1. From gene to protein

2. Process of making a protein
DNA -> RNA -> protein
Transcription
RNA polymerase: separates the DNA (helicase does this in replication) then transcribes the DNA into messenger RNA (mRNA)
Promoter – the region of DNA where RNA polymerase binds to
transcription
translation

3. Transcription 5’ 3’ 5’ 3’ DNA T A C G T A C G T A C G A T G C A T G C
RNA polymerase A T G C A T G C A T G C
DNA 5’ 3’

4. 5’ 3’ 3’ 5’ 5’ 3’ Transcription DNA T A C G T A C G T A C G mRNA U A C
RNA polymerase A T G C A T G C A T G C
DNA 5’ 3’

5. Translation mRNA A U G A U G C G U A C G C A T U A C tRNA tRNA
Ribosome – made up of ribosomal RNA (rRNA) and proteins
E site (Exit site)
P site (Peptide site)
A site (Active site)
Small subunit
mRNA A U G A U G C G U A C G C A T U A C
tRNA
tRNA
Large subunit
Amino acid
Amino acid

6. Translation mRNA A U G C G U A C G C A T U A C tRNA tRNA
Ribosome – made up of ribosomal RNA (rRNA) and proteins
E site (Exit site)
P site (Peptide site)
A site (Active site)
Small subunit
mRNA A U G C G U A C G C A T U A C
tRNA
tRNA
Large subunit
Amino acid
Amino acid

7. Translation mRNA A U G C G U A C G C A T U A C U G C tRNA tRNA tRNA
Ribosome – made up of ribosomal RNA (rRNA) and proteins
E site (Exit site)
P site (Peptide site)
A site (Active site)
Small subunit
mRNA A U G C G U A C G C A T U A C U G C
tRNA
tRNA
tRNA
Amino acid
Amino acid
Amino acid

8. Translation mRNA A U G C G U A C G C A T U A C tRNA tRNA
Ribosome – made up of ribosomal RNA (rRNA) and proteins
E site (Exit site)
P site (Peptide site)
A site (Active site)
Small subunit
mRNA A U G C G U A C G C A T U A C
codon
anticodon
tRNA
tRNA
Large subunit
Amino acid
Amino acid

9. Genetic Code

10. Alternative splice Primary RNA transcript processed
Alternative splicing – when a region of DNA has different introns cut out to form different products

11. Post-transcriptional control5’
mRNA 3’
exon
exon
exon A A A A A A
5’ cap
3’-poly-A tail
5’ cap and 3’-poly-A tail prevent degradation

12. Transcriptional Control in prokaryotes
RNA polymerase
Repressor
promoter
operator
Gene
DNA

13. Lac operon – an example of translational control
activator
cAMP
lactose
CAP
RNA polymerase
Repressor
operator
Group of genes = operon
promoter
CAP-binding site
DNA

14. Transcriptional Control in Eukaryotes
Transcription factor
RNA polymerase
Activator
Gene
Enhancer
promoter
DNA
Transcription factor bound to RNA polymerase is called an initiation complex

15. Post-translational modifications
Once you’ve made your protein, you can add other chemicals to the protein surface to alter its function
Sugars
Phosphate