Question 1

Which property of water allows it to move upward through the tiny vessels in a plant stem against gravity, and what is the main molecular interaction responsible for this phenomenon?

Accepted Answer

Capillary action; adhesion between water and vessel walls

Question 2

A scientist is analyzing an unknown organic molecule and finds it contains a carboxyl group ($$-COOH) $$and an amino group ($$-NH_2$). Which type of biomolecule is this most likely to be, and what is the bond formed between its monomers during polymerization?

Accepted Answer

Protein; peptide bond

Question 3

Which of the following best explains why water is considered the 'universal solvent'?

Accepted Answer

Water's polarity allows it to dissolve many ionic and polar substances.

Question 4

During a dehydration synthesis reaction, which of the following occurs?

Accepted Answer

A water molecule is removed to join two monomers, forming a covalent bond.

Question 5

Which functional group is present in all amino acids and is responsible for their acidic properties?

Accepted Answer

Carboxyl group ($$-COOH)$$

Question 6

A patient is diagnosed with a genetic disorder that affects the folding of proteins in their cells. Which level of protein structure is most directly affected by the interactions between R-groups (side chains) of amino acids?

Accepted Answer

Tertiary structure

Question 7

Which of the following statements about saturated and unsaturated fatty acids is correct?

Accepted Answer

Saturated fatty acids have no double bonds and are typically solid at room temperature.

Question 8

Which of the following best describes the difference in energy storage between lipids and carbohydrates?

Accepted Answer

Lipids store more energy per gram than carbohydrates because of their higher proportion of C-H bonds.

Question 9

A student tests an unknown solution with Benedict's reagent and observes a red color. What does this indicate about the solution?

Accepted Answer

It contains simple sugars (monosaccharides).

Question 10

Which of the following correctly matches a biomolecule with its monomer and the type of bond that links the monomers?

Accepted Answer

Nucleic acid; nucleotide; phosphodiester bond

Question 11

Which of the following is a function of phospholipids in living organisms?

Accepted Answer

Forming the main structural component of cell membranes

Question 12

A molecule is identified as a polysaccharide. Which of the following is most likely true about this molecule?

Accepted Answer

It is composed of monosaccharides joined by glycosidic bonds.

Question 13

Which of the following best explains why denaturation of a protein can lead to loss of function?

Accepted Answer

Denaturation alters the protein's three-dimensional shape, disrupting its active site or binding regions.

Question 14

Which of the following is NOT a component of a nucleotide?

Accepted Answer

A fatty acid chain

Question 15

A sample is tested with Lugol’s iodine and turns black. What does this indicate about the sample?

Accepted Answer

It contains starch (a polysaccharide).

Question 16

Which of the following best describes the role of carbon in organic molecules?

Accepted Answer

Carbon can form four covalent bonds, allowing for complex and diverse molecular structures.

Question 17

Which of the following best describes the difference between hydrolysis and dehydration synthesis?

Accepted Answer

Hydrolysis breaks polymers into monomers by adding water; dehydration synthesis joins monomers by removing water.

Question 18

Which of the following functional groups is found in both nucleic acids and phospholipids, and is important for energy transfer in cells?

Accepted Answer

Phosphate group ($$-PO_4$^{2-})$$

Question 19

A laboratory test using the Biuret reagent turns a solution purple. What does this result indicate about the solution?

Accepted Answer

It contains proteins.

Question 20

Which of the following best explains why ice floats on liquid water, and why this property is important for aquatic life?

Accepted Answer

Ice is less dense than liquid water because hydrogen bonds form a lattice structure, allowing ice to float and insulate the water below.

Chemistry of Life: Water, Functional Groups, and Biomolecules

Study Guide - Practice Questions

Study Guide - Flashcards