6. A ceramide is derived from which combination of the following?(A) A molecule of sphingosine and a monosaccharide(B) A molecule of sphingosine and a molecule of phosphocholine(C) A molecule of sphingosine and a fatty acid(D) A molecule of sphingosine and two fatty acids(E) A molecule of sphingosine, a fatty acid and a monosaccharide

7. DNA double helix structure is stabilized by all of the following EХСЕРТ:(A) the sugar-phosphate backbones are oriented in opposite directions.(B) the glycosidic bonds holding paired bases are directly across the helix from one another.(C) cations such as Mg2+ bind to the anionic phosphates.(D) bases stack together through hydrophobic interactions and van der Waals forces.(E) appropriate base pairing builds a polymer whose external dimensions are uniform.

相關試題

相關試卷