TopHat Questions

Question 1

In order for a hypothesis to be able to be used in science it should be:

Answer 1

It is testable

Question 2

What distinguishes hypotheses from theories?

Answer 2

Hypotheses usually are relatively narrow in scope; theories have broad explanatory power

Question 3

Water is a polar molecule because of the presence of ___________ bonds.

Answer 3

polar covalent

Question 4

Which type of bond must be broken for water to vaporize?

Answer 4

hydrogen bonds

Question 5

Water has an unusually high specific heat. This is because it

Answer 5

has many hydrogen bonds

Question 6

How many molecules of water are needed to completely hydrolyze a polymer that is 11 monomers long?

Answer 6

10

Question 7

There are 20 common amino acids. The distinguishing feature that makes each one unique is:

Answer 7

the nature of the R-group

Question 8

In your small intestine during digestion, pancreatic enzymes break down proteins by _____ reactions into _____.

Answer 8

hydrolysis, amino acids

Question 9

A DNA molecule contains 16% adenine nucleotides. What percentage of thymine nucleotides will be found?

Answer 9

16%

Question 10

What would happen to DNA molecules treated with enzymes that break hydrogen bonds?

Answer 10

The two strands of the double helix would separate

Question 11

If one strand of a DNA molecule has the sequence of bases 5’ATTGCA3’, the other complementary strand would have the sequence:

Answer 11

5’TGCAAT 3’

Question 12

Lactose is a disaccharide composed of glucose and galactose, while maltose is a disaccharide composed of two glucose molecules. People who are lactose intolerant are unable to break down lactose, but they can digest maltose. This validates the point that in carbohydrates _____.

Answer 12

simple changes in structure can cause big changes in function

Question 13

Cellulose absorbs water in your intestines because _____.

Answer 13

like all carbohydrates, it is hydrophilic

Question 14

Why do nutritionists advise you to eat whole grains instead of “sweets” (simple sugars)?

Answer 14

• They contain more fiber
• They take longer to digest
• They provide more energy
• Their breakdown does not cause an
  insulin spike

Question 15

Partially hydrogenated safflower oil compared to naturally occurring safflower oil is _____.

Answer 15

more solid at room temperature because it is more saturated

Question 16

All lipids:

Answer 16

do not dissolve well in water.

Question 17

Compared to tropical fish, arctic fish oils have:

Answer 17

more unsaturated fatty acids.

Question 18

In order for a protein to be an integral membrane protein it would have to be

Answer 18

Both hydrophobic and hydrophilic

Question 19

An animal cell lacking oligosaccharides on the external surface of its plasma membrane would likely be impaired in which function?

Answer 19

cell-cell recognition

Question 20

_____ fatty acids and _____ hydrocarbon chains increase membrane permeability

Answer 20

Unsaturated; short

Question 21

Which of the following would likely move through the lipid bilayer of a plasma membrane most rapidly?

Answer 21

CO2

Question 22

Which of the following statements about osmosis is correct?

Answer 22

The presence of aquaporins (proteins that form water channels in the membrane) should speed up the process of osmosis.

Question 23

The solutions in the arms of a U-tube are separated at the bottom of the tube by a selectively permeable membrane. The membrane is permeable to sodium chloride but not to glucose. Side A is filled with a solution of 0.4 M glucose and 0.5 M sodium chloride (NaCl), and side B is filled with a solution containing 0.8 M glucose and 0.4 M sodium chloride. Initially, the volume in both arms is the same. Refer to the figure to answer the following question. At the beginning of the experiment,

Answer 23

side A is hypotonic to side B.

Question 24

If cells are grown in a medium containing radioactive 32P-labeled phosphate, which of these molecules will be labeled?

Answer 24

both phospholipids and nucleic acids

Question 25

Approximately 32 different monomeric carbohydrate subunits are found in various natural polysaccharides. Proteins are composed of 20 different amino acids. DNA and RNA are each synthesized from four nucleotides.
Among these biological polymers, which has the least structural variety?

Answer 25

DNA