AP Bio Functional Groups Quiz
Questions: 16 · 10 minutes
1. Which functional group consists of an oxygen atom bonded to a hydrogen atom and commonly increases a molecule’s ability to interact with water?
Hydroxyl group
Carbonyl group
Methyl group
Sulfhydryl group
2. A chemical modification changes gene expression without changing the DNA base sequence by attaching a small nonpolar group to DNA. Which group was most likely added?
Carboxyl group
Methyl group
Sulfhydryl group
Phosphate group
3. The structure CH₃–CO–CH₃ contains a carbonyl carbon bonded to two other carbon atoms. What kind of compound is it?
A ketone
An aldehyde
A carboxylic acid
An amine
4. Which structural feature correctly distinguishes an aldehyde from a ketone?
An aldehyde has an amino group, whereas a ketone has a carbonyl group.
An aldehyde has a terminal carbonyl bonded to a hydrogen, whereas a ketone has a carbonyl within the carbon skeleton.
An aldehyde is always charged, whereas a ketone is always uncharged.
An aldehyde has two oxygen atoms, whereas a ketone has one oxygen atom.
5. A group written as –NH₂ gains H⁺ and becomes –NH₃⁺. Which functional group underwent this change?
Hydroxyl group
Carboxyl group
Amino group
Carbonyl group
6. A molecule has a carbonyl group located within its carbon skeleton rather than at the end. How is the molecule classified based on that arrangement?
An aldehyde
A carboxylic acid
A ketone
An amine
7. Which functional group can act as a base by accepting a hydrogen ion and becoming positively charged?
Methyl group
Carbonyl group
Carboxyl group
Amino group
8. In a phospholipid, which functional group makes an important contribution to the hydrophilic character and charge of the head region?
Sulfhydryl group
Methyl group
Phosphate group
Carbonyl group
9. Which functional group contains both a carbonyl and a hydroxyl attached to the same carbon atom?
Carboxyl group
Amino group
Phosphate group
Sulfhydryl group
10. Two cysteine side chains are oxidized and form a covalent cross-link that helps stabilize a protein’s three-dimensional shape. Which group enabled that cross-link?
Methyl group
Hydroxyl group
Sulfhydryl group
Phosphate group
11. Adding which functional group to an organic molecule most directly tends to contribute negative charge and alter the molecule’s interactions with other substances?
Methyl group
Hydroxyl group
Carbonyl group
Phosphate group
12. A researcher wants to disrupt disulfide bridges in a protein without breaking its peptide bonds. Which group on cysteine residues is directly involved in those bridges?
Sulfhydryl group
Hydroxyl group
Carbonyl group
Phosphate group
13. An amino acid side chain contains –COOH and can lose a hydrogen ion to become –COO⁻. Which functional group is responsible for this behavior?
Amino group
Sulfhydryl group
Methyl group
Carboxyl group
14. During formation of a glucose ring from open-chain glucose, an internal hydroxyl group attacks which functional group in the same molecule?
Phosphate group
Carbonyl group
Sulfhydryl group
Methyl group
15. Ethanol mixes with water much more readily than ethane does. Which feature of ethanol best explains this difference?
Its sulfhydryl group gives the molecule a permanent negative charge.
Its methyl group releases hydrogen ions into water.
Its carbonyl group forms ionic bonds with water.
Its hydroxyl group can form hydrogen bonds with water.
16. When ATP is converted to ADP and inorganic phosphate, which type of functional group is directly removed from ATP?
Carbonyl group
Phosphate group
Amino group
Carboxyl group