Question 1

Which of the following statements best explains why water is considered the 'universal solvent' in biological systems?

Accepted Answer

Water's polar covalent bonds allow it to disrupt ionic and polar covalent bonds, forming hydration spheres around solutes.

Question 2

A patient is diagnosed with acidosis. Which of the following best describes the patient's blood pH and the physiological consequences?

Accepted Answer

Blood pH is below 7.35, which can disrupt cell and tissue function by increasing H+ concentration.

Question 3

Which of the following best describes the difference between ionic and covalent bonds in biological molecules?

Accepted Answer

Ionic bonds result from the transfer of electrons and attraction between oppositely charged ions, while covalent bonds result from the sharing of electrons between neutral atoms.

Question 4

A molecule of glucose ($$\mathrm{C}_6\mathrm{H}_{12}\mathrm{O}_6) is $$dissolved in water. Which property of water allows glucose to dissolve, and what is the term for molecules that interact readily with water?

Accepted Answer

Water's polarity; hydrophilic

Question 5

Which of the following is a correct example of a decomposition (catabolic) reaction, and what is its significance in metabolism?

Accepted Answer

ABC yields A + B + C; it breaks down complex molecules into simpler ones, releasing energy.

Question 6

Which of the following best describes the structural difference between saturated and unsaturated fatty acids, and its effect on their physical state at room temperature?

Accepted Answer

Saturated fatty acids have only single carbon-carbon bonds and are solid at room temperature; unsaturated fatty acids have one or more double bonds and are liquid at room temperature.

Question 7

A protein is exposed to high heat, causing it to lose its three-dimensional structure. Which term describes this process, and what is the consequence for enzyme function?

Accepted Answer

Denaturation; the enzyme loses its ability to form enzyme-substrate complexes, shutting down the reaction.

Question 8

Which of the following statements about nucleic acids is correct regarding DNA and RNA?

Accepted Answer

DNA is a double-stranded helix with deoxyribose sugar, while RNA is a single-stranded chain with ribose sugar.

Question 9

Which of the following best explains why phospholipids form bilayers in plasma membranes?

Accepted Answer

Phospholipids have hydrophilic heads and hydrophobic tails, causing them to arrange with heads facing water and tails facing inward.

Question 10

A solution contains dispersed proteins that remain indefinitely without settling. What is this type of mixture called, and what is an example?

Accepted Answer

Colloid; Jell-O

Question 11

Which of the following best describes the role of enzymes in chemical reactions within the body?

Accepted Answer

Enzymes act as catalysts, lowering activation energy and accelerating biochemical reactions.

Question 12

Which of the following is true about the atomic structure of elements and their isotopes?

Accepted Answer

Isotopes of an element have the same number of protons but different numbers of neutrons, resulting in different mass numbers.

Question 13

Which of the following best describes the difference between exergonic and endergonic reactions in the context of metabolism?

Accepted Answer

Exergonic reactions release more energy than is required to run the reaction, while endergonic reactions require more energy than is produced.

Question 14

Which of the following is a correct example of chemical notation for an ionic compound dissociating in water?

Accepted Answer

$$\mathrm{NaCl} \rightarrow \mathrm{Na}^+ + \mathrm{Cl}^-$$

Question 15

Which of the following best describes the function of buffers in biological systems?

Accepted Answer

Buffers counter shifts in pH by releasing or binding hydrogen ions to maintain homeostasis.

Question 16

Which of the following best explains why water has a high heat capacity and how this property benefits the human body?

Accepted Answer

Hydrogen bonding between water molecules requires more energy to break, so water absorbs and retains heat, helping maintain stable body temperature.

Question 17

Which of the following is a correct example of dehydration synthesis in the formation of organic compounds?

Accepted Answer

The removal of water between two monomers to form a covalent bond, creating a polymer.

Question 18

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

Accepted Answer

Polymers are formed by covalently bonding monomers together through dehydration synthesis.

Question 19

Which of the following best describes the structure and function of ATP in cells?

Accepted Answer

ATP is a single nucleotide with three phosphate groups that releases energy when phosphates are removed.

Chapter 2: The Chemical Level of Organization – Study Notes

Study Guide - Practice Questions

Study Guide - Flashcards