Question 1

Which of the following best describes an isomer?

Accepted Answer

Molecules with the same molecular formula but different arrangements of atoms.

Question 2

Which functional group is characterized by the formula $-COOH$ and acts as an acid in biological systems?

Accepted Answer

Carboxyl group

Question 3

A molecule with a $-SH$ group is classified as which type of functional group?

Accepted Answer

Sulfhydryl group

Question 4

Which of the following is true about enantiomers?

Accepted Answer

They are non-superimposable mirror images of each other.

Question 5

Which reaction joins two monomers together and produces water as a byproduct?

Accepted Answer

Condensation (dehydration) reaction

Question 6

Which of the following best describes a monosaccharide?

Accepted Answer

A simple sugar that cannot be hydrolyzed into smaller carbohydrates.

Question 7

Which of the following is a correct structural difference between saturated and unsaturated fatty acids?

Accepted Answer

Saturated fatty acids have no double bonds between carbon atoms, while unsaturated fatty acids have one or more double bonds.

Question 8

Which of the following is NOT a correct pairing of a functional group and its formula?

Accepted Answer

Hydroxyl group: $-COOH$

Question 9

Which level of protein structure is defined by the sequence of amino acids in a polypeptide chain?

Accepted Answer

Primary structure

Question 10

Which of the following bonds is responsible for holding together the secondary structure of proteins, such as alpha helices and beta sheets?

Accepted Answer

Hydrogen bonds

Question 11

Which of the following best describes a phospholipid's structure?

Accepted Answer

A molecule with a hydrophilic phosphate head and two hydrophobic fatty acid tails.

Question 12

Which of the following statements about starch and cellulose is correct?

Accepted Answer

Both are polymers of glucose, but cellulose has beta-1,4 glycosidic bonds while starch has alpha-1,4 glycosidic bonds.

Question 13

Which of the following is true about the quaternary structure of proteins?

Accepted Answer

It involves the association of multiple polypeptide chains into a functional protein complex.

Question 14

Which process breaks down polymers into monomers by adding water?

Accepted Answer

Hydrolysis

Question 15

Which of the following amino acids does NOT have a chiral carbon?

Accepted Answer

Glycine

Question 16

Which of the following best describes a disulfide bridge in proteins?

Accepted Answer

A covalent bond formed between two cysteine residues via their sulfhydryl groups.

Question 17

Which of the following is a correct description of a triglyceride?

Accepted Answer

A molecule composed of three fatty acids esterified to a glycerol backbone.

Question 18

Which environmental condition is most likely to cause protein denaturation?

Accepted Answer

Extreme pH or high temperature

Question 19

Which of the following is a correct example of a monosaccharide?

Accepted Answer

Glucose

Question 20

Which of the following best explains why phospholipids form bilayers in water?

Accepted Answer

Their hydrophilic heads interact with water while their hydrophobic tails avoid water.

Ch 3 review

Study Guide - Practice Questions