Q:

What makes up the sides of the ladder of a DNA molecule?

A:

Quick Answer

A rigid chain of alternating deoxyribose sugars and phosphates makes up the sides of the DNA ladder. The rungs of the DNA ladder consist of four nitrogenous bases.

Know More
What makes up the sides of the ladder of a DNA molecule?
Credit: Bjorn Holland Photodisc Getty Images

Full Answer

Adenine, guanine, thymine and cytosine are the four nitrogenous bases that are attached to a sugar molecule on each side of the ladder. When a phosphate, a sugar and a base form an attachment, they create a subunit of DNA called a nucleotide. Each nitrogenous base is held together by a hydrogen bond. Nitrogen base bonding is very specific, and each base can only pair with the correctly matching base. Adenine and thymine pair together, as do guanine and cytosine pair together. The way these nitrogenous bases are arranged is extremely important. The alignment of these base pairs determines the type of organism being formed, whether it is a plant or an animal. The structure of a DNA strand resembles a right-handed double helix. This compact helical arrangement allows more genetic information to be stored within a single strand of DNA. The purpose of the sides of the ladder, the sugar-phosphate chain, is to keep the genetic code in its proper order. If this structure becomes unstable, the genetic code may be altered and mutations could arise in the cell.

Learn more in Molecular Biology & DNA

Related Questions

  • Q:

    What is the shape of a DNA molecule?

    A:

    The shape of a DNA molecule is called a double helix, which looks like a twisting ladder. The "rungs" are made from four nitrogenous bases: adenine, thymine, guanine and cytosine. Sugars and phosphate groups are also part of the structure.

    Full Answer >
  • Q:

    What makes up the backbone of the DNA molecule?

    A:

    Two components make the backbone in DNA, being the deoxy-ribose and phosphate molecules. These molecules link together in a staggered pattern where the deoxy-ribose and phosphate molecules follow one another, like the backbone of a zipper. Deoxy-ribose is a type of sugar molecule where the adenine, guanine, cytosine and thymine molecules attach a covalent bond. The phosphate molecules bond with the deoxy-ribose molecule acting like anchors in DNA.

    Full Answer >
  • Q:

    What makes up the rungs of the DNA molecule?

    A:

    As shown on the NIH Genetics Home Reference site, when DNA molecules are represented as ladders, the rungs represent the base pairs of the DNA. The bases in DNA are often represented as G, A, T and C, which stand for guanine, adenine, thymine and cytosine. When two strands of DNA form a double-strand helix, the bases pair up in the middle of the molecule.

    Full Answer >
  • Q:

    What makes up the steps of a DNA molecule?

    A:

    The "steps" or "rungs" of a DNA molecule are made up of four nucleobases, including adenine (A), cytosine (C), guanine (G) and thymine (T). These bases are arranged in particular pairs. A only bonds with T and vice versa, while C only pairs with G and vice versa.

    Full Answer >

Explore