Nucleic Acid Structure and Replication Quiz

Nucleotides are the fundamental units composing nucleic acids, consisting of a sugar, phosphate group, and nitrogenous base.

Thymine is absent in RNA; instead, uracil replaces it as a complementary base to adenine.

Nucleotides consist of a phosphate group, sugar (deoxyribose in DNA), and a nitrogenous base, not ribose sugar.

Hydrogen bonds are responsible for connecting the complementary base pairs (A-T and G-C) in the DNA double helix.

Helicase is the enzyme that unwinds the DNA double helix by breaking the hydrogen bonds between base pairs.

DNA ligase seals the nicks between Okazaki fragments, creating a continuous DNA strand during replication.

DNA polymerase synthesizes the new DNA strand in the 5' to 3' direction.

The origin of replication is a specific site where DNA replication begins, initiating the unwinding of DNA strands.

Primase synthesizes short RNA primers that provide a starting point for DNA synthesis by DNA polymerase.

Topoisomerase alleviates supercoiling stress by cutting and rejoining DNA strands during replication.

Mismatch repair rectifies errors in base pairing that may occur during DNA replication, ensuring fidelity.

Telomerase extends the ends of chromosomes by adding repetitive DNA sequences, known as telomeres, preventing degradation.

The sliding clamp protein stabilizes DNA polymerase on the template strand, facilitating continuous synthesis.