Question 1

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

Accepted Answer

A reaction that requires an input of energy, such as photosynthesis.

Question 2

During cellular respiration, glucose is broken down in an exergonic reaction. Which of the following equations correctly represents this process?

Accepted Answer

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

Question 3

Which factor would most likely increase the rate of a chemical reaction in a cell?

Accepted Answer

Adding a catalyst such as an enzyme.

Question 4

A patient with Tay-Sachs disease lacks the enzyme hexosaminidase. What is the physiological consequence of this deficiency?

Accepted Answer

Accumulation of gangliosides around neurons, leading to neurodegeneration.

Question 5

Which property of water allows it to help regulate body temperature during exercise?

Accepted Answer

Water's high heat capacity, allowing it to absorb heat without significant temperature change.

Question 6

Which of the following best explains why enzymes are specific to their substrates?

Accepted Answer

Enzymes have unique active sites that bind only specific substrates.

Question 7

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

Accepted Answer

$$4$$

Question 8

Which of the following statements about acids is correct?

Accepted Answer

Acids are proton donors and increase the concentration of $$H^+ in $$solution.

Question 9

What is the main function of a buffer in blood?

Accepted Answer

To prevent rapid changes in pH by releasing or binding $$H^+$$ ions.

Question 10

If the pH of a solution changes from 7 to 5, what happens to the hydrogen ion concentration?

Accepted Answer

It increases by a factor of 100.

Question 11

Which of the following best describes the effect of temperature on enzyme activity?

Accepted Answer

Enzyme activity increases with temperature up to an optimal point, then decreases due to denaturation.

Question 12

Which of the following is an example of a reversible chemical reaction important in physiology?

Accepted Answer

$$CO_2 + H_2O$$ \rightleftharpoons H_2CO_3$$

Question 13

A patient is diagnosed with phenylketonuria (PKU). Which enzyme is deficient and what is the consequence if untreated?

Accepted Answer

Phenylalanine hydroxylase; buildup of phenylalanine causing seizures and intellectual disability.

Question 14

Which property of water is most important for its role as a solvent in the body?

Accepted Answer

Water's ability to form hydration spheres around ions and polar molecules.

Question 15

Which of the following best explains why increasing substrate concentration increases enzyme activity only up to a certain point?

Accepted Answer

All enzyme active sites become occupied, so the reaction rate plateaus.

Question 16

Which of the following is a correct statement about bases?

Accepted Answer

Bases are proton acceptors that increase $$OH^-$$ concentration.

Question 17

A buffer system in blood involves carbonic acid ($$H_2CO_3) $$and bicarbonate ($$HCO_3$$^-$$). What happens when blood pH falls (becomes more acidic)?

Accepted Answer

$$HCO_3$$^-$$ binds H$$^+$$ to form H_2CO_3$, helping to raise pH.

Question 18

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

Accepted Answer

Dissolves hydrophobic molecules easily.

Question 19

Which of the following best describes the relationship between $$[H^+]$$ and pH?

Accepted Answer

As $$[H^+]$$ increases, pH decreases.

Question 20

A cleaning agent is found to have a pH of 12. Which of the following best describes this substance?

Accepted Answer

It is a strong base with high $$[OH^-]$$ concentration.

Chapter Two pt. 2

Study Guide - Practice Questions

Study Guide - Flashcards