Question 1

Which of the following statements about carbon is INCORRECT?

Accepted Answer

Carbon always forms non-polar bonds with other elements.

Question 2

Which functional group is most likely to make a molecule hydrophilic and increase its solubility in water?

Accepted Answer

Hydroxyl group ($$-OH)$$

Question 3

Amino acids are joined together by which type of covalent bond during protein synthesis?

Accepted Answer

Peptide bond

Question 4

Which of the following best describes a dehydration reaction?

Accepted Answer

A reaction that joins monomers to form polymers by removing water.

Question 5

Which functional group is responsible for the acidic properties of amino acids?

Accepted Answer

Carboxyl group ($$-COOH)$$

Question 6

Which of the following is NOT a class of biological macromolecule?

Accepted Answer

Fatty acids

Question 7

Which level of protein structure is primarily stabilized by hydrogen bonds between backbone atoms, forming alpha helices and beta sheets?

Accepted Answer

Secondary structure

Question 8

A mutation causes a polar amino acid to be replaced by a nonpolar amino acid in the active site of an enzyme. What is the most likely consequence?

Accepted Answer

The enzyme's active site may lose its ability to bind polar substrates.

Question 9

Which functional group is found in all nucleotides and is essential for forming the backbone of DNA and RNA?

Accepted Answer

Phosphate group ($$-PO_4$^{2-})$$

Question 10

Which of the following statements about hydrolysis is CORRECT?

Accepted Answer

Hydrolysis breaks polymers into monomers by adding water.

Question 11

Which of the following is a correct description of the structure of an amino acid?

Accepted Answer

A central carbon atom bonded to a carboxyl group, an amino group, a hydrogen atom, and a variable R group.

Question 12

Which type of interaction is responsible for stabilizing the tertiary structure of proteins?

Accepted Answer

Non-covalent interactions between side chains, including hydrogen bonds, ionic bonds, hydrophobic interactions, and disulfide bridges

Question 13

Which of the following is TRUE about the methyl group ($$-CH_3$) in biological molecules?

Accepted Answer

It is nonpolar and often involved in regulating gene expression.

Question 14

Which of the following best explains why carbon can form such a diversity of organic molecules?

Accepted Answer

Carbon has four valence electrons, allowing it to form four covalent bonds with a variety of atoms.

Question 15

Which functional group is most likely to participate in the formation of disulfide bridges in proteins?

Accepted Answer

Sulfhydryl group ($$-SH)$$

Question 16

Which of the following is a function of proteins in living organisms?

Accepted Answer

Catalysis of chemical reactions

Question 17

Which of the following statements correctly compares DNA and RNA?

Accepted Answer

DNA is typically double-stranded, while RNA is usually single-stranded.

Question 18

A scientist is studying a protein that has lost its three-dimensional structure due to high temperature. What is this process called, and what is the likely consequence?

Accepted Answer

Denaturation; the protein will lose its biological function.

Question 19

Which of the following best describes the role of chaperone proteins in cells?

Accepted Answer

They assist newly-formed proteins in folding into their correct three-dimensional shapes.

Carbon and Functional Groups: Foundations of Organic Molecules in Biology

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