Differences between DNA and RNA (RNA vs DNA)

○ Carbon #2 on the pentose is not “deoxygenated” (it has a hydroxyl group attached).

○ RNA is single stranded.

○ RNA contains uracil instead of thymine.

○ RNA can move through the nuclear pores and isn’t confined to the nucleus.

Types of RNA

RNA exists in 3 forms:

1) mRNA

○ Delivers the DNA code for amino acids to the cytosol where the proteins are manufactured.

○ Has a short half-life in the cytosol, so soon after its transcription is over, the mRNA is degraded.

○ Many proteins can be transcribed in a single mRNA.

2) rRNA

○ Combines with proteins to form ribosomes, the cellular complexes that direct the synthesis of proteins.

○ rRNA is synthesized in the nucleolus.

3) tRNA

○ Collects amino acids in the cytosol, and transfers them to the ribosomes for incorporation into a protein.

mRNA → massive

rRNA → rampant

tRNA → tiny