Name:
The Chemistry of Life
Chapter 2.1-2.4 Review
Nature of Matter- Lesson 2.1
Determine if the statement is true. If it is not, rewrite the italicized part to make it true.
1. An element is a substance that can be broken down into simpler substances. _______________
2. Only four elements- carbon, hydrogen, oxygen, and nitrogen - make up more than 96 percent of
the mass of a human. ___________________
3. Each element is abbreviated by a one- or two- letter formula. __________________
4. Trace elements, such as iron and magnesium, are present in living things in very large amounts.
__________
Label the parts of the atom.
A.
B.
C.
D.
E.
Answer the following question.
10. Boron has two isotopes, boron- 10 and boron- 11. Boron-10 has five protons and five neutrons.
How many protons and neutrons does boron- 11 have? Explain your answer.
Write the type of substance described. Use these choices: compound, element.
11. H2O, a liquid that no longer resembles either hydrogen or oxygen. _____________________
12. A substance that can be broken down in a chemical reaction.______________________
13. Carbon, a substance represented by the symbol C. _______________________
Complete the table by checking the correct column for each description.
Statement Ionic Bond(s) Covalent Bond(s)
14. Found in the compound NaCl
15. Increases the stability of atoms.
16. Results in the formation of a molecule.
17. Is formed when atoms share electrons.
Properties of Water- Lesson 2.2
True/False- For each statement below, write true or false.
1. _______ In a water molecule, electrons are shared equally between the hydrogen atoms and
oxygen atoms.
2. _______ The attraction of opposite charges between hydrogen and forms a weak oxygen bond.
3. _______ Because of its polarity, water can move from the roots of a plant up to its leaves.
4. _______ Water changes temperature easily.
5. _______ Unlike most substances, water expands when it freezes.
Multiple Choice
6. _____ Cohesion is the attraction of molecules of _____________ substances.
a. different b. increasing c. the same d. colored
7. _____ An acid is a compound that has a higher concentration of H+ and a pH range of:
a. 6-8 b. 1-3 c. 1-14 d. 12-14
8. _____ A(n) _________ is a compound that prevents a sharp, sudden change in pH.
a. base b. solute c. buffer d. mixture
9. _____ Surface tension gives the ability for a bug to walk on the surface of water and is due to:
a. adhesion b. suspensions c. an acid d. cohesion
Short Answer
10. How does the structure of water contribute to its unique properties?
11. How does water’s polarity influence its properties as a solvent?
12. Why is it important for cells to buffer solutions against rapid changes in pH?
Carbon Compounds- Lesson 2.3
True/False- For each of the following statements about carbon, write true or false.
________ 1. Carbon atoms can bond together in straight chains, branched chains, or rings.
________ 2. Isomers are compounds with the same simple formula but different three-dimensional
structures.
________ 3. Large molecules containing carbon atoms are called micromolecules.
________ 4. Proteins are complex polymers.
Complete the tables
Write the name or formula under the correct heading. Use these items:
sucrose glucose starch C6H12O6 cellulose glycogen fructose C12H22O11
Monosaccharide Disaccharide Polysaccharide
6. Complete the table by checking the correct column for each description.
Statement Lipids Proteins Nucleic Acids
Made up of nucleotides
Consists of three fatty acids bonded to glycerol molecule
DNA and RNA
Contains peptide bonds
Forms the genetic code
Are commonly called fats and oils
Are used for long-term energy storage, insulation, and protective coating
Contain carbon, hydrogen, oxygen, and nitrogen
Enzymes & Reactions- Lesson 2.4
Matching
1. ______ activation energy a. process that changes one set of chemicals into others
2. ______ catalyst b. substance enters into a chemical reaction
3. ______ chemical reaction c. a chemical that speeds up the rate of a reaction
4. ______ enzyme d. produced in a chemical reaction
5. ______ product e. reactant of an enzyme-catalyzed reaction
6. ______ reactant f. energy needed to start a reaction
7. ______ substrate g. a protein catalyst that speeds up a biological reaction
Interpreting Graphs
Use the graph to answer the following questions about the effect of
enzymes on a chemical reaction.
8. Which curve shows the reaction pathway with the enzyme?
9. Which reaction has the higher activation energy?
10. Which arrow shows the activation energy with the enzyme A
or B?
11. Does this reaction absorb or release energy? How do you
know?
Short Answer
12. How do enzymes play a role in living things, and what affects their function?
13. Explain what happens if an enzyme that is optimized for a pH of 3 has an environment that has a
pH of 10. Why does this matter?
14. What is found in biological systems for the enzyme in question 13 to help it maintain its function?
Cut out the items dealing with the Molecules of Life and glue them in the correct places on the chart.
Cut this options out and paste them into page 4 of the document
Composed of
C,H,O,N,P
Carbohydrates Transfer of Nucleic acids
information
Keratin
Amylase (enzymes) DNA
Collagen Amino acids RNA Lipids
Hemoglobin
Fats Composed of
Oils C,H,O
Waxes Used for energy
Triglycerides
Steroids
Composed of Glucose, Fructose
C,H,O,N (maybe S) (monosaccharides Fatty acids &
Used for structure ) Glycerol
& function Maltose, Sucrose Hydrocarbon
(disaccharide) chains
Glycogen,
Cellulose
(polysaccharide)
Composed of
C,H,O Nucleotides Monosaccharides Proteins
Used for energy
storage,
protection,
insulation
