Unit 1: Chemistry of Life

Based on the data, which property of water best explains the observed temperature stability in the beaker?

Which molecular interaction is most directly responsible for the difference in heating rates observed in this experiment?

If the experiment were repeated at a location near the ocean versus a location in the interior of a desert, how would the daily temperature range most likely compare?

Which of the following is a property of water that allows insects such as water striders to walk on its surface?

A polypeptide chain is formed by linking amino acids together. Which type of bond directly connects one amino acid to the next in the primary structure?

A protein is denatured by heating to 95°C. Which level(s) of protein structure are most likely disrupted?

Which of the following elements is found in proteins but NOT in carbohydrates?

A researcher measures the pH of a solution and finds it to be 4. If the pH is raised to 6, how does the hydrogen ion concentration change?

An enzyme functions optimally at pH 2 in the stomach. If this enzyme were placed in the small intestine at pH 8, what would most likely happen?

During a dehydration synthesis reaction between two glucose molecules, which of the following occurs?

Which of the following best describes the relationship between monomers and polymers?

Phospholipids are amphipathic molecules. This property is essential for which cellular function?

At what substrate concentration does the enzyme appear to reach approximately half of its maximum reaction rate?

If a competitive inhibitor is added to the reaction, which change in the data would you expect?

The leveling off of reaction rate at high substrate concentrations is best explained by which of the following?

Which functional group, when added to a molecule, would make the molecule act as an acid in solution?

A researcher discovers a new organic molecule with the empirical formula C₃H₇NO₂. Based on this formula, the molecule is most likely which type of macromolecule monomer?

Cellulose and starch are both polymers of glucose. Which structural difference best explains why humans can digest starch but not cellulose?

A solution has a hydrogen ion concentration of 10⁻⁹ M. What is the pH of this solution?

A tripeptide is formed from three amino acids. How many water molecules are released during its formation?

Based on the test results, which macromolecule is present in Sample 2?

The negative Benedict's test result for all three samples indicates that

If amylase (a starch-digesting enzyme) were added to Sample 1 and incubated, then retested, which change in test results would be expected?

Which functional group is found in all amino acids?

A scientist denatures a protein by heating it to 95°C. Which level of protein structure is most likely preserved?

Which of the following distinguishes DNA from RNA?

An enzyme has an optimal pH of 2.0 and is most active in an environment with high HCl concentration. This enzyme most likely functions in the

Which type of bond holds the two strands of a DNA double helix together?

Saturated fatty acids differ from unsaturated fatty acids in that saturated fatty acids

A mutation changes a single amino acid in an enzyme from a nonpolar residue in the interior to a charged residue. This is most likely to disrupt which level of protein structure?

A polypeptide contains 150 amino acids. How many peptide bonds are present in this polypeptide? Express as a whole number.

Lactose is a disaccharide composed of glucose and galactose. The bond linking these two monosaccharides is a

Which property of water is most directly responsible for its ability to moderate temperature changes in organisms?

A strand of DNA has the sequence 5'-ATGCCG-3'. How many hydrogen bonds hold this segment to its complementary strand? Express as a whole number.

A competitive inhibitor of an enzyme works by

A researcher measures the rate of an enzyme-catalyzed reaction at increasing substrate concentrations while keeping enzyme concentration constant. The rate initially increases linearly, then levels off at V_max. Which of the following best accounts for the leveling off?

Which of the following best explains why phospholipids spontaneously form bilayers in aqueous solutions?

A globular protein is found to have many nonpolar amino acid residues in its interior and charged residues on its surface. This arrangement is most directly explained by: