Question 1

A patient is hyperventilating, causing rapid removal of $CO_2$ from the blood. According to the following equilibrium, what will happen to the blood pH?

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

Accepted Answer

Blood pH will increase, making the blood more basic.

Question 2

Which of the following best describes the function of a buffer in biological systems?

Accepted Answer

A buffer resists changes in pH by reversibly binding or releasing $H^+$ ions.

Question 3

If a person receives an infusion of bicarbonate ($HCO_3^-$) to treat acidosis, which direction will the following equilibrium shift?

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

Accepted Answer

To the left, decreasing $H^+$ concentration.

Question 4

Which of the following is a correct example of a dehydration reaction in biological systems?

Accepted Answer

Linking two monosaccharides to form a disaccharide, releasing $H_2O$.

Question 5

What is the molecular formula of sucrose, formed by joining two glucose molecules ($C_6H_{12}O_6$) via a dehydration reaction?

Accepted Answer

$C_{12}H_{22}O_{11}$

Question 6

Which of the following statements about polysaccharides is TRUE?

Accepted Answer

Cellulose provides structural support in plant cell walls.

Question 7

A person is experiencing metabolic alkalosis (high blood pH). Which of the following would the buffer system do to help restore normal pH?

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

Accepted Answer

Release $H^+$ ions by shifting the equilibrium to the right.

Question 8

Which of the following best explains why hydrocarbons are hydrophobic?

Accepted Answer

They lack significant electronegative atoms, making their bonds nonpolar.

Question 9

Which of the following is NOT a function of carbohydrates in living organisms?

Accepted Answer

Catalyzing chemical reactions

Question 10

During digestion, which type of reaction breaks down macromolecules into their monomers?

Accepted Answer

Hydrolysis reaction

Question 11

Which of the following best describes the structure of a monosaccharide?

Accepted Answer

A short carbon chain (3-7 carbons) with hydrogens and oxygens in a 1:2:1 ratio

Question 12

Which of the following is a correct pairing of a macromolecule and its monomer?

Accepted Answer

Carbohydrate – Monosaccharide

Question 13

Which of the following statements about lipids is TRUE?

Accepted Answer

Lipids are hydrophobic and do not dissolve in water.

Question 14

A solution contains a weak acid and its conjugate base. What property does this solution have?

Accepted Answer

It acts as a buffer, resisting changes in pH.

Question 15

Which of the following best explains why the presence of oxygen in carbohydrates increases their solubility in water?

Accepted Answer

Oxygen atoms allow carbohydrates to form hydrogen bonds with water.

Question 16

Which of the following is a correct example of a polysaccharide and its biological role?

Accepted Answer

Glycogen – energy storage in animals

Question 17

Which of the following best describes the Law of Mass Action as it applies to the carbonic acid buffer system?

Accepted Answer

Adding more $HCO_3^-$ will shift the equilibrium to the left, reducing $H^+$ concentration.

Question 18

Which of the following is a real-life example of a hydrolysis reaction?

Accepted Answer

Digesting starch into glucose in the small intestine

Question 19

Which of the following best explains why chitin is important in biology?

Accepted Answer

It forms the exoskeletons of insects and other arthropods.

Question 20

Which of the following statements about dehydration and hydrolysis reactions is correct?

Accepted Answer

Hydrolysis reactions use water to break bonds in polymers.

General Biology Study Notes: pH, Buffers, and Biomolecules

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