NUCLEIC ACIDS

Today, we want to look at the structure of DNA and RNA.

STRUCTURE OF DNA

DNA stands for deoxyribonucleic acid. This is the basic unit of our genes. DNA consist of a sugar molecule called deoxyribose, a phosphate, and nitrogen bases. These three things make up the nucleotide. So we can say that the basic unit of the DNA is the nucleotide. The sugar and the phosphate together make up the nucleoside.

The nitrogen bases are adenine (A), guanine (G), cytosine (C), and thiamine (T).

Adenine (A) always binds to thiamine (T)

Guanine (G) always binds to cytosine (C)

DNA is located in the nucleus of the cell and it has a double helix structure.

STRUCTURE OF RNA

RNA stands for ribonucleic acid. This is involved with the synthesis of protein. RNA consist of a sugar molecule called ribose, a phosphate, and nitrogen bases. These three things make up the nucleotide. So we can say that the basic unit of the RNA is the nucleotide. The sugar and the phosphate together make up the nucleoside.

The nitrogen bases are adenine (A), guanine (G), cytosine (C), and Uracil (U).

Adenine (A) always binds to Uracil (U)

 Guanine (G) always binds to cytosine (C)

RNA is located in the cytoplasm of the cell and it is a single strand.

Types of RNA:
1. mRNA--- Messenger RNA: This is code for protein synthesis. 
2. tRNA ---- Tranfer RNA: This carries the amino acids.
3. rRNA ---- Ribosomal RNA: This reads the code on the mRNA.

Note the difference between DNA and RNA. DNA has thiamine but no uracil. RNA has uracil but no thiamine.