Which of the following substances is responsible for donating H+ ions to act as a buffer when blood pH rises?

A. Carbon dioxide

B. Carbonic acid

C. Oxygen

D. Carbon monoxide

Answer Explanation:

A buffer is a solution that can resist changes in pH when small amounts of acid or base are added. In the human body, blood is an important buffer that helps maintain a stable pH of about 7.4. One of the main components of the blood buffer system is the bicarbonate buffer, which involves the equilibrium between carbon dioxide (CO2), carbonic acid (H2CO3), and bicarbonate ions (HCO3-). When blood pH rises, meaning it becomes more basic, the bicarbonate buffer can donate H+ ions to lower the pH and restore the balance. The substance that donates H+ ions in this case is carbonic acid, which dissociates into H+ and HCO3-. Therefore,

Therefore, the Correct Answer is B.

Q #1: Which of the following microorganisms lack their own metabolic pathways and can only reproduce inside of a host cell?

A. Viruses

B. Bacteria

C. Helminths

D. Protozoa

Answer Explanation

Among the four types of microorganisms listed, only viruses lack their own metabolic pathways and can only reproduce inside of a host cell. Viruses are considered to be obligate intracellular parasites, meaning that they depend on another living cell for their survival and replication. Bacteria, helminths, and protozoa, on the other hand, are able to metabolize nutrients and energy from their surroundings and can reproduce independently of a host cell.
Q #2: Which of the following indicates the function of sodium bicarbonate released by the pancreas?

A. Sodium bicarbonate inhibits peristalsis.

B. Sodium bicarbonate stimulates the pyloric sphincter.

C. Sodium bicarbonate is a protease that digests carbohydrates.

D. Sodium bicarbonate neutralizes the acidity of chyme.

Answer Explanation

The pancreas releases sodium bicarbonate into the duodenum, the first part of the small intestine. The main function of sodium bicarbonate is to neutralize the acidity of chyme, the semi-digested food that comes from the stomach. By doing so, sodium bicarbonate creates a more alkaline environment that is suitable for the action of pancreatic enzymes. Sodium bicarbonate does not affect peristalsis, the rhythmic contraction of the intestinal muscles, nor does it stimulate the pyloric sphincter, the valve that controls the passage of food from the stomach to the duodenum. Sodium bicarbonate is not a protease, an enzyme that digests proteins, nor does it digest carbohydrates.
Q #3: Which of the following summarizes a change that takes place as a solid turns to a liquid?

A. Particles become less ordered.

B. Intermolecular forces between particles become stronger.

C. Particles move closer together.

D. Particles have a decrease in mobility.

Answer Explanation

When a solid turns into a liquid during the process of melting, the particles within the solid gain enough energy to overcome the attractive forces holding them in a fixed arrangement. As a result, the particles become less ordered and more mobile, transitioning from a rigid structure to a more fluid state.

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Which of the following substances is responsible for donating H+ ions to act as a buffer when blood pH rises?

More Questions on TEAS 7 Science

Q #1: Which of the following microorganisms lack their own metabolic pathways and can only reproduce inside of a host cell?

Answer Explanation

Q #2: Which of the following indicates the function of sodium bicarbonate released by the pancreas?

Answer Explanation

Q #3: Which of the following summarizes a change that takes place as a solid turns to a liquid?

Answer Explanation

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