the arrangement of a polypeptide into a regular alpha helix, beta structure, or random coil configuration by the formation of intramolecular hydrogen bonds along the length of the chain.
The protein structure characterized by folding of the peptide chain into an alpha helix, beta sheet, or random coil. See also primary structure, quaternary structure, tertiary structure.
The folded, helical structure of double-stranded DNA.
- Secondary succession
secondary succession See under succession.
noun, Pathology. 1. the second stage of syphilis, characterized by eruptions of the skin and mucous membrane. secondary syphilis n. The second stage of syphilis, beginning with the appearance of the dermatologic eruption, slight fever, and various constitutional symptoms.
noun, Botany. 1. tissue derived from cambium.
- Secondary tuberculosis
secondary tuberculosis n. Tuberculosis occurring in adults and characterized by lesions near the apex of an upper lobe of the lung that may cavitate or heal with scarring; it may be result from reinfection with the tubercle bacillus or from reactivation of a dormant endogenous infection.