|
STRUCTURE AND FUNCTION OF RNA
RNA is structurally similar to DNA!
Both nucleic acids are sugar-phosphate polymers and both have nitrogen bases attached to the sugars of the backbone- but there are several important differences.
 They differ in composition:
They also differ in size and structure:
 |
1 |
|
RNA molecules are smaller (shorter) than DNA molecules,
| |
|
2 |
|
RNA is single-stranded, not double-stranded like DNA.
| |
Another difference between RNA and DNA is in function. DNA has only one function-STORING GENETIC INFORMATION in its sequence of nucleotide bases. But there are three main kinds of ribonucleic acid, each of which has a specific job to do.
|
1 |
|
Ribosomal RNAs-exist outside the nucleus in the cytoplasm of a cell in structures called ribosomes. Ribosomes are small, granular structures where protein synthesis takes place. Each ribosome is a complex consisting of about 60% ribosomal RNA (rRNA) and 40% protein.
| |
|
2 |
|
Messenger RNAs-are the nucleic acids that "record" information from DNA in the cell nucleus and carry it to the ribosomes and are known as messenger RNAs (mRNA).
| |
|
3 |
|
Transfer RNAs-The function of transfer RNAs (tRNA) is to deliver amino acids one by one to protein chains growing at ribosomes.
| |
|
