Question 1

An excess of hydrogen ions in the body fluids can have fatal results because this can

Accepted Answer

Excess hydrogen ions (i.e. low pH) can affect ion movements, disrupt tissue functions, and change the shape of large complex molecules, rendering them nonfunctional. This can have fatal results as it can lead to organ failure and death.

Question 2

In the body, inorganic compounds

Accepted Answer

Inorganic compounds such as bicarbonate ions can function as buffers, helping to maintain a stable pH in the body.

Answer: D 
 Some inorganic compounds, such as calcium phosphate, are important structural components of cells, specifically in bones and teeth.

Therefore, the correct answers are A and D.

Question 3

Carbohydrate molecules

Accepted Answer

Carbohydrate molecules are the body's most readily available source of energy.

Question 4

When two monosaccharides undergo a dehydration synthesis,

Accepted Answer

When two monosaccharides undergo a dehydration synthesis, a disaccharide is formed. This is because a molecule of water is removed from the two monosaccharides, resulting in the formation of a glycosidic bond between the two sugar molecules. This process is commonly seen in the formation of disaccharides such as maltose (glucose + glucose), lactose (glucose + galactose) and sucrose (glucose + fructose). Polysaccharides and starches are formed by the linkage of multiple monosaccharide molecules through repeated dehydration synthesis reactions.

Question 5

A(n) ________ removes hydrogen ions and a(n) ________ releases hydrogen ions.

Accepted Answer

The answer of A(n) ________ removes hydrogen ions and a(n)...

Question 6

Molecules that have the same molecular formula but different structural formulas are called

Accepted Answer

Isomers have the same molecular formula but different structural formulas. Isotopes have the same number of protons but different numbers of neutrons. Isozymes are different forms of enzymes that catalyze the same chemical reaction. Isotypes are different variants of the same gene. Isomoles is not a scientific term.

Question 7

When a small amount of HCl or NaOH is added to a solution of Na₂HPO₄, the pH of the solution barely changes. Based on these observations, all of the following are True concerning the compound Na₂HPO₄, except

Accepted Answer

Na₂HPO₄ is a weak acid and a weak base, so it is able to accept and donate hydrogen ions to some extent. However, it does not directly adsorb excess H⁺ and OH⁻ onto its crystalline structure. This statement is not true, therefore choice C is incorrect. Choices A, B, D and E are all true statements about Na₂HPO₄.

Question 8

An example of an organic substance is

Accepted Answer

Organic substances are those compounds that contain carbon and hydrogen atoms, often in combination with other elements such as oxygen, nitrogen, sulfur, and phosphorus. Sucrose, a common sugar found in many plants, is a classic example of an organic substance. Carbonic acid, sodium chloride, oxygen, and carbon dioxide are all inorganic substances, as they do not contain both carbon and hydrogen.

Question 9

The group of organic compounds containing carbon, hydrogen, and oxygen in a near 1:2:1 ratio is defined as a

Accepted Answer

Carbohydrates are defined as organic compounds containing carbon, hydrogen, and oxygen in a near 1:2:1 ratio. This ratio is commonly represented by the chemical formula (CH2O)n. Carbohydrates include sugars, starches, and fibers, and they serve as a major source of energy for living organisms.

Question 10

The most important metabolic fuel molecule in the body is

Accepted Answer

Glucose is the primary source of energy for the body's cells and is required for a variety of metabolic processes. While other molecules, such as certain amino acids and fatty acids, can also be used for energy, glucose is the most efficient and abundant source. Sucrose, caffeine, protein, and vitamins are all important for various aspects of metabolism and health, but they are not the primary metabolic fuel molecule in the body.

Question 11

Of the list below, which has the highest concentration of hydroxide ions?

Accepted Answer

pH 14 has the highest concentration of hydroxide ions because as pH increases, the concentration of hydroxide ions also increases with a decrease in the concentration of hydrogen ions. At pH 14, the concentration of hydroxide ions is 10^-14 M, which is the highest concentration of hydroxide ions among the given options.

Question 12

Carbohydrates, lipids, and proteins are classified as

Accepted Answer

Carbohydrates, lipids, and proteins are all composed of carbon and are therefore classified as organic molecules.

Question 13

Which has the greater concentration of hydrogen ions, a substance with a pH of 5 or a substance with a pH of 4?

Accepted Answer

The lower the pH value, the higher the concentration of hydrogen ions. Therefore, a substance with a pH of 4 has a greater concentration of hydrogen ions than a substance with a pH of 5.

Question 14

Which of the following is the symbol for an amino group?

Accepted Answer

The symbol for an amino group is -NH₂. Option A (-COOH) represents a carboxyl group, option B (-PO₃) represents a phosphate group, option D (-AMO) is not a valid chemical group, and option E (-OH) represents a hydroxyl group.

Question 15

A functional group is best described as reoccurring clusters of

Accepted Answer

A functional group is a specific group of atoms within a molecule that greatly influences the chemical properties of the molecule. This is because functional groups have specific chemical and physical properties that give the molecule its characteristic behavior. Therefore, option B is the best choice as it accurately describes the role of functional groups in molecules.

Question 16

Which pH is closest to normal blood pH?

Accepted Answer

Normal blood pH ranges from 7.35-7.45, therefore pH 7 is the closest option.

Question 17

Of the following choices, the pH of the least acidic solution is

Accepted Answer

The pH scale ranges from 0 (most acidic) to 14 (most basic). A pH of 7 is neutral. Therefore, the solution with a pH of 12 is the least acidic and is slightly basic.

Question 18

A polysaccharide that is formed in liver and muscle cells to store glucose is

Accepted Answer

Glycogen is the polysaccharide formed in the liver and muscle cells to store glucose. Lactose is a disaccharide found in milk, cellulose is a structural polysaccharide found in plants, sucrose is a disaccharide made from glucose and fructose, and fructose is a monosaccharide found in fruit.

Question 19

When placed in water, an inorganic compound dissociates 99 percent, forming hydrogen ions and anions. This compound would be

Accepted Answer

When an inorganic compound dissociates 99 percent in water, it forms a high concentration of hydrogen ions, indicating a strong acidity.

Question 20

Fructose

Accepted Answer

Fructose is a hexose, meaning it has six carbon atoms in its structure, making it an isomer of glucose. It is commonly found in fruits, as well as in many sweeteners and processed foods. Therefore, all of the above options are correct.

Quiz 2: Chemical Level of Organization