Chapter 3 - Molecules of Life

Question 1

Organic molecules consist mainly of ______________ atoms.

a. carbon
b. carbon and oxygen
c. carbon and hydrogen
d. carbon and nitrogen

Answer 1

c. carbon and hydrogen

Question 2

Each carbon atom can share pairs of electrons with as many as ________ other atom(s).

Answer 2

four

Question 3

___________ groups impart polarity to alcohols.

a. Hydroxyl (—OH-)
b. Phosphate (—PO4)
c. Methyl (—CH3)
d. Sulfhydryl (—SH)

Answer 3

a. Hydroxyl (—OH-)

Question 4

________ is a simple sugar (a monosaccharide).

a. Glucose
b. Sucrose
c. Ribose
d. Starch
e. both a and c
f. a, b, and c

Answer 4

e. both a and c

Question 5

Unlike saturated fats, the fatty acid tails of unsaturated fats incorporate one or more _________.

a. phosphate groups
b. glycerols
c. double bonds
d. single bonds

Answer 5

c. double bonds

Question 6

Is this statement true or false? Unlike saturated fats, all unsaturated fats are beneficial to health because their fatty acid tails kink and do not pack together.

Answer 6

False

Question 7

Steroids are among the lipids with no _____________.

a. double bonds
b. fatty acid tails
c. hydrogens
d. carbons

Answer 7

b. fatty acid tails

Question 8

Name three kinds of carbohydrates that can be built using only glucose monomers.

Answer 8

starch, glycogen, cellulose

Question 9

Which of the following is a class of molecules that encompasses all of the other molecules listed?

a. triglycerides
b. fatty acids
c. waxes
d. steroids
e. lipids
f. phospholipids

Answer 9

e. lipids

Question 10

__________ are to proteins as __________ are to nucleic acids.

a. Sugars; lipids
b. Sugars; proteins
c. Amino acids; hydrogen bonds
d. Amino acids; nucleotides

Answer 10

d. Amino acids; nucleotides

Question 11

A denatured protein has lost its _________.

a. hydrogen bonds
b. shape
c. function
d. all of the above

Answer 11

d. all of the above

Question 12

________ consists of nucleotides.

a. Sugars
b. DNA
c. RNA
d. b and c

Answer 12

d. b and c

Question 13

Which of the following is not found in DNA?

a. amino acids
b. sugars
c. nucleotides
d. phosphate groups

Answer 13

d. phosphate groups

Question 14

In the following list, identify the carbohydrate, the fatty acid, the amino acid, and the polypeptide:

a. NH2—CHR—COOH
b. C6H12O6
c. (methionine)20
d. CH3(CH2)16COOH

Answer 14

a. amino acid
b. carbohydrate
c. polypeptide
d. fatty acid

Question 15

Match the molecules with the best description.

\_\_\_\_ wax 
\_\_\_\_ starch
\_\_\_\_ triglyceride 
\_\_\_\_ DNA
\_\_\_\_ polypeptide 
\_\_\_\_ ATP

a. protein primary structure
b. an energy carrier
c. water-repellent secretions
d. carries heritable information
e. sugar storage in plants
f. richest energy source

Answer 15

c
e
f
d
a
b

Question 16

Match each polymer with the most appropriate set of component monomers.

\_\_\_\_ protein
\_\_\_\_ phospholipid
\_\_\_\_ glycoprotein
\_\_\_\_ fat
\_\_\_\_ nucleic acid
\_\_\_\_ carbohydrate
\_\_\_\_ nucleotide
\_\_\_\_ lipoprotein 
\_\_\_\_ sucrose

a. glycerol, fatty acids, phosphate
b. amino acids, sugars
c. glycerol, fatty acids
d. nucleotides
e. sugars
f. sugar, phosphate, base
g. amino acids
h. glucose, fructose
i. lipids, amino acids

Answer 16

g
b
d
f
a
c
e
i
h