Question 1

Which of the following best describes an endergonic reaction in biological systems?

Accepted Answer

A reaction that requires an input of energy and forms products with more chemical energy than the reactants.

Question 2

Cellular respiration is an example of which type of chemical reaction?

Accepted Answer

Exergonic reaction

Question 3

Which equation correctly represents the overall reaction for photosynthesis?

Accepted Answer

$$6CO_2 + 6H_2O \rightarrow C_6H_{12}O_6$ + 6O_2$$

Question 4

Which of the following factors will NOT increase the rate of a chemical reaction?

Accepted Answer

Decreasing the concentration of reactants

Question 5

Enzymes are important in biological systems because they:

Accepted Answer

Lower the activation energy required to make or break chemical bonds

Question 6

A patient with Tay-Sachs disease is unable to break down certain lipids in the brain due to a deficiency in which enzyme?

Accepted Answer

Hexosaminidase

Question 7

Which property of water allows it to act as a lubricant between two adjacent surfaces in the body?

Accepted Answer

Ability to reduce friction between surfaces

Question 8

Which of the following statements about acids is TRUE?

Accepted Answer

Acids are electrolytes that ionize and dissociate in water, releasing hydrogen ions.

Question 9

What is the correct formula for calculating pH?

Accepted Answer

$$pH = -\log_{10}[H^+]$$

Question 10

A solution has a hydrogen ion concentration of $$1 	imes 10$$^{-4}$$ M. What is its pH?

Accepted Answer

pH = 4

Question 11

Which of the following best explains how a pH buffer works in blood?

Accepted Answer

It releases $$H^+$$ ions when pH rises and binds $$H^+$$ ions when pH falls.

Question 12

Which of the following is a reversible chemical reaction important for buffering blood pH?

Accepted Answer

$$CO_2 + H_2O$$ \rightleftharpoons H_2CO_3 \rightleftharpoons $$HCO_3^- + H$$^+$$

Question 13

Which of the following would most likely denature an enzyme?

Accepted Answer

A significant increase in temperature above the enzyme's optimal range

Question 14

Which of the following is TRUE regarding bases?

Accepted Answer

Bases ionize in water to release hydroxyl ions ($$OH^-).$$

Question 15

If the concentration of $$H^+$$ ions in a solution increases, what happens to the pH?

Accepted Answer

pH decreases

Question 16

Which of the following is NOT a physiologically important property of water?

Accepted Answer

Acts as a proton donor in chemical reactions

Question 17

Which of the following would most likely slow down an enzyme-catalyzed reaction?

Accepted Answer

Increasing substrate concentration beyond saturation

Question 18

Which of the following is a correct example of an exchange reaction?

Accepted Answer

$$HCl + NaOH \rightarrow H_2O + NaCl$$

Question 19

A patient with phenylketonuria (PKU) is unable to convert phenylalanine to tyrosine due to a deficiency in which enzyme?

Accepted Answer

Phenylalanine hydroxylase

Enzymes, Water, Acids & Bases: Foundations for Anatomy & Physiology

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