Chemical Components of DNA

What three components make up a DNA nucleotide

A deoxyribose sugar, phosphate group, and nitrogenous base.

What sugar is found in DNA

Deoxyribose, a five-carbon sugar.

What are the four nitrogenous bases in DNA

Adenine (A), thymine (T), guanine (G), and cytosine (C).

Which nitrogenous bases are purines

Adenine and guanine; both have two rings.

Which nitrogenous bases are pyrimidines

Cytosine and thymine; both have one ring.

What is the difference between a purine and a pyrimidine

Purines have two fused rings, while pyrimidines have one ring.

What is the role of the phosphate group in DNA

It connects adjacent sugars through phosphodiester bonds to form the sugar-phosphate backbone.

What is the role of deoxyribose in DNA

It forms part of the backbone and attaches to the phosphate group and nitrogenous base.

What is the role of nitrogenous bases in DNA

Their sequence stores genetic information, and complementary pairing enables accurate copying.

What is a nucleoside

A nitrogenous base attached to a sugar, without a phosphate group.

What is a phosphodiester bond

A covalent bond connecting the 3′ hydroxyl of one nucleotide's sugar to the 5′ phosphate of the next nucleotide.

What is the difference between a phosphodiester bond and a hydrogen bond in DNA

Phosphodiester bonds join nucleotides within a strand; hydrogen bonds connect complementary bases between strands.