Question 1

Which of the following is the type of bond between molecules of water in a beaker of water?

Accepted Answer

In a beaker of water, the type of bond between molecules of water is a hydrogen bond. This is because the water molecule is a polar molecule with a positive end (hydrogen) and a negative end (oxygen). The positive hydrogen end of one water molecule is attracted to the negative oxygen end of another water molecule, forming a weak hydrogen bond between them.

Question 2

The antimicrobial drug imidazole inhibits sterol synthesis. This would most likely interfere with

Accepted Answer

Imidazole inhibits sterol synthesis, which is essential for the formation and function of eukaryotic plasma membranes. Therefore, it would interfere with the cell membrane of eukaryotic organisms. It has no effect on bacterial cell walls, prokaryotic plasma membranes, fungal cell walls, or genes.

Question 3

What do genes consist of?

Accepted Answer

Genes consist of nucleic acids, specifically deoxyribonucleic acid (DNA) or ribonucleic acid (RNA), which encode the instructions for building and maintaining an organism.

Question 4

Which of the following is the type of bond holding K+ and I- ions in KI?

Accepted Answer

KI forms an ionic bond because K+ is a metal and I- is a non-metal. The transfer of electrons from K to I creates positively charged K+ and negatively charged I- ions, which are held together by electrostatic attraction.

Question 5

A scientist wants to perform a test that will indicate whether a nucleic acid sample is composed of RNA or DNA. Testing for the presence of which of the following is most appropriate in this situation?

Accepted Answer

Uracil is a nitrogenous base present in RNA but not in DNA. Therefore, if uracil is present in the sample being tested, it indicates that the nucleic acid is RNA.

Question 6

Which type of molecule NEVER contains a phosphate group?

Accepted Answer

Triglycerides are composed of three fatty acid molecules and one glycerol molecule, but they do not contain a phosphate group. Nucleic acids, phospholipids, and ATP all contain phosphate groups.

Question 7

What is the type of bond holding hydrogen and oxygen atoms together in a single H 2O molecule?

Accepted Answer

The bond holding hydrogen and oxygen atoms together in a single H2O molecule is a covalent bond. This is because the hydrogen and oxygen atoms share electrons to form a stable molecule. Ionic bonds involve the transfer of electrons, while hydrogen bonds involve the attraction between a hydrogen atom of one molecule and a highly electronegative atom of another molecule.

Question 8

Which type of molecule contains the alcohol glycerol?

Accepted Answer

Glycerol is a component of phospholipids, which are a type of lipid molecule. Lipids are not included in the choices given, but of the choices given, phospholipids are the only ones that contain glycerol.

Question 9

Which type of molecule contains -NH2 (amino) groups?

Accepted Answer

Proteins contain amino groups (-NH2) as part of their structure, specifically in the amino acids that make up proteins.

Question 10

What is the type of weak bond between the hydrogen of one molecule and the nitrogen of another molecule, where the two donʹt actively share an electron?

Accepted Answer

The weak bond between the hydrogen of one molecule and the nitrogen of another molecule, where the two don't actively share an electron, is a hydrogen bond.

Question 11

Which of the following statements regarding protein structure is FALSE?

Accepted Answer

Tertiary structures are formed from a variety of types of bonds, including covalent, hydrogen, ionic, and hydrophobic interactions.

Question 12

What is the type of strong chemical bond between carbon, hydrogen, and oxygen atoms in a single organic molecule?

Accepted Answer

The strong chemical bond between carbon, hydrogen, and oxygen atoms in a single organic molecule is a covalent bond. This type of bond involves the sharing of electrons between atoms to form a stable molecule. Covalent bonds are typically stronger than hydrogen bonds, which involve weak attractions between partially charged atoms or molecules, and ionic bonds, which involve the transfer of electrons between atoms to form ions that attract one another due to their opposite charges.

Question 13

Figure 2.1
 
-In Figure 2.1, which is an alcohol?

Accepted Answer

The molecule labeled as "c" is an alcohol because it contains a hydroxyl group (OH) attached to a carbon atom. The other molecules do not have a hydroxyl group and therefore are not alcohols.

Question 14

Based upon the valence numbers of the elements magnesium (2) and hydrogen (1), predict how many covalent bonds would form between these atoms to achieve the full complement of electrons in their outermost energy shells.

Accepted Answer

Since magnesium has a valence number of 2, it wants to lose two electrons to achieve a full outer shell. Hydrogen has a valence number of 1, and wants to gain one electron to achieve a full outer shell. Therefore, it will take two hydrogen atoms bonding with one magnesium atom, sharing two electrons each, to achieve a full outer shell. This results in two covalent bonds.

Question 15

Which molecule is composed of a chain of amino acids?

Accepted Answer

Proteins are composed of one or more long chains of amino acids, which are linked together by peptide bonds. Carbohydrates are composed of simple sugars, lipids are composed of fatty acids and glycerol, and nucleic acids are composed of nucleotides.

Question 16

Which of the following statements is FALSE?

Accepted Answer

Water molecules are not formed by hydrolysis. Hydrolysis is a chemical reaction that uses water to break apart molecules. Water molecules are formed through a combination of two hydrogen atoms and one oxygen atom.

Question 17

Structurally, ATP is most like which type of molecule?

Accepted Answer

ATP (adenosine triphosphate) is structurally similar to nucleic acids because it is composed of a nitrogenous base (adenine), a sugar (ribose), and three phosphate groups, components that are also found in the building blocks of DNA and RNA.

Question 18

Which are the primary molecules making up plasma membranes in cells?

Accepted Answer

The answer of Which are the primary molecules making up...

Question 19

Which type of molecule is composed of (CH₂O) units?

Accepted Answer

Carbohydrates are composed of repeating units of (CH₂O), which is the basic formula for monosaccharides, the simplest form of carbohydrates.

Question 20

What is the type of bond between ions in salt?

Accepted Answer

Ionic bond. In salt, the sodium (Na+) and chloride (Cl-) ions are held together by a strong electrostatic attraction. This type of bond is known as an ionic bond.

Quiz 2: Chemical Principles