DNA Structure and Replication

Flashcards covering key concepts from the lectures on DNA structure, replication, and transcription.

Criteria for genetic material

The four criteria are: it must store information, be stable, replicate accurately, and have the capacity for change.

Discoverers of DNA structure

Chargaff, Franklin, Watson, and Crick contributed to the discovery of the double-helix structure of DNA.

Semi-conservative replication

DNA replication where each new DNA molecule consists of one old strand and one newly synthesized strand.

Origin of replication

The specific location where DNA replication begins.

Helicase

An enzyme that unwinds the DNA double helix at the replication fork.

Topoisomerase

An enzyme that alleviates the torsional strain ahead of the replication fork by cutting and rejoining DNA strands.

Single-strand binding protein

Stabilizes unwound DNA strands during replication to prevent them from re-annealing.

Primase

An enzyme that synthesizes a short RNA primer to initiate DNA replication.

DNA polymerase

An enzyme that synthesizes new DNA strands by adding nucleotides to a growing chain.

Leading strand

The DNA strand that is synthesized continuously in the direction of the replication fork.

Lagging strand

The DNA strand that is synthesized in short segments, called Okazaki fragments, away from the replication fork.

Telomere replication

The process of replicating the ends of chromosomes, which is crucial for maintaining genomic stability.

Central dogma of molecular biology

Describes the flow of genetic information from DNA to RNA to protein.

Transcription stages

The three stages of transcription are initiation, elongation, and termination.

Role of RNA polymerase

RNA polymerase synthesizes RNA from a DNA template during transcription.

5' cap and 3' polyA tail

Modifications added to eukaryotic mRNAs that protect mRNA from degradation and assist in ribosome binding.

mRNA splicing

The process of removing non-coding regions (introns) from pre-mRNA and joining coding sequences (exons).