The leading strand is synthesized continuously, as shown in Figure 5. In contrast, the lagging strand is synthesized in small, separate fragments that are eventually joined together to form a complete, newly copied strand.
How do stabilizing proteins work on the DNA?
How do stabilizing proteins work on the DNA? They bind to the single-stranded DNA. They bind to the double-stranded DNA.
How do the repressor proteins block the transcription of the structural genes?
A DNA-binding repressor blocks the attachment of RNA polymerase to the promoter, thus preventing transcription of the genes into messenger RNA. An RNA-binding repressor binds to the mRNA and prevents translation of the mRNA into protein. This blocking or reducing of expression is called repression.
What is the function of the parental DNA in replication?
An organism must copy its DNA to pass genetic information to its offspring. What is the function of the parental DNA in replication? It gives the cell two complete copies of the DNA. It serves as the template for DNA replication.
What enzyme removes primers?
Removal of RNA primers and joining of Okazaki fragments. Because of its 5′ to 3′ exonuclease activity, DNA polymerase I removes RNA primers and fills the gaps between Okazaki fragments with DNA.
What is a daughter strand?
Daughter strand
Refers to the newly synthesized strand of DNA that is copied via the addition of complementary nucleotides from one strand of pre-existing DNA during DNA replication.
What is the function of primers positioned on the DNA strand by primase?
Primase functions by synthesizing short RNA sequences that are complementary to a single-stranded piece of DNA, which serves as its template. From the Internet: A primer is a short single strand of RNA or DNA (generally about 18-22 bases) that serves as a starting point for DNA synthesis.
What are the features that contribute to the stability and the ability of the DNA to replicate faithfully?
There are 3 H bonds between Guanine and Cytosine and 2 between Adenine and Thymine. As well as this there are hydrogen bonds between the bases and surrounding water molecules, and this combined with the even stronger phosphodiester bonds in the sugar phosphate backbone make DNA very stable.
Does DNA ligase remove primers?
DNA ligase I is responsible for joining Okazaki fragments together to form a continuous lagging strand. Because DNA ligase I is unable to join DNA to RNA, the RNA-DNA primers must be removed from each Okazaki fragment to complete lagging strand DNA synthesis and maintain genomic stability.
When an inducer molecule attaches to the repressor protein What happens to the repressor protein?
An inducer functions in two ways; namely: By disabling repressors. The gene is expressed because an inducer binds to the repressor. The binding of the inducer to the repressor prevents the repressor from binding to the operator.
What are repressible operons?
A repressible operon is one that is usually on but which can be repressed in the presence of a repressor molecule. The repressor binds to the operator in such a way that the movement or binding of RNA polymerase is blocked and transcription cannot proceed.
What is the inducer molecule in the lac operon What is the inducer molecule in the lac operon?
The inducer molecule, allo-lactose, signifies the presence of lactose. Allo-lactose binds to LacI and prevents it from repressing transcription of lacZYA, thus the operon is derepressed.
Which enzyme is responsible for assembling the DNA during replication?
The DNA polymerases are enzymes that create DNA molecules by assembling nucleotides, the building blocks of DNA. These enzymes are essential to DNA replication and usually work in pairs to create two identical DNA strands from one original DNA molecule.
What is the result of DNA ligase’s action?
What is the result of DNA ligase’s action? DNA is broken up at specific sites. DNA translation occurs.
How does the DNA polymerase and DNA ligase function in DNA replication?
On the leading strand, DNA is synthesized continuously, whereas on the lagging strand, DNA is synthesized in short stretches called Okazaki fragments. DNA polymerase I replaces the RNA primer with DNA. DNA ligase seals the gaps between the Okazaki fragments, joining the fragments into a single DNA molecule.
How do primers work?
Upon being struck with sufficient force generated by the firing pin, or electrically ignited, primers react chemically to produce heat, which gets transferred to the main propellant charge and ignites it, and this, in turn, propels the projectile.
What do primers do biology?
A primer is a short nucleic acid sequence that provides a starting point for DNA synthesis. In living organisms, primers are short strands of RNA. A primer must be synthesized by an enzyme called primase, which is a type of RNA polymerase, before DNA replication can occur.
What is DNA polymerase function?
DNA polymerase (DNAP) is a type of enzyme that is responsible for forming new copies of DNA, in the form of nucleic acid molecules.
