Final answer:
A DNA strand is comprised of nucleotides, which form genes, the basis for protein synthesis. The structural integrity of DNA is maintained through its double helix formation and antiparallel strands linked by base pairings of adenine with thymine and cytosine with guanine.
Step-by-step explanation:
A DNA strand is made of nucleotides which make up genes which in turn encode for the construction of proteins, often regarded as the sentences in the language of life. A DNA molecule is composed of two strands that twist around each other to form a helix, known as a double helix. These two strands run antiparallel, meaning one strand is oriented in the 5' to 3' direction and the other in the 3' to 5' direction. The backbone of each DNA strand consists of a sugar-phosphate structure, with the sugars being deoxyribose. Connecting these backbones are nitrogenous base pairs; adenine (A) always pairs with thymine (T), and cytosine (C) pairs with guanine (G), held together by hydrogen bonds. These base pairings contribute to the DNA's ladder-like structure with the paired bases acting like rungs.
A DNA strand is made of alternating sugar and phosphate groups, which make up the backbone, and nitrogen bases, which make up the rungs. The two DNA strands form a double helix structure, with the nitrogen bases on one strand pairing with specific bases on the other strand. These base pairings follow specific rules: adenine pairs with thymine, and guanine pairs with cytosine.