$$\mathrm{C_6H_{12}O_6$} + 6\mathrm{O_2$} \rightarrow 6\mathrm{H_2O} + 6\mathrm{CO_2$} + \text{energy}$$

Question 1

Which statement best explains why ice floats on water?

Accepted Answer

Ice is less dense than liquid water because stable hydrogen bonds hold water molecules apart, creating more space between them.

Question 2

Which of the following is NOT a property of water that is important for life?

Accepted Answer

Water molecules do not form hydrogen bonds.

Question 3

What type of chemical bond involves the sharing of electrons between atoms?

Accepted Answer

Covalent bond

Question 4

Which element is able to form large, branched, and diverse molecules, making it essential for life on Earth?

Accepted Answer

Carbon

Question 5

A nitrogen atom has 7 protons, 8 neutrons, and 10 electrons. What is its charge?

Accepted Answer

It is negatively charged.

Question 6

Which of the following best describes a polymer?

Accepted Answer

A molecule created by joining together smaller molecules called monomers.

Question 7

Which process breaks down polymers into monomers in the digestive system?

Accepted Answer

Hydrolysis

Question 8

Which of the following is a correct chemical equation for the rearrangement of matter in cellular respiration?

Accepted Answer

$$\mathrm{C_6H_{12}O_6$} + 6\mathrm{O_2$} ightarrow 6\mathrm{H_2O} + 6\mathrm{CO_2$} + 	ext{energy}$$

Question 9

Which type of bond is the strongest among chemical bonds?

Accepted Answer

Covalent bond

Question 10

What is the main reason water is an effective solvent?

Accepted Answer

Water molecules form hydrogen bonds due to their polarity.

Question 11

Which of the following statements about acids and bases is correct?

Accepted Answer

Acids release H+ ions when dissolved in water.

Question 12

What is the function of buffers in biological systems?

Accepted Answer

Buffers minimize changes in pH by accepting H+ ions.

Question 13

Which class of organic molecules is most directly involved in speeding up chemical reactions in cells?

Accepted Answer

Proteins (enzymes)

Question 14

Which of the following is a correct description of a saturated fat?

Accepted Answer

Contains only single bonds and is solid at room temperature.

Question 15

What is the role of cholesterol in animal cell membranes?

Accepted Answer

It maintains membrane fluidity.

Question 16

Which process links two monomers together and removes a molecule of water?

Accepted Answer

Dehydration synthesis

Question 17

Which of the following best describes the relationship between enzyme shape and function?

Accepted Answer

Enzyme function depends on its precise shape and amino acid sequence.

Question 18

Which of the following is a real-world consequence of increased CO2 in the atmosphere?

Accepted Answer

Ocean water becomes more acidic, impairing the ability of marine organisms to build skeletons or shells.

Question 19

Which of the following is a correct statement about the pH scale?

Accepted Answer

Each number on the pH scale represents a tenfold change in H+ ion concentration.

Chapter 2: The Chemistry of Life – Study Notes

Study Guide - Practice Questions