Notes for DNA & RNA

DNA RNA• Double stranded Single stranded

• Uses the base T Uses the base U

• Sugar is deoxyribose Sugar is ribose

3 types of RNA1. mRNA2. tRNA3. rRNA

1. mRNAMessenger RNA• Takes the code on DNA

from the nucleus to the ribosome.

mRNA

2. tRNATransfer RNA•Brings the amino acids (AA)

to the ribosome.Note: AA+AA+AA= protein

tRNA

Amino Acid Attachment Site

Anticodon Loop

3. rRNARibosomal RNA•Makes up part of the

ribosome.

mRNA

tRNA

rRNA

Transcription• This occurs first!• It is the DNA coding into RNA

Note: This has to happen because DNA is trapped in the nucleus and can NEVER leave. The RNA takes the code to the ribosomes.

Translation• This is when the mRNA is

decoded and proteins are assembled.• The enzyme that cuts DNA to

make mRNA is called RNA polymerase.

mRNA

tRNA

Amino Acids

Code this DNA into RNA…

A T T G CU A A C G

Translation

• The mRNA arrives at the ribosome.• tRNA brings AA and arranges them

according to the codons on the mRNA• The anticodon (3 bases) matches up

the correct codon (3 bases)• P. 308-309

End of Translation