What is meant by the description antiparallel regarding the two strands of DNA?
What is meant by the description antiparallel regarding the two strands of DNA?
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 quizlet?
DNA polymerase III adds DNA nucleotides to the primer(s), synthesizing the DNA of both the leading and the lagging strands.
Which part of a DNA molecule is hydrophobic?
The sugar-phosphate backbone of DNA is polar, and therefore hydrophillic; thus it likes to be proximal to water. The interior portion of DNA, the bases, are relatively non-polar and therefore hydrophobic.
Are there hydrophobic interactions in DNA?
The research team said it has shown that the secret to DNA’s helical structure may be that the molecules have a hydrophobic interior, in an environment consisting mainly of water. The environment is therefore hydrophilic, while the DNA molecules’ nitrogen bases are hydrophobic, pushing away the surrounding water.
Are DNA and RNA hydrophobic?
Also note that the backbones of both DNA and RNA are hydrophilic. The hydroxyl groups of the sugar residues form hydrogen bonds with water. The backbone of alternating 3′ pentose and phosphate groups of both DNA andRNA is highly polar.
What keeps DNA together?
The nucleotides in a base pair are complementary which means their shape allows them to bond together with hydrogen bonds. The hydrogen bonding between complementary bases holds the two strands of DNA together. Hydrogen bonds are not chemical bonds.
What holds the two helixes in DNA together?
The DNA double helix is held together by hydrogen bonds between the bases attached to the two strands. The DNA double helix. The two sides are the sugar-phosphate backbones, composed of alternating phosphate groups and deoxyribose sugars.
What is the weak bond that holds the 2 strands together?
Hydrogen bonds
How are two DNA strands attracted to one another?
Covalent bonds occur within each linear strand and strongly bond the bases, sugars, and phosphate groups (both within each component and between components). Hydrogen bonds occur between the two strands and involve a base from one strand with a base from the second in complementary pairing.
What is the 3 prime end of 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 is the complementary strand of DNA?
Complementary deoxyribonucleic acid (DNA) is DNA in which the sequence of the constituent molecules on one strand of the double stranded structure chemically matches the sequence on the other strand. A useful analog is to picture a key and a lock. Complementary DNA (cDNA) is a copy of a region of a strand of DNA.
What are the factors that stabilize the DNA structure?
The structure of the DNA helix is stabilized by van der Waals forces, hydrogen bonds between complementary organic bases (a base pair), and hydrophobic interactions between the nitrogenous bases and the surrounding sheath of water.
Which type of DNA is more stable?
DNA can adopt one of several different double helix structures: these are the A, B and Z forms of DNA. The B form, the most stable under cellular conditions, is considered the “standard” form; it’s the one you typically see in illustrations. The A form is a double helix but but is much more compressed than the B form.
Which two metals are responsible for stabilization of DNA?
It was determined that potassium and barium had no effect on the melting temperature, while magnesium and calcium increased the melting temperature. Furthermore, magnesium outperformed calcium and was found to be the most effective ion at higher concentrations for stabilizing DNA.
Which base pairs are found in DNA?
The two strands are held together by hydrogen bonds between the bases, with adenine forming a base pair with thymine, and cytosine forming a base pair with guanine.
How do you count base pairs in DNA?
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)
Why does adenine only pair with thymine in DNA?
Adenine and Thymine also have a favorable configuration for their bonds. They both have to -OH/-NH groups which can form hydrogen bridges. When one pairs Adenine with Cytosine, the various groups are in each others way. For them to bond with each other would be chemically unfavorable.
What are the names of the two strands of DNA?
The two DNA strands are known as polynucleotides as they are composed of simpler monomeric units called nucleotides. Each nucleotide is composed of one of four nitrogen-containing nucleobases (cytosine [C], guanine [G], adenine [A] or thymine [T]), a sugar called deoxyribose, and a phosphate group.
Is it biologically advantageous that DNA is stable?
Is it biologically advantageous that DNA stable? Yes. It has all the information required by the cell for its structure and functions. If it were stable molecule, the synthesis of proteins would continue even if there was no need for that protein, resulting in wastage of energy and prove to be harmful for the cell.
What makes a DNA strand?
DNA is made of chemical building blocks called nucleotides. To form a strand of DNA, nucleotides are linked into chains, with the phosphate and sugar groups alternating. The four types of nitrogen bases found in nucleotides are: adenine (A), thymine (T), guanine (G) and cytosine (C).
What two components make up the backbone of DNA?
DNA consists of two strands that wind around each other like a twisted ladder. Each strand has a backbone made of alternating sugar (deoxyribose) and phosphate groups.
What makes up the backbone of DNA quizlet?
What is the “backbone” of DNA composed of? Phosphate molecules and deoxyribose sugar. DNA backbones are made up of deoxyribose, a pentose sugar. These sugars are connected via a phosphodiester bond.