Name: ____________________________________ Date: ____________ Biology Period: ____
Unit 2: Chemistry of Life Study Guide
Scientific Method Review
A scientist wanted to test the effects of salt solutions on tomato plants. He inferred that higher
concentrations of salt water would make the plants produce more tomatoes.
a. List the independent variable. __________________________________
b. List the dependent variable.
__________________________________
Identify the 7 Characteristics of Life
1.
2.
3.
4.
5.
6.
7.

Section 2.1 Review
What is the relationship between an atom, an element, and a compound?
MATCH THE DESCRIPTION WITH THE
CORRECT LETTER FOR EACH PARTICLE OR
PARTICLES:
You can use them more than once!
E for ELECTRON
P FOR PROTON
N FOR NEUTRON


_______ positively charged
_______ orbits the nucleus in energy levels
_______ uncharged or neutral
_______ negatively charged
_______ & ______ found in the nucleus
ATOMS with an electric charge are called ________________.
Section 2.2 Review
The attraction between the hydrogen atom in one water molecule and the oxygen molecule in another
is an example of a ____________________ bond.
A. polymer
B. acidic
C. hydrogen
D. ionic

A water molecule is made up of ___________________________.
A. two hydrogen atoms and one oxygen atom
B. one hydrogen atom and two oxygen atoms
C. one hydrogen atom and 3 carbon atoms
D. two hydrogen atoms and 1 sodium ion

Short Answer: How is a water molecule like a magnet?
_________________________________________________________________________
_________________________________________________________________________

Match the characteristic of water with the description:
Cohesion
Adhesion
_________________
_______&_________
_________________
_________________
_________________
_________________
_________________
a.
b.
c.
d.
e.
f.
g.
Universal Solvent
High Specific Heat
A water bubble forms on top of a penny.
Water rises from the roots of a tree to the highest leaves.
Water is absorbed into a sponge.
Water molecules stick to other water molecules.
Water molecules stick to other substances due to its polar nature.
Water resists changes in temperature.
Many substances, for example salt and sucrose, dissolve quickly in water.
Section 2.3 Review
 NO other kind of atom can form the number and variety of molecules that ___________________
can because it can bond to 4 other atoms at the same time to make carbohydrates, lipids, nucleic
acids, and proteins.
A. Hydrogen
B. Oxygen
C. Carbon
D. Sodium

A(n) ____________________ is made up of a sugar, a nitrogen base, and a phosphate group.
A. amino acid
B. nucleotide
C. phospholipid
D. glycoprotein

Circle the nitrogen base found in DNA but NOT in RNA
Adenine
Thymine
Guanine
Cytosine
Uracil

Lipids are different from other macromolecules because they ___________________
A. are hydrophobic and don’t dissolve in water
B. contain carbon, hydrogen and oxygen in a ratio of 1:2:1
C. dissolve easily in water
D. form large protein molecules
E. are hydrophilic

Glycogen, cellulose, and starch are all __________________.
A. proteins
B. polysaccharides
C. nucleic acids
D. lipids

Adenine, thymine, guanine, cytosine, and uracil are all _____________________.
A. amino acids used to make proteins
B. carbohydrates used to make polysaccharides
C. lipids used to make phospholipids
D. nitrogen bases used to make nucleotides
MODIFIED TRUE or FALSE
Circle T if the statement is TRUE.
Circle F if the statement is FALSE and use the blank provided to correct the underlined word/phrase.
T
F
There are 20 different polysaccharides used to make proteins. ____________
T
F
Cellulose is a structural polysaccharide that makes plants sturdy. __________
T
F
One function of proteins is to provide insulation. __________________
T
F
People with diabetes can’t make hemoglobin to control their blood sugar. __________
Match the molecule with its description:
LIPIDS
CARBOHYDRATES
PROTEINS
NUCLEIC ACIDS
____________________________ made by joining amino acid subunits in long chains which provide
a wide variety of functions in cells
____________________________ made from carbon, hydrogen, and oxygen atoms in a 1:2:1 ratio
____________________________ made from nucleotide subunits which store and carry information
____________________________ Hydrophobic fats, oils, waxes, & steroids made mainly from
carbon and hydrogen atoms in long chains or multiple rings
Macromolecule
Monomer
Function
1. Carbohydrates
Stores energy for long-term
use
2.
3. Proteins
4.
nucleotides
NAME THE MOLELCULE DESCRIBED BELOW:
Protein hormone that tells animal cells to store blood glucose as glycogen
Double stranded nucleic acid made from nucleotides subunits containing A, T,
G, and C that stores genetic info in cells
Protein found in red blood cells that carries oxygen to the body
Single stranded nucleic acid made from nucleotide subunits containing A, U, C,
and G which carries information from the DNA to the cell for protein
synthesis
Storage form of glucose used by plant cells
Storage form of glucose used by animal cells
Structural polysaccharide made from glucose subunits that makes plants
sturdy
Polar molecule made from 1 oxygen and 2 hydrogen atoms that is required by
all living things
Section 2.4 Review
 Identify the reactants, yields sign, and the product in the chemical equation below.
2H2 + O2
 2H2O

Distinguish between endothermic and exothermic reactions.
Section 2.5 Review
Enzymes are biological catalysts. They are able to help chemical reactions in our bodies in several ways. Please
place a check beside each statement that is correct about enzymes.
_____ a.
_____ b.
_____ c.
_____ d.
_____ e.
_____ f.
correctly.
Enzymes lower the activation energy needed for a chemical reaction to begin.
Enzymes increase the rate of chemical reactions.
Almost all enzymes are carbohydrates.
Enzymes work very well in really hot temperatures.
Enzymes work well in our bodies at a pH of around 7.
If the structure of an enzyme is changed, then it cannot bond to a substrate and will not function
Based on the graphs shown below, indicate if the following statements are true or false.
Graph A
_____
_____
_____
_____
_____
a.
b.
c.
d.
e.
Graph B
Graph C
For an enzyme to function properly, it would prefer temperatures above 50°C.
As the concentration of enzymes increase, the rate of chemical reactions decreases.
The optimal temperature for an enzyme is 20°C.
Enzymes have the greatest activity level when conditions are very acidic.
The optimal pH for an enzyme is 8.
Substrate
a. An enzyme is a biological
_______________.
b. Like a key fits into a lock, substrates
exactly
fit the ____________ ________
of enzymes.
c. What will be true of an enzyme if the shape
is changed?
___________________________________
___________________________________