Question 1

Which of the following best describes the chemical reaction that forms a peptide bond between two amino acids?

Accepted Answer

A dehydration (condensation) reaction that removes a water molecule to form a covalent bond between amino acids.

Question 2

Refer to the structure of an amino acid. Which group is responsible for the unique properties of each amino acid?

Accepted Answer

The R-group (side chain)

Question 3

Which level of protein structure is characterized by hydrogen bonding between the polypeptide backbone, resulting in alpha helices and beta sheets?

Accepted Answer

Secondary structure

Question 4

A protein is exposed to high heat and loses its function, but its sequence of amino acids remains unchanged. Which level of structure is preserved?

Accepted Answer

Primary structure

Question 5

Which of the following statements about enzyme inhibition is correct?

Accepted Answer

Noncompetitive inhibitors decrease $$V_{max}$$ and do not change $$K_M.$$

Question 6

Which of the following best explains why unsaturated fatty acids increase membrane fluidity?

Accepted Answer

They have double bonds that introduce kinks, preventing tight packing.

Question 7

Which of the following is a correct description of the antiparallel nature of DNA?

Accepted Answer

The 5' end of one strand is aligned with the 3' end of the other strand.

Question 8

Which of the following is evidence supporting the endosymbiotic theory for the origin of mitochondria and chloroplasts?

Accepted Answer

They possess their own circular DNA and reproduce independently of the host cell.

Question 9

Which of the following best describes the function of a kinase enzyme?

Accepted Answer

It adds a phosphate group to a substrate by transferring it from ATP.

Question 10

A scientist is studying a reaction where the addition of more substrate overcomes the effect of an inhibitor. What type of inhibition is this?

Accepted Answer

Competitive inhibition

Question 11

Which of the following best describes the role of phosphodiester bonds in nucleic acids?

Accepted Answer

They link the 5' phosphate group of one nucleotide to the 3' hydroxyl group of another.

Question 12

Which of the following is a function of microRNA (miRNA) in cells?

Accepted Answer

It silences gene expression by base pairing to complementary sequences in mRNA.

Question 13

Which of the following is a correct statement about the Miller-Urey experiment?

Accepted Answer

It showed that amino acids and other organic compounds can form abiotically under early Earth conditions.

Question 14

Which of the following best describes the central dogma of genetics?

Accepted Answer

Information flows from DNA to RNA to proteins.

Question 15

Which of the following is a correct match between a biological macromolecule and its monomer?

Accepted Answer

Carbohydrate – Monosaccharide

Molecules and Fundamentals of Biology: High-Yield Study Notes

Study Guide - Practice Questions