Question 1

Which of the following functional groups is responsible for the acidic properties of amino acids and is directly involved in the formation of peptide bonds?

Accepted Answer

Carboxyl group $(-\mathrm{COOH})$

Question 2

A biochemist is studying a molecule that contains a carbon atom double-bonded to an oxygen atom and single-bonded to another oxygen atom, which is also bonded to a hydrogen atom. Which functional group is present in this molecule?

Accepted Answer

Carboxyl group $(-\mathrm{COOH})$

Question 3

Which of the following best describes the process of dehydration synthesis in the formation of biological polymers?

Accepted Answer

A water molecule is removed to form a covalent bond between monomers.

Question 4

Which of the following statements about cellulose is correct?

Accepted Answer

Cellulose is a linear unbranched polymer of glucose that reinforces plant cell walls.

Question 5

A mutation causes a change in the primary structure of a protein. Which of the following levels of protein structure is LEAST likely to be directly affected by this mutation?

Accepted Answer

Quaternary structure (if the protein is a monomer)

Question 6

Which of the following best explains why phospholipids are essential components of cell membranes?

Accepted Answer

They have both hydrophilic and hydrophobic regions, allowing them to form bilayers in aqueous environments.

Question 7

Which of the following is a correct pairing of a disaccharide and its monomers?

Accepted Answer

Lactose: Glucose + Galactose

Question 8

A scientist discovers a molecule with a phosphate group, a five-carbon sugar, and a nitrogenous base. This molecule is most likely a:

Accepted Answer

Nucleotide

Question 9

Which of the following statements about the secondary structure of proteins is TRUE?

Accepted Answer

It involves hydrogen bonding between the backbone atoms of the polypeptide chain.

Question 10

Which functional group is most likely to make a molecule more hydrophobic?

Accepted Answer

Methyl group $(-\mathrm{CH}_3)$

Question 11

Which of the following best describes the role of glycogen in animals?

Accepted Answer

It is a storage polysaccharide found in the liver and muscle.

Question 12

A protein is exposed to high heat and loses its three-dimensional structure but retains its primary sequence. This process is called:

Accepted Answer

Denaturation

Question 13

Which of the following statements about lipids is correct?

Accepted Answer

Lipids are a diverse group of hydrophobic molecules that include fats, phospholipids, and steroids.

Question 14

Which of the following is a correct description of a peptide bond?

Accepted Answer

A covalent bond formed between the carboxyl group of one amino acid and the amino group of another.

Question 15

Which of the following best explains why humans cannot digest cellulose?

Accepted Answer

Humans lack the enzyme to hydrolyze the specific linkage in cellulose.

Question 16

Which of the following is NOT a function of proteins in living organisms?

Accepted Answer

Storing genetic information

Question 17

A molecule contains a sulfhydryl group $(-\mathrm{SH})$. Which of the following is a likely role for this group in a protein?

Accepted Answer

Forming disulfide bridges that stabilize tertiary structure

Question 18

Which of the following best describes the difference between starch and cellulose?

Accepted Answer

Starch is a storage polysaccharide in plants, while cellulose is a structural polysaccharide.

Question 19

Which of the following statements about nucleic acids is TRUE?

Accepted Answer

Nucleic acids store and transmit genetic information.

Question 20

A researcher is analyzing a macromolecule and finds that it contains a repeating backbone of sugar and phosphate groups, with nitrogenous bases attached. This macromolecule is most likely:

Accepted Answer

A nucleic acid

Study Notes: Biological Molecules in General Biology

Study Guide - Practice Questions

Study Guide - Flashcards