Chapter 2 – The Chemistry of Life
Study Guide
1. A solution with a high concentration of H ions is (very acidic/very basic).
2. Chemical reactions that absorb more energy than they release are (endergonic/exergonic).
3. The first carbon compounds that scientists studied are called __________________________
compounds because they came from living compounds.
4. DNA and RNA are two types of _________________________ (Look in your notes at the 4 Major
Classes of Organic Molecules).
5. What is the process that changes one set of chemicals into another set of chemicals?
6. When salt is dissolved in water, water is the (solvent/solute)?
7. Enzymes affect chemical reactions in living organisms by
a. Changing the direction of a reaction
b. Breaking down molecules into starch
c. Weakening bonds in reactants
d. Increasing the temperature range
8. How many atoms of oxygen and hydrogen make up a molecule of water?
9. __________________________ cannot be broken down by ordinary chemical means.
10. __________________________ bonds hold molecules together.
11. The three particles that make up an atom are ___________________________________________.
12. What type of ion forms when an atom loses electrons (positive/negative)?
13. __________________________ represents a formula for a chemical compound.
a. H
b. H2O
c. C
d. P
14. Which of the following solutions has the highest H ion concentration?
a. A solution with a pH of 7
b. A solution with a pH of 1
c. A solution with a pH of 4
d. A solution with a pH of 10
15. What are the four main groups of carbon-based molecules?
16. The activation energy needed for a chemical reaction is decreased by a
________________________________.
17. ________________________________ describes a substance formed by the combination of two or
more elements in definite proportions.
18. The most abundant compound in most living things is ___________________________.
19. What category of carbon-molecules includes sugars and starches?
20. Fats, oils, and cholesterol are all types of _____________________________________.
21. What gives water many properties that are important to living things?
a. Temperature
b. Hydrogen bonds
c. Specific heat
d. Density
22. In chemical reactions, atoms are _____________________________________.
23. Circle the reactants and underline the products: 6 H2O + 6 CO2  C6H12O6 +6 O2
24. Proteins are composed of what type of molecule?
25. Chemical reactions change substances into different substances by
______________________________________.
26. A very strong base might have a pH of __________________________________.
27. Which phrase best describes the effect of a catalyst on a chemical reaction?
a. Increases the volume of reactants
b. Decrease the activation energy
c. Decreases the reaction rate
d. Increases the temperature
28. The four main types of carbon-based molecules in organisms are carbohydrates, lipids, nucleic acids,
and _______________________________.
29. When hydrogen and oxygen combine to form water, water is (product/reactant).
30. Which property of carbon makes it the “building block of life”?
a. Specific heat
b. Hydrogen bonding
c. Covalent bonding
d. Ability to dissolve substances
31. Which phrase best describes atoms?
a. Smallest basic unit of matter
b. Positively charged particles
c. Single-celled organisms
d. Parts of a nucleus
32. The attraction among molecules of different substances is called ____________________________.
33. Which of the following phrases best describes a solvent?
a. Present in a greater concentration than solutes
b. Can be dissolved by the solute
c. Has a high concentration of solutes
d. Usually a sugar or a protein
34. Suspensions are mixtures of _______________________________________________________.
35. What is the term for the amount of energy that needs to be added for a chemical reaction to start?
36. What organic compound is the main source of energy for living things?
37. The nucleus is made up of ______________________________________________.
38. Ice floats on water because
a. Water shrinks when it freezes
b. Water expands when it freezes
c. Of cohesion
d. Ice has a higher density than water
39. Which property of water is the result of hydrogen bonds?
a. Low boiling point
b. High specific heat
c. No cohesion among water molecules
d. Polarity of water molecules
40. What are the basic building blocks of proteins?
41. A monosaccharide is the basic building block of which major organic compound.
42. Which of the following is NOT a function of proteins?
a. Help fight disease
b. Store and transmit heredity
c. Control the rate of reactions and regulate cell processes
d. Build tissues such as bone and muscle
43. How do ions form?
44. A substance with a pH of 6 is called ______________________________________.
45. A covalent bond is formed as the result of ____________________________________________.
46. A solution is a(n) ________________________________________________________.