In which aspect of DNA structure are hydrogen bonds important?

In which aspect of DNA structure are hydrogen bonds important?

Terms in this set (6) In which aspect of DNA structure are hydrogen bonds important? The arrangement of atoms allows precise hydrogen bonding.

What is the pairing pattern of the bases in nucleic acids?

The rules of base pairing (or nucleotide pairing) are: A with T: the purine adenine (A) always pairs with the pyrimidine thymine (T) C with G: the pyrimidine cytosine (C) always pairs with the purine guanine (G)

Which of the following base pairs requires the most energy to break apart?

Explanation: The guanine and cytosine base pairing forms 3 hydrogen bonds. Both adenine and thymine form only 2 hydrogen bonds. Thus the G-C base pair has the strongest interactions, and requires the most amount of energy to break.

What is meant by the description antiparallel regarding the two strands?

What is meant by the description “antiparallel” regarding the two strands that make up the DNA double helix? The 5′ to 3′ direction of one strand runs counter to the 5′ to 3′ direction of the other strand.

What is the function of DNA polymerase III?

The main function of the third polymerase, Pol III, is duplication of the chromosomal DNA, while other DNA polymerases are involved mostly in DNA repair and translesion DNA synthesis. Together with a DNA helicase and a primase, Pol III HE participates in the replicative apparatus that acts at the replication fork.

What is meant by the description antiparallel regarding the two strands of nucleic acids that make up DNA group of answer choices?

What is meant by the description “antiparallel” regarding the strands that make up DNA? The 5′ to 3′ direction of one strand runs counter to the 5′ to 3′ direction of the other strand. Cytosine makes up 42% of the nucleotides in a sample of DNA from an organism.

What does 5 mean in DNA?

Each end of DNA molecule has a number. One end is referred to as 5′ (five prime) and the other end is referred to as 3′ (three prime). The 5′ and 3′ designations refer to the number of carbon atom in a deoxyribose sugar molecule to which a phosphate group bonds.

What does 3 prime and 5 Prime mean in a DNA molecule?

Answered 4 years ago. The “five prime” and “three prime” indicate the carbon numbers in the DNA’s sugar backbone. The 5 prime carbon has a phosphate group attached to it and the 3 prime carbon a hydroxyl group. This asymmetry gives a DNA strand a “direction”.

Does DNA replication occur 5 prime to 3 prime?

DNA replication goes in the 5′ to 3′ direction because DNA polymerase acts on the 3′-OH of the existing strand for adding free nucleotides.

Why does DNA polymerase go from 5 to 3?

Since DNA polymerase requires a free 3′ OH group for initiation of synthesis, it can synthesize in only one direction by extending the 3′ end of the preexisting nucleotide chain. Hence, DNA polymerase moves along the template strand in a 3’–5′ direction, and the daughter strand is formed in a 5’–3′ direction.

Why is it called 5 end?

The 5′-end (pronounced “five prime end”) designates the end of the DNA or RNA strand that has the fifth carbon in the sugar-ring of the deoxyribose or ribose at its terminus.

Is the leading strand 5 to 3?

One new strand, which runs 5′ to 3′ towards the replication fork, is the easy one. This strand is made continuously, because the DNA polymerase is moving in the same direction as the replication fork. This continuously synthesized strand is called the leading strand.

How do you know which end is 3 and 5?

3′ end/5′ end: A nucleic acid strand is inherently directional, and the “5 prime end” has a free hydroxyl (or phosphate) on a 5′ carbon and the “3 prime end” has a free hydroxyl (or phosphate) on a 3′ carbon (carbon atoms in the sugar ring are numbered from 1′ to 5′).

Why do Okazaki fragments form?

Okazaki fragments form because the lagging strand that is being formed have to be formed in segments of 100–200 nucleotides. This is done DNA polymerase making small RNA primers along the lagging strand which are produced much more slowly than the process of DNA synthesis on the leading strand.

Which is 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.

How do you know if its a leading or lagging strand?

When replication begins, the two parent DNA strands are separated. One of these is called the leading strand, and it is replicated continuously in the 3′ to 5′ direction. The other strand is the lagging strand, and it is replicated discontinuously in short sections.

What is the function of Okazaki fragments?

Okazaki fragments are short sequences of DNA nucleotides (approximately 150 to 200 base pairs long in eukaryotes) which are synthesized discontinuously and later linked together by the enzyme DNA ligase to create the lagging strand during DNA replication.

What is lagging strand in DNA?

The lagging strand is the strand of nascent DNA whose direction of synthesis is opposite to the direction of the growing replication fork.

Why is it called the lagging strand?

The double stranded DNA is first unzipped by an enzyme called helicase. Because of the different directions the two enzymes moves on the lagging strand, the DNA chain is only synthetised in small fragments. Hence it is called the lagging strand.

Is the lagging strand synthesized 5 to 3?

Figure 27.27. Okazaki Fragments. At a replication fork, both strands are synthesized in a 5′ → 3′ direction. The leading strand is synthesized continuously, whereas the lagging strand is synthesized in short pieces termed Okazaki fragments.

Why are Okazaki fragments discontinuous?

On the upper lagging strand, synthesis is discontinuous, since new RNA primers must be added as opening of the replication fork continues to expose new template. This produces a series of disconnected Okazaki fragments.

What is the lagging strand synthesized by?

Leading strand synthesis, once initiated, occurs in a highly processive and continuous manner by a proofreading DNA polymerase. Unlike leading strands, lagging strands are synthesized as discrete short DNA fragments, termed ‘Okazaki fragments’ which are later joined to form continuous duplex DNA.

What is Primase made of?

Archaeal and eukaryote primases are heterodimeric proteins with one large regulatory (human PRIM2, p58) and one small catalytic subunit (human PRIM1, p48/p49). The large subunit contains a N-terminal 4Fe–4S cluster, split out in some archaea as PriX/PriCT.

Why does DNA polymerase need a primer?

The synthesis of a primer is necessary because the enzymes that synthesize DNA, which are called DNA polymerases, can only attach new DNA nucleotides to an existing strand of nucleotides. The primer therefore serves to prime and lay a foundation for DNA synthesis.