Question

"DNA replication does not happen without some help. Which other molecules or types of molecules are needed for DNA replication to occur?"

Answer 1

DNA replication requires many molecules, including DNA polymerase, RNA primase, DNA helicase, and single-strand binding proteins, among others. These molecules collectively form the DNA replicase system, essential for producing two identical daughter DNA molecules from the original DNA strand.

Step-by-step explanation:

DNA replication is a fundamental process in which the DNA is copied in a cell. This complex process requires the assistance of a range of molecules, including enzymes and proteins. The enzyme DNA polymerase, also known as DNA pol, is one of the key players. It adds nucleotides one by one to the growing DNA chain that are complementary to the template strand, needing energy which is derived from nucleoside triphosphates similar to ATP.

Before DNA polymerase can begin synthesis, an RNA primer, made by the enzyme RNA primase, provides the necessary 3'-OH group. In addition, other essential molecules such as DNA helicase are involved in unwinding the DNA double helix, and single-strand binding proteins stabilize the unwound DNA. The process begins at origins of replication, which are specific nucleotide sequences recognized by certain proteins. Altogether, the DNA replicase system or 'replisome' comprises more than 20 enzymes and factors, each contributing to the semi-conservative nature of DNA replication, where each daughter molecule contains one original and one new DNA strand.

Answer 2

Enzymes like DNA polymerase III, HELICASE, Primase, Topoisomerase, ligase.

Step-by-step explanation:

DNA replication is an important process that must occur prior to cell division. DNA content of a cell becomes duplicated in the process. This process, however, cannot occur without some vital elements that play specific roles. These elements are mostly enzymes which includes DNA polymerase III, HELICASE, Primase, Topoisomerase, ligase.

DNA POLYMERASE III is the main enzyme in this process, it adds nucleotides that are complementary to the unwinded DNA strand in order to synthesize its replica.

However, a new complementary DNA strand cannot be synthesized if the original double-stranded DNA does not unwind or separate. This process of unzipping the DNA into a Y-shaped replication fork is done by HELICASE.

DNA polymerase III starts adding nucleotides from the 3' end of the DNA strand. In order to recognize this end on the strand about to be synthesized, PRIMASE synthesizes a short strand of nucleic acid called Primer. This primer provides the DNA polymerase with something to start working on.

TOPOISOMERASE works on the double-stranded DNA prior to formation of replication fork by helicase. It helps prevent the DNA strands from becoming too tight and super coiled in order to make unzipping easy.

LIGASE helps to fill up those gaps in the DNA fragments during the synthesis of a complementary strand.