Weekly Quiz 2

Question 1

The inside of a cell contains several buffers. These buffers help ensure that

Answer 1

pH inside the cell remains stable when extracellular pH changes

Question 2

Carbohydrates contain

Answer 2

Oxygen
Carbon
Hydrogen

Question 2

Sources of chemical potential energy in the body include

Answer 2

Carbohydrate
Protein
Fat

Question 3

Which of the following usually dissolves well in water?

Answer 3

Carbohydrates
Ions

Question 4

Pumping sodium against its electrochemical gradient is

Answer 4

Endergonic

Question 5

Which of the following chemical reactions would occur most rapidly without an enzyme?

Answer 5

An exergonic chemical reaction in a very hot environment

Question 6

Imagine a solution containing only water, sodium, and glucose. If a voltage is applied to the solution, glucose would move

Answer 6

There would be no net movement of glucose

Question 7

Enzymes

Answer 7

Lower the activation energy required for a chemical reaction to occur

Question 8

Hydrophobic lipid tails contain

Answer 8

C-C and C-H bonds

Question 9

Does a solution that contains only water and glucose conduct electricity?

Answer 9

No

Question 10

Which of the following reactions can occur rapidly in the presence of an enzyme catalyst?

Answer 10

• An exergonic chemical in the presence of ATP
• An exergonic chemical reaction without ATP or any other energy source
• An endergonic chemical reaction in the presence of ATP

Question 11

A solution that conducts electricity must contain

Answer 11

Ions

Question 12

Pepsin is an enzyme that breaks down protein in the stomach. The pH of the stomach can be as low as 1-2. In order for pepsin to break down protein in a solution with a starting pH of 7.4, you must

Answer 12

Add acid

Question 13

Which of the following bonds are polar (“polar” referring to polar enough to dissolve in water)?

Answer 13

O-H

Question 14

The primary purpose of a buffer is to

Answer 14

Maintain the hydrogen ion concentration of a solution

Question 15

Ions moving down their electrochemical gradient

Answer 15

Release potential energy

Question 16

Imagine a beaker of water into which we place two drops of red food coloring and one drop of blue food coloring. The drops land in different places on the surface of the water. The concentration gradient acting on the red molecules would be

Answer 16

Stronger than on the blue molecules, but in a different direction

Question 17

How would adding acid to a non-buffered solution be most likely to affect protein structure?

Answer 17

Adding acid would disrupt the secondary and tertiary structure of the protein

Question 18

Water is

Answer 18

Hydrophilic
Polar

Question 19

If a chemical binds to a protein, which of the following would you expect to occur?

Answer 19

The protein would change shape
The protein would change function