Medical Biology_Mock Test #2

The bond that links the two monosaccharides of a disaccharide (glycoside)

• glycosidic linkage
• peptide bond
• disulfide linkage
• hydrogen bond
• no correct response

Which of the following carbohydrates does not belong to disaccharides?

• maltose
• cellobiose
• glycogen
• sucrose
• no correct response

The number of carboxyl groups and amino groups present, respectively, in a nonpolar amino acid is

• 1 and 1
• 2 and 1
• 1 and 2
• 2 and 2
• no correct response

How many different sub classifications are there for polar amino acids?

• 2.0
• 3.0
• 4.0
• 5.0
• 6.0

In this system, there are four categories: (1) nonpolar amino acids, (2) polar neutral amino acids, (3) polar acidic amino acids, and (4) polar basic amino acids. A nonpolar amino acid is an amino acid that contains _____ amino group, _____ carboxyl group, and a nonpolar side chain.

• one … one
• one … two
• two … one
• two … two
• no correct response

The lipids that form the main structural component of cell membranes are __________.

• Proteins
• Cholesterol
• Triacylglycerols
• Phospholipids
• Carbohydrates

Which of the following is a true statement comparing phospholipids and triacylglycerols (fats and oils)?

• Triacylglycerols may be saturated or unsaturated, but all phospholipids are saturated.
• Phospholipid molecules have a distinctly polar "head" and a distinctly nonpolar "tail," whereas triacylglycerols are predominantly nonpolar.
• In nature, phospholipids occur in fused rings (sterol form), whereas triacylglycerols maintain a straight-chain form.
• Both molecules contain a phosphate group.
• Phospholipids are the primary storage form for fats in our bodies.

Which of the following are pyrimidines found in the nucleic acid DNA?

• Uracil and guanine
• Thymine and cytosine
• Adenine and guanine
• Thymine and adenine
• Guanine and cytosine

Which of the following describes a difference between DNA and RNA?

• RNA molecules generally consist of a single polynucleotide chain, whereas DNA molecules generally consist of two polynucleotide chains organized into a double helix.
• Both molecules contain adenine, guanine, and cytosine, but DNA also contains thymine and RNA also contains uracil.
• They contain different sugars.
• The first and second listed responses correctly describe differences between DNA and RNA.
• The first three listed responses correctly describe differences between DNA and RNA.

Which of the following statements about the active site of an enzyme is correct?

• Coenzymes are rarely found in the active site of an enzyme.
• The active site allows the reaction to occur under the same environmental conditions as the reaction without the enzyme.
• The active site may resemble a groove or pocket in the surface of a protein into which the substrate fits.
• The active site has a fixed structure (shape).
• The structure of the active site is not affected by changes in temperature.