What end are nucleotides added to?
DNA is always synthesized in the 5′-to-3′ direction, meaning that nucleotides are added only to the 3′ end of the growing strand. As shown in Figure 2, the 5′-phosphate group of the new nucleotide binds to the 3′-OH group of the last nucleotide of the growing strand.
How nucleotides are added in DNA replication?
During elongation, an enzyme called DNA polymerase adds DNA nucleotides to the 3 end of the template. Because DNA polymerase can only add new nucleotides at the end of a backbone, a primer sequence, which provides this starting point, is added with complementary RNA nucleotides.
What enzyme is responsible for adding nucleotides to a growing DNA chain during replication?
What is meant by the lagging strand?
The lagging strand is the DNA strand replicated in the 3′ to 5′ direction during DNA replication from a template strand. It is synthesized in fragments. The discontinuous replication results in several short segments which are called Okazaki fragments.
What is lagging strand synthesis?
Overview of lagging strand synthesis Unlike leading strands, lagging strands are synthesized as discrete short DNA fragments, termed ‘Okazaki fragments’ which are later joined to form continuous duplex DNA. Synthesis of an Okazaki fragment begins with a primer RNA-DNA made by polymerase (Pol) α-primase.
What are Okazaki fragments how are they welded together?
How are they welded together? Okazaki fragments are short segments of DNA synthesized away from the replication fork on a template strand during DNA replication. Many such segments are joined together by the enzyme DNA ligase to make up the lagging strand of newly synthesized DNA.
Which base pairs do you think are held more tightly together?
G-C base pairs have 3 hydrogen bonds, while A-T base pairs have two. Therefore, double-stranded DNA with a higher number of G-C base pairs will be more strongly bonded together, more stable, and will have a higher melting temperature. 3. * (1995 2 2) Genes express proteins by transcription followed by translation.
How do you figure out base pairs?
The total number of base pairs is equal to the number of nucleotides in one of the strands (each nucleotide consists of a base pair, a deoxyribose sugar, and a phosphate group).