ROLe of DNA in the cell:
The major function of DNA is to encode the sequence of amino acid residues in proteins, using the genetic code. To read the genetic code, cells make a copy of a stretch of DNA in the nucleic acid RNA (Science Daily: 10 September, 2014). DNA provides the instructions for protein synthesis- making proteins in the cell.
The types of proteins a cell can make are determined by genes, which are parts of the DNA molecules in the nucleus. The order of which the bases occur is classified as the genetic code. Each sequence of a couple of bases is the code for a particular amino acid. Amino acids are essentially assembled in the ribosomes and instructions contained in the DNA must be accurately transferred to the ribosomes. To transfer coded information to the ribosomes, some of the DNA molecule breaks apart, creating a segment of RNA, called messenger RNA or mRNA. (bases are complementary to that of DNA). The messenger RNA passes through the nucleus and reaches the ribosome. Here the amino acids are joined together carefully determined by the messenger RNA, creating another form of RNA, transfer RNA or tRNA. This RNA brings the amino acids from the cytoplasm to the ribosomes.
The types of proteins a cell can make are determined by genes, which are parts of the DNA molecules in the nucleus. The order of which the bases occur is classified as the genetic code. Each sequence of a couple of bases is the code for a particular amino acid. Amino acids are essentially assembled in the ribosomes and instructions contained in the DNA must be accurately transferred to the ribosomes. To transfer coded information to the ribosomes, some of the DNA molecule breaks apart, creating a segment of RNA, called messenger RNA or mRNA. (bases are complementary to that of DNA). The messenger RNA passes through the nucleus and reaches the ribosome. Here the amino acids are joined together carefully determined by the messenger RNA, creating another form of RNA, transfer RNA or tRNA. This RNA brings the amino acids from the cytoplasm to the ribosomes.