DNA contains genes that code for proteins. During transcription, mRNA is produced by copying DNA in the nucleus. The mRNA then transports the genetic code to the cytoplasm for translation at the ribosome. Translation is the process where tRNA brings amino acids to the ribosome according to the mRNA codons to produce a protein, consisting of a chain of amino acids specified by the DNA.

1. RNA and Protein
Synthesis

4. Chromosome
DNA
Gene

5. Sections within a gene
CODONS
TAC
Codes for protein
Codon base triplets
Examples ATC CCG
Stop CodonStart Codon
ATT, ATC, or ACT

6. Codons, Amino Acid & Protein
 One codon codes for one amino acid
EX: ACG = amino acid (threonine)
CGC = amino acid (arginine)
GGA = aminio acid (glycine)
A sequence of amino acids is a protein
ACG
GGA
GGC
CCA
AAC
CCG
GCCCGC
Threonine
Arginine
Glycine
Glycine
Proline
Asparagine
Proline
Alanine
Amino Acid
Protein

7. RNA
- Ribonucleic acid
- Single stranded
- Sugar is ribose
- Uracil replaces thymine
- Types of RNA
- mRNA – messenger – transcription
- tRNA – transfer - translation
- rRNA – ribosomal – makes up part of ribosome

8. DNA vs RNA
 Contains deoxyribose
sugar
 Is double stranded
 Bonds A-T and C-G
 Never leaves the nucleus
 Contains ribose sugar
 Is single stranded
 Bonds A-U and C-G
 Can leave the nucleus

9. How Does RNA Help?
 DNA - contains the master code
tRNA
towing
Amino acid
mRNA
Protein
factory
tRNA, transfer RNA
carries amino acids
rRNA, ribosomal RNA
guides the process in the
ribosome
mRNA, messenger RNA
copies/carries the DNA code
Chromosome DNA

11. gene expression
 mRNA copies DNA in nucleus –
transcription
 Takes copy to ribosome
 tRNA brings amino acids to
ribosome - translation
Transcription Translation

12. TRANSCRIPTION
 TRANSCRIPTION: mRNA is made
copying DNA’s code
Uses enzymes
Makes mRNA from DNA template
Occurs in the nucleus
click to play animation

13. TRANSLATION
 Process when the protein is actually
made
• Uses an anticodon to the tRNA
to bring an amino acid to the
ribosome
• Occurs at the ribosome in
the cytoplasm
click to play animation

15. Messenger RNA Codons

17. What does the chain of amino acids represent?
Threonine
Arginine
Glycine
Glycine
Proline
Asparagine
Proline
Alanine
Polypeptide Chain – A Protein

18. What is the monomer (subunit) for protein?
What are the functions of protein?
Name examples of proteins.
amino acids
structure or support; enzymes speed up
chemical reactions
muscles, hair, cartilage, nails

19. SUMMARY Transcription  Translation
G
A
C
G
A
U
A
A
T
T
T
C
C
A
G
G
C
G
DNA mRNA
A U U
Amino Acid
tRNA Protein
Occurs in the Occurs in the
DNA
DNA has the
master code
mRNA is made,
copying DNA’s code
A protein is made