Protein Synthesis Notes
Comparing DNA & RNA
DNA
RNA
 Double stranded
 Single stranded
 Deoxyribose sugar
 Ribose sugar
 Bases include
 Bases include




Adenine
Thymine
Guanine
Cytosine
 Function: DNA has the
instructions for
building proteins




Adenine
Uracil
Guanine
Cytosine
 Function: RNA carries
out the instructions
for building proteins
Three Types of RNA
Name
Role of RNA
mRNA – messenger RNA
Has the instructions for making
proteins from DNA
tRNA – transfer RNA
Transfers amino acids to ribosome
rRNA – ribosomal RNA
Helps with translation
***ALL THREE are involved in protein synthesis!***
From DNA to Proteins
 Gene: portion of DNA that codes for a specific
protein
 Codon: a group of 3 bases that code for an amino
acid on the mRNA
 Anticodon: a group of 3 bases on the tRNA that
help bond to the mRNA
Transcription
Transcription
Transcription occurs when the cell needs to send out instructions
for making proteins
 Where does transcription occur?
 In the nucleus of eukaryotes OR cytoplasm of
prokaryotes
 How does transcription occur?
*DNA unwinds
*DNA unzips
*a single strand of mRNA is made
 What is produced during transcription?

Single-stranded copy of DNA called mRNA that can
leave the nucleus and go to the cytoplasm
Transcription
Transcription
 Transcription animation
Translation
Translation occurs when the cell uses the mRNA
produced during transcription to make proteins for the
cell.
 Where does translation occur?
On the Ribosomes in the cytoplasm
 What is produced during translation?
Polypeptide chain (a protein)
Translation
nucleus
Translation
 Translation animation
Translation
Transcription and Translation