The molecule of life

how does dna store genetic information

DNA stores information as a sequence of four chemical bases, and the order in which those bases appear along the strand is the code itself, much like letters spelling out words. This course walks through how that sequence carries meaning and why the arrangement of bases is what matters.

what are the four bases in dna

The four bases are adenine, thymine, guanine, and cytosine, usually shortened to A, T, G, and C. Their order along the molecule is what encodes information, and the course looks closely at how these four letters combine to spell out instructions.

why does dna have a double helix shape

The double helix is two strands twisting around each other, held together where the bases meet in the middle. This structure lets the information be protected on the inside while still allowing the strands to come apart when needed, an elegance the course takes time to appreciate.

how do the two strands of dna pair up

The bases pair in a fixed way: A always sits opposite T, and G always sits opposite C. Because of this rule, each strand mirrors the other, so one side can be rebuilt from the other, which is something the course explains from the ground up.

what makes dna good at holding information

A small alphabet of four bases arranged in a long sequence can spell out an enormous amount of instruction, and the paired structure keeps a backup copy built into the molecule. The course focuses on why this design is such a reliable and elegant way to store information.