R group is different for all 20 common amino acids
- beta-pleated sheet (β-pleated)
- secondary structure in proteins in which hydrogen bonding forms “pleats” between atoms on the polypeptide chain’s backbone
- biological macromolecule
- large molecule necessary for life that is built from smaller organic molecules
- carbohydrate
- biological macromolecule in which the ratio of carbon to hydrogen and to oxygen is 1:2:1; carbohydrates serve as energy sources and structural support in cells and form arthropods’ exoskeleton
- cellulose
- polysaccharide that comprises the plant’s cell wall; provides structural support to the cell
- chaperone
- (also, chaperonin) protein that helps nascent protein in the folding process
- chitin
- type of carbohydrate that forms the outer skeleton of all arthropods including crustaceans and insects; it also forms fungi cell walls
- chromatin
- complex of histone proteins and DNA, the substance of eukaryotic chromosomes
- chromosome
- structure composed of DNA and histone proteins, containing genetic information
- dehydration synthesis
- (also, condensation) reaction that links monomer molecules, releasing a water molecule for each bond formed
- denaturation
- loss of shape in a protein as a result of changes in temperature, pH, or chemical exposure
- deoxyribonucleic acid (DNA)
- double-helical molecule that carries the cell’s hereditary information
- disaccharide
- two sugar monomers that a glycosidic bond links
- enzyme
- catalyst in a biochemical reaction that is usually a complex or conjugated protein
- genome
- a cell or organism’s entire genetic content
- glycogen
- storage carbohydrate in animals
- glycosidic bond
- bond formed by a dehydration reaction between two monosaccharides, involving eliminating a water molecule
- hormone
- chemical signaling molecule, usually protein or steroid, secreted by endocrine cells that act to control or regulate specific physiological processes
- hydrolysis
- reaction that causes breakdown of larger molecules into smaller molecules by utilizing water
- hydrolysis reactions
- breaking a large molecule into smaller molecules by adding and splitting a water molecule
- lipid
- macromolecule that is nonpolar and insoluble in water
- messenger RNA (mRNA)
- RNA that carries information from DNA to ribosomes during protein synthesis
- monomer
- smallest unit of larger molecules that are polymers
- monosaccharide
- single unit or monomer of carbohydrates
- nucleic acid
- biological macromolecule that carries the cell’s genetic blueprint and carries instructions for