5 and 6

Question 1

A simple sugar is found to have the chemical structure C6H12O6. This molecule can
most confidently be defined as ________.
A) a hexose
B) a pentose
C) an aldose
D) a ketose
E) a polysaccharide

Answer 1

A) a hexose

Question 2

Which of the following can vary among monosaccharides?
A) The number of carbon atoms
B) The presence of a carbonyl group
C) The presence of hydroxyl groups
D) The presence of sulfur groups

Answer 2

A) The number of carbon atoms

Question 3

Which of these best reflects the following relationship: monosaccharide versus
polysaccharide?
A) Glucose versus glycogen
B) Glucose versus fructose
C) 1,4-glycosidic linkage versus 1,6-glycosidic linkage
D) α-linkage versus β-linkage

Answer 3

A) Glucose versus glycogen - simple sugar vs complex structure that stores sugar for later

Question 4

During a dehydration reaction that converts two monosaccharides into a
disaccharide, what functional groups are involved in this reaction?
A) A hydroxyl group from each monosaccharide
B) A hydroxyl group from one monosaccharide and a phosphate group from the other
C) An amino group from one monosaccharide and a carboxyl group from the other
D) A carbonyl group from one monosaccharide and a hydroxyl from the other
E) An amino acid chain from one monosaccharide links to a similar chain from the other

Answer 4

A) A hydroxyl group from each monosaccharide

Question 5

All of the following are polysaccharides EXCEPT ________.
A) lactose
B) glycogen
C) chitin
D) cellulose
E) amylopectin

Answer 5

A) lactose

Question 6

Which of the following categories includes all others in the list?
A) Monosaccharide
B) Disaccharide
C) Starch
D) Carbohydrate
E) Polysaccharide

Answer 6

D) Carbohydrate

Question 7

A phospholipid is a ________.
A) nonpolar lipid molecule that is made polar by the addition of a phosphate
B) nonpolar lipid molecule that is made amphipathic by the addition of a phosphate
C) polar lipid molecule that fully interacts with water
D) polar lipid molecule that fully repels water

Answer 7

B) nonpolar lipid molecule that is made amphipathic by the addition of a phosphate

Question 8

Which of the following accurately describes a reason why fats store more energy
than carbohydrates?
A) Fats molecules are always larger than carbohydrate molecules.
B) Compared to carbohydrates, fatty acid chains have a higher ratio of bonds with high
potential energy to bonds with low potential energy.
C) Fatty acid chains have more carbon-carbon bonds than carbohydrates.
D) Carbohydrates can be incorporated into polymers through dehydration reactions, while
fats cannot form polymers.
E) Fats contain more polar groups than carbohydrates.

Answer 8

B) Compared to carbohydrates, fatty acid chains have a higher ratio of bonds with high
potential energy to bonds with low potential energy.

Question 9

Lipids ________.
A) are insoluble in water
B) are made from glycerol, fatty acids, and nitrogen
C) contain less energy than proteins and carbohydrates
D) are made by dehydration reactions
E) contain sulfur polymers

Answer 9

A) are insoluble in water

Question 10

A major feature of phospholipids that causes a portion of their structure to be
hydrophilic is ________.
A) the glycerol backbone
B) the unsaturated fatty acid tails
C) the phosphate group
D) the ester linkages
E) the saturated fatty acid tails

Answer 10

C) the phosphate group

Question 11

The presence of cholesterol in the plasma membranes of some animal cells
________.
A) enables the membranes to stay fluid when cell temperature drops
B) enables the cell to remove hydrogen atoms from saturated phospholipids
C) enables the cell to add hydrogen atoms to unsaturated phospholipids
D) makes the cell membrane less flexible, allowing it to sustain greater intracellular
pressure
E) reduces mutations to genetic material inside the cell

Answer 11

A) enables the membranes to stay fluid when cell temperature drops

Question 12

Lipids that form membranes have what kind of structure?
A) Polar heads and polar tails, which allows them to interact with water on both sides of the
membrane.
B) Completely polar, which allows them to dissolve in water.
C) Polar heads and nonpolar tails; the nonpolar tails interact with water.
D) Polar heads and nonpolar tails; the polar heads interact with water

Answer 12

D) Polar heads and nonpolar tails; the polar heads interact with water

Question 13

Which aspect of phospholipids is most important to the formation of bilayers?
A) They are amphipathic.- having both hydrophilic and hydrophobic parts.
B) Their polar heads can interact with water.
C) The length of their hydrocarbon tails can be altered to modulate membrane fluidity.
D) Their hydrocarbon tails can consist of fatty acids or isoprene subunits.

Answer 13

A) They are amphipathic.- having both hydrophilic and hydrophobic parts.

Question 14

Which of the following crosses lipid bilayers the fastest?
A) A sodium ion
B) A small, polar molecule like water
C) A large, polar molecule like glucose
D) A small, nonpolar molecule like oxygen (O2)

Answer 14

D) A small, nonpolar molecule like oxygen (O2)

Question 15

Which of the following crosses lipid bilayers the slowest?
A) A sodium ion
B) A small, polar molecule like water
C) A large, polar molecule like glucose
D) A small, nonpolar molecule like oxygen (O2)

Answer 15

A) A sodium ion

Question 16

Which of the following types of molecules are the major structural components of
the cell membrane?
A) Phospholipids and cellulose
B) Nucleic acids and proteins
C) Phospholipids and proteins
D) Proteins and cellulose

Answer 16

C) Phospholipids and proteins

Question 17

Your study partner has drawn four models of membrane-bound vesicles to try to
show what a vesicle would look like with water both inside and outside of the
membrane. Help him to select the most accurate model.

Answer 17

C

Question 18

Which of the following increases the strength of the hydrophobic interactions in
lipid bilayers and thus makes them less permeable to polar molecules?
A) The presence of double bonds
B) Increasing temperature
C) Removing cholesterol
D) Increasing length of the hydrocarbon chains

Answer 18

D) Increasing length of the hydrocarbon chains

Question 19

Cooking oil and gasoline (a hydrocarbon) are NOT amphipathic molecules because
they
________.
A) do not have a polar or charged region
B) do not have a nonpolar region
C) have hydrophobic and hydrophilic regions
D) are highly reduced molecules

Answer 19

A) do not have a polar or charged region

Question 20

Which of the following factors tend to increase membrane fluidity?
A) A greater proportion of unsaturated phospholipids
B) A greater proportion of saturated phospholipids
C) A lower temperature
D) A relatively high protein content in the membrane
E) A greater proportion of relatively large glycolipids compared with lipids having smaller
molecular masses

Answer 20

A) A greater proportion of unsaturated phospholipids