DNA Replication

These flashcards cover essential topics related to DNA replication, its mechanisms, key enzymes involved, and the significance of accurate replication.

What is the purpose of DNA replication?

To make a copy of DNA before cell division so that each daughter cell has a complete copy of genetic information.

Describe the Semi-Conservative Model of DNA replication.

In this model, each new DNA double helix consists of one old (parent) strand and one newly synthesized strand.

What enzymes are involved in unwinding DNA during replication?

Helicase unwinds DNA and DNA gyrase prevents tangling upstream from the replication fork.

What is the role of RNA Primase in DNA replication?

RNA Primase adds a short RNA primer to the 3’ end of the template DNA to provide a starting point for DNA polymerase.

How does DNA Polymerase III function during DNA replication?

DNA Polymerase III adds complementary nucleotides to the growing daughter DNA strand.

What are Okazaki fragments?

Short segments of DNA synthesized on the lagging strand during DNA replication.

What is the function of DNA Ligase?

DNA Ligase connects the DNA backbones of Okazaki fragments to complete the lagging strand.

Why is DNA replication considered semi-conservative?

Because each replicated DNA molecule has one old (parental) strand and one new (daughter) strand.

What are the limits of DNA polymerase III?

DNA Polymerase III can only add nucleotides to the 3’ end of an existing DNA strand.

What defines the 'direction' of a DNA molecule?

The anti-parallel strands run in opposite directions, defined as 3’ to 5’ and 5’ to 3’.

List features of the genetic code.

The genetic code is universal, degenerative, contains start and stop codons, and is non-overlapping.

What is a codon?

A sequence of three bases in DNA that codes for one amino acid.

Why is accurate DNA replication important for genetic stability?

Accurate DNA replication ensures offspring inherit genes properly, that new cells receive exact copies, and is necessary for efficient cell function.