Nucleotides and Carbohydrate Structures

What was the original definition of organic chemistry?

• The study of molecules found only in living organisms.

• The study of carbon-containing compounds.

• The study of human-made chemicals.

• The study of all chemical reactions.

A carbohydrate with five carbon atoms is called a what?

• Triose

• Tetrose

• Pentose

• Hexose

Carbohydrates are classified based on their functional groups as either:

• Acids or bases

• Aldehydes or ketones

• Alkanes or alkenes

• Alcohols or ethers

In a Fischer projection of a sugar, if the hydroxyl (OH) group on the bottom-most chiral carbon is on the right, what is it called?

• An L-sugar

• A D-sugar

• A ketose

• An aldose

What type of ring structure does fructose usually form?

• A six-membered pyranose ring.

• A five-membered furanose ring.

• A four-membered cyclobutane ring.

• A seven-membered cycloheptane ring.

What is the relationship between D-glucose and L-glucose?

• They are identical molecules.

• They are isomers with different chemical formulas.

• They are mirror images of each other.

• They are different types of sugars with no relation.

What three main parts make up a nucleotide?

• A nitrogenous base, a sugar, and a phosphate group.

• An amino acid, a fatty acid, and a glycerol.

• A pyrimidine, a purine, and a deoxyribose.

• A protein, a lipid, and a carbohydrate.

Which nitrogenous base is found in RNA but not in DNA?

• Thymine

• Cytosine

• Uracil

• Adenine