Mastering Biology 2

Mastering Biology 2 Which of these is NOT a lipid? a) RNA b) phospholipid c) steroids d) cholesterol e) wax - Answer-b) RNA Which of these is rich in unsaturated fats? a) beef fat b) olive oil c) lard d) a fat that is solid at room temperature e) butter - Answer-b) olive oil A function of cholesterol that does not harm health is its role _____. a) All of cholesterol's effects cause the body harm. b) the most abundant male sex hormone c) as a component of animal cell membranes d) in calcium and phosphate metabolism e) as the primary female sex hormone - Answer-c) as a component of animal cell membranes Proteins are polymers of _____. a) glycerol b) amino acids c) nucleotides d) CH2O units e) hydrocarbons - Answer-b) amino acids What type of bond joins the monomers in a protein's primary structure? a) S - S b) peptide c) hydrogen d) ionic e) hydrophobic - Answer-b) peptide The secondary structure of a protein results from _____. a) hydrophobic interactions b) bonds between sulfur atoms c) peptide bonds d) hydrogen bonds e) ionic bonds - Answer-d) hydrogen bonds Tertiary structure is NOT directly dependent on _____. a) bonds between sulfur atoms b) peptide bonds c) hydrophobic interactions d) ionic bonds e) hydrogen bonds - Answer-b) peptide bonds The bonding of two amino acid molecules to form a larger molecule requires a) both the release of a carbon dioxide molecule and the addition of a nitrogen atom. b) the release of a carbon dioxide molecule. c) the release of a water molecule. d) the addition of a water molecule. e) the addition of a nitrogen atom. - Answer-c) the release of a water molecule There are 20 different amino acids. What makes one amino acid different from another? a) different alpha carbons b) different side chains (R groups) attached to an alpha carbon c) different asymmetric carbons d) different amino groups attached to an alpha carbon e) different carboxyl groups attached to an alpha carbon - Answer-b) different side chains (R groups) attached to an alpha carbon Which type of interaction stabilizes the alpha helix and the beta pleated sheet structures of proteins? a) nonpolar covalent bonds b) hydrophobic interactions c) peptide bonds d) hydrogen bonds e) ionic bonds - Answer-d) hydrogen bonds Which of the following descriptions best fits the class of molecules known as nucleotides? a) a nitrogenous base and a phosphate group b) a nitrogenous base, a phosphate group, and a pentose sugar c) a nitrogenous base and a pentose sugar d) a pentose sugar and a purine or pyrimidine e) a phosphate group and an adenine or uracil - Answer-b) a nitrogenous base, a phosphate group, and a pentose sugar Which of the following statements best summarizes the structural differences between DNA and RNA? a) RNA is a protein, whereas DNA is a nucleic acid. b) DNA is a protein, whereas RNA is a nucleic acid. c) RNA is a double helix, but DNA is single-stranded. d) DNA nucleotides contain a different sugar than RNA nucleotides.