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What is the shape of a DNA molecule?
double helix
The DNA molecule consists of two strands that wind around one another to form a shape known as a double helix. Each strand has a backbone made of alternating sugar (deoxyribose) and phosphate groups. Attached to each sugar is one of four bases–adenine (A), cytosine (C), guanine (G), and thymine (T).
What is the size and shape of a DNA molecule?
The DNA molecule is shaped like a ladder that is twisted into a coiled configuration called a double helix. The nitrogen bases form the rungs of the ladder and are arranged in pairs, which are connected to each other by chemical bonds.
What is structure of pyrimidine?
pyrimidine, any of a class of organic compounds of the heterocyclic series characterized by a ring structure composed of four carbon atoms and two nitrogen atoms. The simplest member of the family is pyrimidine itself, with molecular formula C4H4N2.
What are deoxyribose nucleotides?
A DNA nucleotide is composed of a deoxyribose (five carbon sugar) with an attached nitrogenous base (adenine [A], guanine [G], cytosine [C], or thymine [T]) and a phosphate group.
What color is deoxyribose?
Figure 1: A single nucleotide contains a nitrogenous base (red), a deoxyribose sugar molecule (gray), and a phosphate group attached to the 5′ side of the sugar (indicated by light gray).
What shape is DNA like?
How is a DNA molecule arranged?
How is the DNA strand organized? Double-stranded DNA consists of two polynucleotides that are arranged such that the nitrogenous bases within one polynucleotide are attached to the nitrogenous bases within another polynucleotide by way of special chemical bonds called hydrogen bonds.
What are the pyrimidine nucleotides?
The nitrogenous bases found in nucleotides are classified as pyrimidines or purines. Pyrimidines are heterocyclic amines with two nitrogen atoms in a six-member ring and include uracil, thymine, and cytosine. Adenine and guanine are the major purines found in nucleic acids (Figure 28.1.
What is the chemical structure of deoxyribose?
Its chemical structure allows for the replication of cells in DNA’s double helix configuration. Deoxyribose contains 5 carbon atoms that are arranged to form the sugar’s pentagonal shape. Compared to other pentose sugars, deoxyribose is considered a modified sugar due to the fact that it only has four oxygen atoms.
Why is deoxyribose considered a modified sugar?
Deoxyribose is considered a modified sugar because it only has four oxygen atoms. Ribose and deoxyribose are involved in creating DNA and ribonucleic acid (RNA), which we will discuss later. Too much sugar is not always a bad thing.
Does the deoxyribose base change from one nucleotide to the next?
Although the deoxyribose base does not change from one nucleotide to the next, it creates a strong support for the working molecules of DNA. The only difference between RNA and DNA is the presence of deoxyribose instead of ribose. An enzyme known as ribonucleotide reductase removes an oxygen molecule from one of the carbons of a ribose sugar.
Is 2-deoxyribose a monosaccharide?
?) Deoxyribose, or more precisely 2-deoxyribose, is a monosaccharide with idealized formula H− (C=O)− (CH 2 )− (CHOH) 3 −H. Its name indicates that it is a deoxy sugar, meaning that it is derived from the sugar ribose by loss of an oxygen atom.