The phosphodiester bonds that link adjacent nucleotides in both RNA and DNA: a. always link A with T and G with C. b. are susceptible to alkaline hydrolysis. c. are uncharged at neutral pH. d. form between the planar rings of adjacent bases. e. join the 3' hydroxyl of one nucleoside to the 5' hydroxyl of the next.

The following are the four bases found in DNA. Which base pair can form three hydrogen bonds? * NH2 NH2 CH3. N. NH 'N. NH N, NH2 O. adenine (A) guanine (G) cytosine (C) thymine (T) A-C O A-T G-C O G-T

HO What type of nucleotide is shown? a. RNA and a Purine b. DNA and a Purine Oc. RNA and a Pyrimidine Od. An Uracil e. DNA and a Pyrimidine NH₂

Arginine is considered a basic amino acid because its side chain ________ at physiological conditions (around pH 7). a. is protonated b. has a low pKa c. proton is titrated away d. is hydrophobic

Which of the following is incorrect about the beta-sheet? a. The strands in anti-parallel beta-sheets are usually connected with turns b. Side chains are alternated above and below the sheet C. Parallel beta-sheets are less stable than the anti-parallel ones Od. It is stabilized by hydrophobic interactions between the side chains of nonpolar residues

A protein is made up for two polypeptides that differ in shape.  Each polypeptide has one domain.  Which of the following is NOT true? a. the protein is stabilized by hydrogen bonds b. the two polypeptide are encoded by the same gene c. the protein has quaternary structure d. none of the above e. the protein is a heterodimer

Which of the following is incorrect about the peptide Arg-Asp-Cys-Tyr-Gln-Arg-Glu? It has six peptide bonds b. It has a net charge of zero at pH 7 It has six charged groups at pH 7 d. None; all the other choices are correct a. C.

An allosteric interaction between a ligand and a protein is one in which: a. binding of a molecule to a binding site affects binding of additional molecules to the same site. b. binding of a molecule to a binding site affects binding properties of another site on the protein. c. binding of the ligand to the protein is covalent. d. multiple molecules of the same ligand can bind to the same binding site. e. two different ligands can bind to the same binding site.