DNA structure review

Front

What is the structure of DNA?

Back

DNA is a double helix composed of two strands of nucleotides, with a sugar-phosphate backbone and nitrogenous bases (adenine, thymine, cytosine, guanine) paired in the center.

Front

What are the four nitrogen bases in DNA?

Back

The four nitrogen bases in DNA are adenine (A), thymine (T), cytosine (C), and guanine (G).

Front

What is the base pairing rule in DNA?

Back

Adenine pairs with thymine (A-T) and cytosine pairs with guanine (C-G).

Front

What is DNA replication?

Back

DNA replication is the process by which a cell makes an exact copy of its DNA, resulting in two identical DNA molecules.

Front

What is the role of DNA polymerase in DNA replication?

Back

DNA polymerase is an enzyme that synthesizes new DNA strands by adding nucleotides complementary to the template strand during replication.

Front

What is the significance of the semi-conservative model of DNA replication?

Back

The semi-conservative model means that each new DNA molecule consists of one original strand and one newly synthesized strand, ensuring genetic continuity.

Front

What is the function of helicase in DNA replication?

Back

Helicase is an enzyme that unwinds and separates the two strands of the DNA double helix during replication.

Front

What is the difference between leading and lagging strands in DNA replication?

Back

The leading strand is synthesized continuously in the direction of the replication fork, while the lagging strand is synthesized in short segments (Okazaki fragments) away from the fork.

Front

What are Okazaki fragments?

Back

Okazaki fragments are short segments of DNA synthesized on the lagging strand during DNA replication.

Front

What is the role of ligase in DNA replication?

Back

DNA ligase is an enzyme that joins Okazaki fragments together on the lagging strand, sealing nicks in the sugar-phosphate backbone.