DNA & RNA

DNA -

• deoxyrionucleic acid and contains the 5 carbon sugar deoxyribose
• a double stranded molecule
• contains 4 bases Adenine (A) , Cytosine (C), Guanine (G) and Thymine (T).
• DNA, being double stranded is too large to pass out of the nuclear pores and so is confined to the nucleus.
• DNA can undergo self replication, RNA can't

RNA-

• RNA is ribonucleic acid and contains the 5 carbon sugar ribose.
• RNA is single stranded
• In RNA Thymine is replaced by Uracil(U) but also contains A, C and G.
• has several types: Messenger RNA(mRNA), Transfer RNA (tRNA) and Ribosomal (rRNA)
• mRNA is copied from one strand of DNA by a process called Transcription

-Both DNA are composed of sub units called nucleotides.

-A Nucleotide has 3 sub units: A 5 carbon sugar, An inorganic phosphate and one of four bases.

-The nucleotides in both DNA and RNA are linked by chemical bonds between the sugar of one nucleotide and the Phosphate of the next to form a 'sugar- phosphate backbone'.
-Proteins are coded for by sequences of three bases on the nucleic acid strands.
-A series of three bases on DNA is called a Triplet. On mRNA a sequence of three bases is called a codon and on tRNA it is called an anticodon.