DNA

**Information:** DNA (deoxyribonucleic acid) is twisted into a right-handed double helix, which is made out of two complementary DNA strands. The double-stranded DNA strands are antiparallel to each other, ie the polarity of one strand is opposite to the polarity of the second strand of DNA (if at one end the first strand 3' ends, the other strand will end at the same end 5'). Hydrogen bonds and these double helices contribute to maximize the stabilization of the DNA molecule.

**Importance of DNA:** DNA is a very important substance for life – it bears the genetic information of all living organisms. When dividing a cell, all of the DNA molecules contained in the nucleus replicate (two identical double-helix are formed from one DNA molecule), so that both cell divisions have identical DNA molecules (identical genetic apparatus). In the DNA, the sequence (primary structure) of all proteins is written. This information can be transcribed from DNA into RNA (transcription) and subsequently used (translational process) for protein synthesis (proteosynthesis). DNA is located in nuclei and semi-autonomous organelles (e.g., in mitochondria).

**Model description:** The model shows a short stretch of the DNA molecule (only 12 nucleotide pairs). The DNA is made out of two strings (filaments) that are twisted into a helix. The filaments are interconnected by hydrogen bonds, which are formed between complementary nitrogen bases. The model specifically depicts the CGCTATAATGCG nucleotide sequence and the complementary CGCATTATAGCG (both strands written in the 5'→3' direction).