dna (deoxyribonucleic acid) consists of three components
TRANSCRIPT
DNA (deoxyribonucleic acid) consists of three components.
It contains a phosphate group.
A sugar molecule, deoxyribose, is attached to the phosphate groups.
A base is attached to each sugar molecule. In this example, the base is a pyrimidine.
The monomer unit of DNA is the nucleotide. One nucleotide comprises a phosphate group, sugar molecule and a base.
The base may also be a purine. DNA contains equal amounts of pyrimidines and purines.
Nucleotides join end to end to form a strand of polynucleotide. DNA contains two polynucleotide strands.
Nucleotides join end to end to form a strand of polynucleotide. DNA contains two polynucleotide strands.
Nucleotides join end to end to form a strand of polynucleotide. DNA contains two polynucleotide strands.
Nucleotides join end to end to form a strand of polynucleotide. DNA contains two polynucleotide strands.
Nucleotides join end to end to form a strand of polynucleotide. DNA contains two polynucleotide strands.
Nucleotides join end to end to form a strand of polynucleotide. DNA contains two polynucleotide strands.
Nucleotides join end to end to form a strand of polynucleotide. DNA contains two polynucleotide strands.
Nucleotides join end to end to form a strand of polynucleotide. DNA contains two polynucleotide strands.
Nucleotides join end to end to form a strand of polynucleotide. DNA contains two polynucleotide strands.
Nucleotides join end to end to form a strand of polynucleotide. DNA contains two polynucleotide strands.
The second polynucleotide strand runs in the opposite direction. The strands twist around each other in a double helix.
Notice how the alternating phosphate groups and sugar molecules form a sugar–phosphate.
Hydrogen bonds are very important in DNA, as they hold the two strands together.
Thymine, shown as T, forms two hydrogen bonds with adenine, shown as A.
Guanine, shown as G, forms three hydrogen bonds with cytosine, shown as C.
Guanine, shown as G, forms three hydrogen bonds with cytosine, shown as C.
A bonds to T, and G bonds to C throughout the structure of DNA, forming complementary base pairs.
A bonds to T, and G bonds to C throughout the structure of DNA, forming complementary base pairs.
A bonds to T, and G bonds to C throughout the structure of DNA, forming complementary base pairs.
This is adenine, a purine.
This is thymine, a pyrimidine.
Two hydrogen bonds can form between them.
This is guanine, a purine.
This is cytosine, a pyrimidine.
Three hydrogen bonds can form between them.