RELAY

Which of the following is NOT an organic molecule?

• Carbohydrate

• Lipid

• Nucleic acid

• Sodium chloride

Answer explanation

Organic molecules are molecules that contain carbon atoms bonded to hydrogen atoms, as well as other elements such as oxygen, nitrogen, and sulfur. Sodium chloride is an inorganic molecule, consisting of sodium and chloride ions.

Which of the following is NOT a type of metabolic pathway?

• Anabolic

• Catabolic

• Amphibolic

• Neurologic

Answer explanation

Neurologic is not a type of metabolic pathway. Anabolic pathways build complex molecules from simpler ones, while catabolic pathways break down complex molecules into simpler ones. Amphibolic pathways can function as both anabolic and catabolic pathways.

What is the molecule that cells use to store and transfer energy?

• ATP

• ADP

• AMP

• GTP

Answer explanation

ATP, or adenosine triphosphate, is the molecule that cells use to store and transfer energy. It is synthesized during cellular respiration and is used for various cellular processes that require energy, such as muscle contraction and biosynthesis.

Which of the following is an example of an anabolic pathway?

•  Glycolysis

• Photosynthesis

• Citric acid cycle

• Electron transport chain

Answer explanation

Photosynthesis is an anabolic pathway that uses energy from sunlight to synthesize complex organic molecules, such as glucose, from simpler inorganic molecules, such as carbon dioxide and water. Glycolysis, citric acid cycle, and electron transport chain are catabolic pathways that break down complex organic molecules to produce energy.

Which of the following is TRUE for an oxidizing agent?

• It is reduced in a redox reaction

• It causes the reduction of another species

• It donates electrons to another species

• It has a high reduction potential

Answer explanation

An oxidizing agent is a species that causes another species to be oxidized (lose electrons) in a redox reaction.

As a result, the oxidizing agent itself is reduced (gains electrons) in the reaction.

Which of the following is an example of a redox reaction?

• NaCl + H2O → NaOH + HCl

• H2O2 → H2O + O2

• NH3 + HCl → NH4Cl

• CaCO3 → CaO + CO2

Answer explanation

In this reaction, hydrogen peroxide (H2O2) is decomposed into water (H2O) and oxygen gas (O2). This is a redox reaction because hydrogen peroxide is oxidized (losing electrons) to form water, while oxygen is reduced (gaining electrons) to form oxygen gas.

Which of the following is the oxidizing agent in the following redox reaction?

Fe + CuSO4 → FeSO4 + Cu

• Fe

• CuSO4

• FeSO4

• Cu

Answer explanation

In this reaction, iron (Fe) is oxidized to iron (II) ions (FeSO4), while copper (II) ions (CuSO4) are reduced to copper (Cu).

Therefore, copper (II) ions are the oxidizing agent, because they cause the oxidation of iron to iron (II) ions.

Which of the following is the reducing agent in the following redox reaction?

Cu + 2Ag+ → Cu2+ + 2Ag

• Cu

• Ag+

• Cu2+

• Ag

Answer explanation

In this reaction, copper (Cu) is oxidized to copper (II) ions (Cu2+), while silver ions (Ag+) are reduced to silver (Ag).

Therefore, copper is the reducing agent, because it causes the reduction of silver ions to silver.

What is a redox reaction?

• A reaction that releases energy in the form of heat

• A reaction that forms a new substance

• A reaction that involves a transfer of electrons

• A reaction that produces a gas

Answer explanation

A redox reaction is a chemical reaction that involves a transfer of electrons between two species.

The species that loses electrons is said to be oxidized, while the species that gains electrons is said to be reduced.

What does pH measure?

• The concentration of hydrogen ions in a solution

• The concentration of hydroxide ions in a solution

• The concentration of both hydrogen and hydroxide ions in a solution

• The temperature of a solution

Answer explanation

pH measures the acidity or basicity of a solution by determining the concentration of hydrogen ions (H+) in the solution.

The more hydrogen ions in the solution, the more acidic the solution is.