What describes the structure of DNA?
DNA is the molecule that holds the instructions for growth and development in every living thing. Its structure is described as a double-stranded helix held together by complementary base pairs. The basic units of DNA are nucleotides. These nucleotides consist of a deoxyribose sugar, phosphate and base.
How is the structure of DNA related to its function?
DNA is made up of two nucleic acid strands joined by hydrogen bonding. DNA winds into a double helix, with hydrogen bonding between the bases of each strand like the rungs of a ladder. This structure enables DNA to coil so that the long molecule is compact and lots of information can be stored in a small space.
What is DNA What is its function?
DNA structure and function. DNA is the information molecule. It stores instructions for making other large molecules, called proteins. These instructions are stored inside each of your cells, distributed among 46 long structures called chromosomes.
What are the 4 chemicals that make up DNA?
The four types of nitrogen bases found in nucleotides are: adenine (A), thymine (T), guanine (G) and cytosine (C). The order, or sequence, of these bases determines what biological instructions are contained in a strand of DNA.
How long is a DNA?
about 3 meters
Is human DNA one strand long?
No. Each chromosome is made of two opposite and parallel strands of DNA. Each chromosome is a single long’s strand of DNA. Nitpick: Except during mitosis, which is the only time the chromosomes are visible as discrete structures.
What is a strand of DNA called?
A DNA molecule consists of two long polynucleotide chains composed of four types of nucleotide subunits. Each of these chains is known as a DNA chain, or a DNA strand. Hydrogen bonds between the base portions of the nucleotides hold the two chains together (Figure 4-3).
How do you read a strand of DNA?
During transcription, the RNA polymerase read the template DNA strand in the 3′→5′ direction, but the mRNA is formed in the 5′ to 3′ direction. The mRNA is single-stranded and therefore only contains three possible reading frames, of which only one is translated.
What are the parts of a DNA model?
DNA has three types of chemical component: phosphate, a sugar called deoxyribose, and four nitrogenous bases—adenine, guanine, cytosine, and thymine. Two of the bases, adenine and guanine, have a double-ring structure characteristic of a type of chemical called a purine.
What holds the bases of DNA together?
Base Pair. 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.
What two components make up the backbone of DNA?
Phosphate Backbone A phosphate backbone is the portion of the DNA double helix that provides structural support to the molecule. 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.